AMTECH SYSTEMS INC

NOTES TO CONDENSED CONSOLI DATED FINANCIAL STATEMENTS

THREE AND NINE MONTHS ENDED JUNE 30, 2025 AND 2024

(UNAUDITED)

1. Basis of Presentation and Significant Accounting Policies

Nature of Operations and Basis of Presentation– Amtech provides equipment, consumables and services for semiconductor wafer fabrication and device packaging. Our products are used in fabricating semiconductor devices, such as silicon carbide (SiC) and silicon (Si) power devices, digital and analog devices, power electronic packages, advanced semiconductor packages and electronic assemblies. We sell these products to semiconductor device and module manufacturers worldwide, particularly in Asia, North America and Europe.

We serve niche markets in industries that are experiencing technological advances, and which historically have been very cyclical. Therefore, our future profitability and growth depend on our ability to develop or acquire and market profitable new products and on our ability to adapt to cyclical trends.

The accompanying unaudited condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”), and consequently do not include all disclosures normally required by accounting principles generally accepted in the United States of America (“GAAP”). In the opinion of management, the accompanying unaudited interim condensed consolidated financial statements contain all adjustments necessary, all of which are of a normal and recurring nature, to present fairly our financial position, results of operations and cash flows. Certain information and note disclosures normally included in financial statements have been condensed or omitted pursuant to the rules and regulations of the SEC. The condensed consolidated balance sheet at September 30, 2024, has been derived from the audited consolidated financial statements at that date but does not include all of the information and footnotes required by GAAP for complete financial statements. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the fiscal year ended September 30, 2024.

Our fiscal year is from October 1 to September 30. Unless otherwise stated, references to particular years, quarters, months or periods refer to our fiscal years ending or ended September 30, and the associated quarters, months, and periods of those fiscal years.

The consolidated results of operations for the three and nine months ended June 30, 2025, are not necessarily indicative of the results to be expected for the full fiscal year.

Principles of Consolidation– The consolidated financial statements include the accounts of the Company and our wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.

Use of Estimates – The preparation of consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates.

Reclassifications – Certain reclassifications have been made to prior year financial statement footnotes to conform to the current year presentation. These reclassifications, which include the breakout of contract liability activity, had no effect on the previously reported consolidated financial statements for any period.

Accounts Receivable and Allowance for Credit Losses– Accounts receivable are recorded at the sales price of products sold to customers on trade credit terms. We establish a valuation allowance to reflect our best estimate of expected losses inherent in our accounts receivable balance. The allowance is based on our evaluation of the aging of the receivables, historical write-offs, the current economic environment and communications with the customer. We write off individual accounts against the allowance when we no longer believe that it is probable that we will collect the receivable because we become aware of a customer’s inability to meet its financial obligations.

Intangible Assets – Intangible assets acquired in business combinations are capitalized and subsequently amortized on a straight-line basis over their estimated useful life. We review our intangible assets for impairment when events or circumstances indicate the carrying value may not be recoverable. When indicators exist, recoverability of assets is measured by a comparison of the carrying value of the asset group to the estimated undiscounted future net cash flows expected to be generated by the asset group. If the asset group is determined not to be recoverable, the Company performs an analysis of the fair value of the individual long-lived assets and will recognize an impairment loss when the fair value is less than the carrying value of such long-lived assets. Additional information on impairment testing of intangible assets can be found in Notes 1 and 9 of our Annual Report on Form 10-K for the year ended September 30, 2024.

In the second quarter of fiscal year 2025 and the first quarter of fiscal year 2024, we recorded impairment of definite lived intangible assets in our Semiconductor Fabrication Solutions segment. See Note 6 for a description of the facts and circumstances leading to the intangible asset impairment.

Goodwill – Goodwill is recorded when the purchase price paid for an acquisition exceeds the estimated fair value of net identified tangible and intangible assets acquired. Goodwill is not subject to amortization but is tested for impairment annually or when it is determined that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If it is concluded that there is impairment, we would recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value (although the loss would not exceed the total amount of goodwill allocated to the reporting unit). Additional information on impairment testing of goodwill can be found in Notes 1 and 10 of our Annual Report on Form 10-K for the year ended September 30, 2024.

In the second quarter of fiscal year 2025, we recorded an impairment of goodwill in our Semiconductor Fabrication Solutions and Thermal Processing Solutions segments. Additionally, we recorded an impairment of goodwill in our Semiconductor Fabrication Solutions segment in the first quarter of fiscal year 2024. See Note 6 for a description of the facts and circumstances leading to goodwill impairment.

Contract Liabilities– Contract liabilities are reflected in current liabilities on the Condensed Consolidated Balance Sheets as all performance obligations are expected to be satisfied within the next 12 months. Contract liabilities relate to payments invoiced or received in advance of completion of performance obligations under a contract. Contract liabilities are recognized as revenue upon the fulfillment of performance obligations. Contract liabilities consist of customer deposits and deferred revenue as of June 30, 2025 and September 30, 2024.

The following is a summary of activity for contract liabilities, in thousands:

As of June 30, 2025, we had approximately$21.2 million of remaining performance obligations, which included recognized contract liabilities as well as amounts to be invoiced and recognized in future periods. As of September 30, 2024, we had approximately $25.3 million of remaining performance obligations. The orders included in our remaining performance obligations are expected to ship within the next twelve months.

Warranty–A limited warranty is provided free of charge, generally for periods of 12 to 36 months to all purchasers of our new products and systems. Accruals are recorded for estimated warranty costs at the time revenue is recognized. While our warranty costs have historically been within our expectations and we believe that the amounts accrued for warranty expenditures are sufficient for all systems sold through June 30, 2025, we cannot guarantee that we will continue to experience a similar level of predictability regarding warranty costs. In addition, technological changes or previously unknown defects in raw materials or components may result in more extensive and frequent warranty service than anticipated, which could result in an increase in our warranty expense.

The following is a summary of activity in accrued warranty expense, in thousands:

Shipping Expense – Shipping and handling fees associated with outbound freight are expensed as incurred and included in selling, general and administrative expenses. Shipping expense was$0.3 millionand $0.5 million for the three months ended June 30, 2025 and 2024, respectively, and$1.0 millionand $1.6 million for thenine months ended June 30, 2025 and 2024, respectively.

Employee Retention Tax – The Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”) provided an employee retention credit (“ERC”) which was a refundable tax credit against certain employment taxes. The Consolidated Appropriations Act (the “Appropriations Act”) extended and expanded the availability of the employee retention credit through December 31, 2021. The Appropriations Act amended the employee retention credit to be equal to 70% of qualified wages paid to employees during the 2021 calendar year. The Company qualified for the employee retention credit for qualified wages through December 2021, and filed a cash refund claim during the calendar year ended December 31, 2023. The employee retention credit in the amount of $2.1 million was received in the Company’s third fiscal quarter of 2025 and recognized as a reduction to payroll tax expense on the Condensed Consolidated Statements of Operations for the three months ended June 30, 2025. The ERC was credited against cost of sales, selling, general and administrative, and research, development and engineering for $1.0 million, $0.8 million, and $0.3 million, respectively.

Concentrations of Credit Risk– Our customers are primarily manufacturers of semiconductor substrates and devices and electronic assemblies. Financial instruments that potentially subject us to significant concentrations of credit risk consist principally of cash and trade accounts receivable. Credit risk is managed by performing credit evaluations of the customers’ financial condition, by requiring significant deposits where appropriate, and by actively monitoring collections. Letters of credit are required of certain customers depending on the size of the order, type of customer or its creditworthiness, and country of domicile.

As of June 30, 2025 and September 30, 2024, one Thermal Processing Solutions customer represented 15% and 12%, respectively, ofaccounts receivable.

We maintain our cash and cash equivalents in multiple financial institutions. Balances in the United States, which account for approximately 72% and 66% of total cash balances as of June 30, 2025 and September 30, 2024, respectively, are primarily invested in financial institutions insured by the FDIC as well as a money market account. The remainder of our cash is maintained with financial institutions with reputable credit in China, the United Kingdom, Singapore and Malaysia. We maintain cash in bank accounts in amounts which at times may exceed federally insured limits. At June 30, 2025 and September 30, 2024 Amtech’s balances exceeded insured limits by approximately $9.7 millionand $5.7 million, respectively. We have not experienced any losses on such accounts.

Refer to Note 11 to Condensed Consolidated Financial Statements for information regarding major customers, foreign sales and revenue in other countries subject to fluctuation in foreign currency exchange rates.

Fair Value of Financial Instruments – We group our financial assets and liabilities measured at fair value on a recurring basis into three levels, based on the markets in which the assets and liabilities are traded, and the reliability of the assumptions used to determine fair value. These levels are:

Level 1 – Valuation is based upon quoted market price for identical instruments traded in active markets.

Level 2 – Valuation is based on quoted market prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets that are not active, and model-based valuation techniques for which all significant assumptions are observable in the market.

Level 3 – Valuation is generated from model-based techniques that use significant assumptions not observable in the market. Valuation techniques include use of discounted cash flow models and similar techniques.

It is our policy to use observable inputs whenever reasonably practicable to minimize the use of unobservable inputs when developing fair value measurements. When available, we use quoted market prices to measure fair value. If market prices are not available, the fair value measurement is based on models that use primarily market-based parameters including interest rate yield curves, option volatilities and currency rates. In certain cases, where market rate assumptions are not available, we are required to make judgments about assumptions market participants would use to estimate the fair value of a financial instrument. Changes in the underlying assumptions used, including discount rates and estimates of future cash flows, could significantly affect current or future valuations.

Cash and Cash Equivalents – Included in cash and cash equivalents in the Consolidated Balance Sheets are money market funds and time deposit accounts. Cash equivalents are classified as Level 1 in the fair value hierarchy.

Receivables and Payables – The recorded amounts of these financial instruments, including accounts receivable and accounts payable, approximate their fair value because of the short maturities of these instruments.

Debt – Our Loan Agreement with UMB Bank was fully repaid in the fourth quarter of fiscal 2024, and was subsequently terminated effective September 11, 2024. The carrying value of debt under our Loan Agreement was based on fixed interest rates. The fair value for the amended Loan Agreement was estimated by discounting the future cash flows using the current rates at which similar loans would be made to borrowers with similar credit ratings and is therefore classified as Level 2 in the fair value hierarchy.

Impact of Recently Issued Accounting Pronouncements

In November 2024, the FASB issued ASU 2024-03, “Income Statement - Reporting Comprehensive Income - Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses” (“ASU 2023-07”), which requires disclosure of additional information about specific expense categories underlying certain income statement expense line items. This ASU is effective for our annual periods beginning October 1, 2027, and interim periods beginning October 1, 2028, and requires either prospective or retrospective application. We are currently evaluating the impact of this ASU on our disclosures.

In December 2023, the FASB issued ASU 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures” (“ASU 2023-09”), which enhances the transparency and decision usefulness of income tax disclosures. Adjustments to the annual disclosure of income taxes include: a tabular rate reconciliation comprised of eight specific categories. Incomes taxes paid, disaggregated between significant federal, state, and foreign jurisdictions. Eliminating requirements to disclose the nature and estimate of reasonably possible changes to unrecognized tax benefits in the next 12 months or that an estimated range cannot be made. Adds a requirement to disclose income (or loss) from continuing operations before income tax expense (or benefit) and income tax expense (or benefit) from continuing operations disaggregated between domestic and foreign. The ASU is effective for public business entities for fiscal years beginning on or after December 15, 2024, with early adoption permitted. The amendments in ASU 2023-09 should be applied on a prospective basis. Retrospective application is permitted. We are currently evaluating the impact of this ASU on our disclosures.

In November 2023, the FASB issued ASU 2023-07, “Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures” (“ASU 2023-07”), which improves reportable segment disclosure requirements, primarily through enhanced disclosures about significant segment expenses. The ASU is effective for public business entities for fiscal years beginning after December 15, 2023, and for interim reporting periods within fiscal years beginning after December 15, 2024. Early adoption is permitted. The amendments in ASU 2023-07 should be applied retrospectively to all prior periods presented in the financial statements. We are currently evaluating the impact of this ASU on our disclosures. The updated guidance is not expected to have a material impact to the Company’s consolidated financial statements or disclosures.

There were no other new accounting pronouncements issued or effective as of June 30, 2025 that had or are expected to have a material impact on our consolidated financial statements.

2. Long-Term Debt

Our finance lease liabilities and long-term debt consists of the following, in thousands:

Interest expense on finance lease liabilities and long-term debt was $6,000 and $108,000 for the three months ended June 30, 2025 and 2024, and $18,000 and $498,000 for thenine months ended June 30, 2025 and 2024, respectively.

Loan and Security Agreement

On January 17, 2023, we entered into a Loan and Security Agreement (the “Loan Agreement”) among Amtech, its U.S. based wholly owned subsidiaries Bruce Technologies, Inc., BTU International, Inc., Intersurface Dynamics, Incorporated, P.R. Hoffman Machine Products, Inc., and Entrepix, Inc., and UMB Bank, N.A., national banking association. The Loan Agreement provided for (i) a term loan (the “Term Loan”) in the amount of $12.0 million maturing January 17, 2028, and (ii) a revolving loan facility (the “Revolver”) with an availability of $8.0 million maturing January 17, 2024, each of which were secured by a first priority lien on substantially all of our assets. The recorded amount of the Term Loan had an interest rate of 6.38% and the Revolver had a floating per annum rate of interest equal to the Prime Rate, adjusted daily.

The Loan Agreement was fully repaid in the fourth quarter of 2024 and was subsequently terminated effective September 11, 2024. See the disclosure in our prior filings with the SEC for a discussion of the financial covenants that were in effect under the Loan Agreement, our failure to comply with the Debt to EBITDA and Fixed Charge Coverage Ratio covenants thereunder, and the Forbearance and Modification Agreement that we operated under prior to terminating this credit facility.

Finance Lease Obligations

Ourfinance lease obligations totaled $0.2 millionand $0.3 million as of June 30, 2025 and September 30, 2024, respectively.

The current and long-term portions of our finance leases are included in the current and long-term portions of finance lease liabilities and long-term debt in the table above and in our Condensed Consolidated Balance Sheets as of June 30, 2025 and September 30, 2024. See Note 5 for additional information.

3. Earnings Per Share

Basic earnings per share (“EPS”) is computed by dividing net income by the weighted average number of common shares outstanding for the period. Diluted EPS is computed similarly to basic EPS except that the denominator is increased to include the number of additional common shares that would have been outstanding if potentially dilutive common shares had been issued. Dilutive potential common shares include outstanding restricted stock units (“RSUs”) and stock options. In the case of a net loss, diluted earnings per share is calculated in the same manner as basic EPS.

For the three and nine months ended June 30, 2025, options for 929,490 and 956,480 weighted average shares, respectively, were excluded from the diluted EPS calculations because they were anti-dilutive. For the three and nine months ended June 30, 2024, options for 1,054,466 and 775,233 weighted average shares, respectively, were excluded from the diluted EPS calculations because they were anti-dilutive. These shares could become dilutive in the future.

A reconciliation of the components of the basic and diluted EPS calculations follows, in thousands, except per share amounts:

(1)

The number of common stock equivalents is calculated using the treasury method and the average market price during the period.

4. Inventories

The components of inventories are as follows, in thousands:

5. Leases

The following table provides information about the financial statement classification of our lease balances reported within the Condensed Consolidated Balance Sheets, in thousands:

The following table provides information about the financial statement classification of our lease expenses reported in the Condensed Consolidated Statements of Operations, in thousands:

Future minimum lease payments under non-cancelable leases as of June 30, 2025 are as follows, in thousands:

Operatinglease payments include $2.3 million related to options to extend lease terms that are reasonably certain of being exercised.

The following table provides information about the remaining lease terms and discount rates applied:

6. Goodwill and Intangible Assets

The Company accounts for goodwill at acquisition-date fair value and other finite intangibles at acquisition-date fair value less accumulated amortization. See Note 1 for a summary of the Company’s policies relating to goodwill and intangible assets.

Intangible Assets

The Company’s intangible assets, net consists of the following, in thousands:

The estimated aggregate amortization expense for each of the five succeeding fiscal years as of June 30, 2025 is as follows, in thousands:

The aggregate amortization expense during the three months ended June 30, 2025 and 2024 was $0.1 millionand$0.2 million, respectively. The aggregate amortization expense during the nine months ended June 30, 2025 and 2024 was $0.3 million and $0.7 million, respectively.

We review our intangible assets for impairment when events or circumstances indicate the carrying value may not be recoverable. For the period ended March 31, 2025, the Company lowered its guidance for the second quarter of fiscal year 2025 and reset projections for the rest of the year due to a prolonged weakness in the mature node semiconductor market driven by high inventory, tepid demand, and geopolitical tensions. As disclosed in the Goodwill section below, this resulted in a triggering event for impairment of goodwill. The results of the goodwill impairment test indicated that the book value of our Semiconductor Fabrication Solutions segment and Thermal Processing Solutions segment was in excess of fair value and was impaired. Prior to recognizing any impairment of goodwill, we tested the related long-lived assets for impairment in our Semiconductor Fabrication Solutions and Thermal Processing Solutions segments. We tested each identified asset group within each segment by first performing a recoverability test, comparing projected undiscounted cash flows from the use and eventual disposition of each asset group to its carrying value. This test indicated that the undiscounted cash flows were not sufficient to recover the carrying value of certain asset groups within our Semiconductor Fabrication Solutions segment. We then compared the carrying value of the individual long-lived assets within those asset groups against their fair value in order to determine if impairment existed. Determining the fair value of those asset groups involves the use of significant estimates and assumptions, including projections of revenues and expenses and related cash flows based on assumed long-term growth rates and demand trends, and estimated discount rates based on the asset group's weighted average return on assets, as derived from various methods. The fair value of the intangible assets was estimated using various valuation methodologies, including the multi-period excess earnings method and the relief from royalty method and the distributor method. These fair value measurements fall under Level 3 of the fair value hierarchy. As a result, we recorded a total impairment charge for intangible assets in our Semiconductor Fabrication Solutions segment of $2.6 million during the quarter ended March 31, 2025. The $2.6 million impairment consists of $1.8 million for customer relationships and $0.8 million for trade names primarily at Entrepix.

Atthe end of December 2023, we identified a triggering event. As a result of the decline in our stock price as of December 31, 2023, our book value materially exceeded our market value. As discussed in the Goodwill section below, this resulted in a triggering event for impairment of goodwill. The results of the goodwill impairment test indicated that the book value of our Semiconductor Fabrication Solutions reporting unit was in excess of the fair value, and, thus, was impaired. Prior to recognizing any impairment of goodwill, we tested the related long-lived assets for impairment in our Semiconductor Fabrication Solutions segment. We tested each identified asset group within our Semiconductor Fabrication Solutions segment by first performing a recoverability test, comparing projected undiscounted cash flows from the use and eventual disposition of each asset group to its carrying value. This test indicated that the undiscounted cash flows were not sufficient to recover the carrying value of certain asset groups. We then compared the carrying value of the individual long-lived assets within those asset groups against their fair value in order to determine if impairment existed. Determining the fair value of those asset groups involves the use of significant estimates and assumptions, including projections of revenues and expenses and related cash flows based on assumed long-term growth rates and demand trends, and estimated discount rates based on the asset group's weighted average return on assets, as derived from various methods. The fair value of the intangible assets were estimated using various valuation methodologies, including the multi-period excess earnings method, the relief from royalty method and the distributor method. These fair value measurements fall under Level 3 of the fair value hierarchy. As a result, we recorded a total impairment charge for intangible assets in our Semiconductor Fabrication

Solutions segment of $1.3 million during the quarter ended December 31, 2023. This impairment charge relates to developed technology, trade name, customer relationships and non-competition agreements at Entrepix.

Goodwill

The Company evaluates goodwill at the reporting unit level, which, for the Company, is at the level of the reportable segments, Thermal Processing Solutions and Semiconductor Fabrication Solutions. The changes in carrying amount of goodwill allocated to each of the reporting units for thenine months ended June 30, 2025 is as follows, in thousands:

On January 17, 2023, we acquired Entrepix, which has been integrated into our Semiconductor Fabrication Solutions segment. Under the purchase method of accounting, the purchase price for the acquisition was allocated to the tangible and identifiable intangible assets acquired and liabilities assumed based on their estimated fair values. The excess purchase price over fair value of net assets acquired of approximately $16.5 million was recorded as goodwill in the Semiconductor Fabrication Solutions segment. The primary driver for this acquisition was to add CMP and wafer cleaning equipment to our existing substrate polishing and wet process chemical offerings.

We review goodwill for impairment when events or circumstances indicate the carrying value may not be recoverable. For the period ended March 31, 2025, the Company lowered its guidance for the second quarter of fiscal year 2025 and reset projections for future periods due to prolonged weakness in the mature node semiconductor market driven by high inventory, tepid demand, and geopolitical tensions. This triggering event indicated a need to test goodwill for impairment. The goodwill impairment test indicated book value was in excess of fair value by $15.4 million for our Semiconductor Fabrication Solutions segment and $5.0 million for our Thermal Processing Solutions segment. As a result, we recorded a $20.4 million impairment charge in the period ended March 31, 2025.

At the end of December 2023, we identified a triggering event. As a result of the decline in our stock price as of December 31, 2023, our book value materially exceeded our market value leading to a $6.4 million impairment charge in fiscal 2024. This triggering event indicated a need to test goodwill for impairment. The goodwill impairment test indicated the book value of our Semiconductor Fabrication Solutions (formerly Material and Substrate) reporting unit was in excess of fair value. As a result, we recorded a $6.4 million impairment charge in the period ended December 31, 2023. There wasno goodwill impairment identified in our Thermal Processing Solutions (formerly Semiconductor) reporting unit.

Determining the fair value of a reporting unit involves the use of significant estimates and assumptions. Our goodwill impairment test uses a weighting of the income approach and the market approach to estimate a reporting unit’s fair value. The income approach is based on a discounted future cash flow analysis that uses certain assumptions including: projections of revenues and expenses and related cash flows based on assumed long-term growth rates and demand trends; expected future investments and working capital requirements to sustain and grow the business; and estimated discount rates based on the reporting unit’s weighted average cost of capital as derived by the Capital Asset Pricing Model and other methods, which includes observable market inputs and other data from identified comparable companies. The same estimates are also used internally for our capital budgeting process, and for long-term and short-term business planning and forecasting. We test the reasonableness of the inputs and outcomes of our discounted cash flow analysis against available comparable market data, and we also perform a reconciliation of our total market capitalization to the estimated fair value of all of our reporting units. The market approach is based on the application of appropriate market-derived multiples selected from (i) comparable publicly-traded companies and/or (ii) the implied transaction multiples derived from identified merger and acquisition activity in the market. Multiples are then selected based on a comparison of the reviewed data to that of the reporting unit and applied to relevant historical and forecasted financial parameters such as levels of revenues, EBITDA, EBIT or other metrics. The calculation of fair value falls under Level 3 of the fair value hierarchy.

If the future performance of these reporting units fall short of our expectations, if there are significant changes in operations due to changes in market conditions or if our stock price continues to decline, we could be required to recognize additional material impairment charges in future periods.

7. Income Taxes

Our effective tax rate was (5.1%)and (10.2%) for thenine months ended June 30, 2025 and 2024, respectively. The effective tax rate for the nine months ended June 30, 2025 differs from the U.S. statutory tax rate of 21% primarilydue to foreign income taxed at a foreign rate different than 21%, for permanent items, including the non-deductibility of the goodwill impairment, and changes in valuation allowances. For the three months ended June 30, 2025 and 2024, we recorded income tax expense of $0.8 million and $0.5 million, respectively. For thenine months ended June 30, 2025 and 2024, we recorded income tax expenseof $1.5 million and $0.7 million, respectively. The quarterly income tax provision is calculated using an estimated annual effective tax rate, based upon expected annual income, permanent items, statutory rates and planned tax strategies in the various jurisdictions in which we operate. However, losses in certain jurisdictions and discrete items are excluded from the determination of the estimated annual effective tax rate.

8. Equity and Stock-Based Compensation

Stock-based compensation expense was $0.3 million and $0.5 million in thethree months ended June 30, 2025 and 2024, respectively, and $1.0 millionand $1.2 million in thenine months ended June 30, 2025 and 2024, respectively. Stock-based compensation expense is included in selling, general and administrative expenses.

The following table summarizes our stock option activity during thenine months ended June 30, 2025:

The fair value of options was estimated at the applicable grant date using the Black-Scholes option pricing model with the following assumptions:

The following table summarizes our RSU activity during thenine months ended June 30, 2025:

9. Commitments and Contingencies

Purchase Obligations – As of June 30, 2025, we had unrecorded purchase obligations in the amount of $3.8 million. These purchase obligations consist of outstanding purchase orders for goods and services. While the amount represents purchase agreements, the actual amounts to be paid may be less in the event that any agreements are renegotiated, canceled or terminated.

Legal Proceedings and Other Claims – From time to time, we are a party to claims and actions for matters arising out of our business operations. We regularly evaluate the status of the legal proceedings and other claims in which we are involved to assess whether a loss is probable or there is a reasonable possibility that a loss, or an additional loss, may have been incurred and determine if accruals are appropriate. If accruals are not appropriate, we further evaluate each legal proceeding to assess whether an estimate of possible loss or range of possible loss can be made for disclosure. Although the outcome of claims and litigation is inherently unpredictable, we believe that we have adequate provisions for any probable and estimable losses. It is possible, nevertheless, that our consolidated financial position, results of operations or liquidity could be materially and adversely affected in any period by the resolution of a claim or legal proceeding. Legal expenses related to defense, negotiations, settlements, rulings and advice of outside legal counsel are expensed as incurred.

Employment Contracts– We have employment contracts and change in control agreements with, and severance plans covering, certain officers and management employees under which severance payments would become payable in the event of specified terminations without cause or terminations under certain circumstances after a change in control. If severance payments under the current employment contracts or severance plans were to become payable, the severance payments would generally range fromsixto twelve months of salary.

10. Reportable Segments

Amtech hastwo operating segments that are structured around the types of product offerings provided to our customers. In addition, the operating segments may be further distinguished by the Company’s respective brands. Thesetwo operating segments comprise ourtwo reportable segments discussed below. Ourtwo reportable segments are as follows:

Thermal Processing Solutions– We design, manufacture, sell and service thermal processing equipment and related controls for use by leading semiconductor manufacturers, and in electronics, automotive and other industries.

Semiconductor Fabrication Solutions– We produce consumables parts and services, and equipment for producing silicon carbide, silicon and gallium nitride wafers, optical components and a variety of crystalline materials.

Information concerning our reportable segments is as follows, in thousands:

• Non-segment related assets include cash, fixed assets, and other assets.

11. Major Customers and Foreign Sales

During the nine months ended June 30, 2025, one customer of both our Thermal Processing Solutions and Semiconductor Fabrication Solutions segments accounted for 11% of our net revenues. During the nine months ended June 30, 2024, one Thermal Processing Solutions segment customer represented 11%of our net revenues.

Our net revenues were from customers in the following geographic regions: