ENTEGRIS INC

Report of Independent Registered Public Accounting Firm

To the Stockholders and Board of Directors

Entegris, Inc.:

Opinion on the Consolidated Financial Statements

We have audited the accompanying consolidated balance sheets of Entegris, Inc. and subsidiaries (the Company) as of December 31, 2023 and 2022, the related consolidated statements of operations, comprehensive income, equity, and cash flows for each of the years in the three-year period ended December 31, 2023, and the related notes (collectively, the consolidated financial statements). In our opinion, the consolidated financial statements present fairly, in all material respects, the financial position of the Company as of December 31, 2023 and 2022, and the results of its operations and its cash flows for each of the years in the three-year period ended December 31, 2023, in conformity with U.S. generally accepted accounting principles.

Basis for Opinion

These consolidated financial statements are the responsibility of the Company’s management. Our responsibility is to express an opinion on these consolidated financial statements based on our audit. We are a public accounting firm registered with the PCAOB and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audit in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud. Our audit included performing procedures to assess the risks of material misstatement of the consolidated financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated financial statements. Our audit also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. We believe that our audit provides a reasonable basis for our opinion.

Critical Audit Matter

The critical audit matter communicated below is a matter arising from the current period audit of the consolidated financial statements that was communicated or required to be communicated to the audit committee and that: (1) relates to accounts or disclosures that are material to the consolidated financial statements and (2) involved our especially challenging, subjective, or complex judgments. The communication of a critical audit matter does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matter below, providing a separate opinion on the critical audit matter or on the accounts or disclosures to which it relates.

Goodwill impairment evaluation for APS reporting unit prior to segment realignment

As discussed in Note 10 to the consolidated financial statements, the goodwill balance as of December 31, 2023 was $3,945.9 million, of which $3,631.3 million related to the Materials Solutions (MS) reportable segment. The MS reportable segment was the result of the realignment in the third quarter of 2023 combining the Advanced Planarization Solutions (APS) reportable segment and the Specialty Chemicals and Engineered Materials (SCEM) reportable segment. Prior to the realignment, the APS reportable segment was aligned to the APS reporting unit. The Company performs goodwill impairment testing on an annual basis and whenever events or changes in circumstances indicate that the carrying value of a reporting unit exceeds its fair value. The realignment was identified as a triggering event related to the APS reporting unit. In determining the fair value of the APS reporting unit the Company utilized a discounted cash flow model and certain market information.

We identified the goodwill impairment evaluation for the APS reporting unit prior to the segment realignment as a critical audit matter. We performed sensitivity analysis to determine the significant assumptions in the valuation of the goodwill. A high degree of subjective auditor judgment was required to evaluate the Company’s estimates of future revenue growth rates used in the discounted cash flow model. Specifically, the revenue growth rates used to estimate the fair value of the reporting unit were challenging to evaluate as they involved subjective assessments of future market and economic conditions that were sensitive to variation. Minor changes in the revenue growth rates could have had a significant impact on the fair value.

The following are the primary procedures we performed to address this critical audit matter. We evaluated the design and tested the operating effectiveness of certain internal controls related to the Company’s goodwill impairment process. This included the control related to the Company’s estimates of the future revenue growth rates used to determine the fair value of the APS reporting unit. We evaluated the Company’s forecasted revenue growth rates for the APS reporting unit by comparing them to forecasted future growth rates in the Company’s and its peer companies’ analyst reports and industry reports. In addition, we compared the Company’s historical revenue forecasts to actual results to assess the Company’s ability to accurately forecast.

/s/ KPMG LLP

We or our predecessor firms have served as the Company’s auditor since 1966.

Minneapolis, Minnesota

February 14, 2024