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The shares issued to the executive on the vesting were reduced by a number of shares having a value equal to the executive's tax withholding obligation with respect to the vested restricted stock units."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F4","text":"Of the shares held after this vesting event on May 16, 2026, 12,578 were issuable on vesting of restricted stock units granted to the reporting person under the 2012 Equity Incentive Plan and are subject to forfeiture."}],"balance_after":15565,"source":{"system":"sec-edgar","filing":"0002101601-26-000010","document":"form4-05202026_050507.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1113232/000210160126000010/form4-05202026_050507.xml","form_type":"4"}},{"id":770415,"issuer":{"id":4152,"kind":"organization","name":"AXCELIS TECHNOLOGIES INC","symbol":"ACLS"},"owners":[{"id":41914,"kind":"person","name":"Mahoney Robert John","position":1,"cik":"0002101601","reported_name":"Mahoney Robert John","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EVP Global Operations"}}],"security":"Common Stock","published_at":"2026-05-20T21:05:11.000Z","date":"2026-05-18","kind":"tax_withholding","planned":false,"acquired":false,"shares":182,"price":146.24,"value":26615.68,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Represents the closing price of the common stock on the date of the tax withholding."},{"field":"acquired","element":"transactionAcquiredDisposedCode","label":"F1","text":"This forfeiture of shares for tax withholding purposes relates to the vesting on May 16, 2026 of service vesting restricted stock units granted to the executive in May 2022. The shares issued to the executive on the vesting were reduced by a number of shares having a value equal to the executive's tax withholding obligation with respect to the vested restricted stock units."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Of the shares held after this vesting event on May 16, 2026, 12,846 were issuable on vesting of restricted stock units granted to the reporting person under the 2012 Equity Incentive Plan and are subject to forfeiture."}],"balance_after":15695,"source":{"system":"sec-edgar","filing":"0002101601-26-000010","document":"form4-05202026_050507.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1113232/000210160126000010/form4-05202026_050507.xml","form_type":"4"}},{"id":772883,"issuer":{"id":4152,"kind":"organization","name":"AXCELIS TECHNOLOGIES INC","symbol":"ACLS"},"owners":[{"id":41914,"kind":"person","name":"Mahoney Robert John","position":1,"cik":"0002101601","reported_name":"Mahoney Robert John","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EVP Global Operations"}}],"security":"Common Stock","published_at":"2026-05-19T21:05:14.000Z","date":"2026-05-15","kind":"tax_withholding","planned":false,"acquired":false,"shares":61,"price":155.18,"value":9465.98,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F6","text":"Represents the closing price of the common stock on the date of the tax withholding."},{"field":"acquired","element":"transactionAcquiredDisposedCode","label":"F10","text":"This forfeiture of shares for tax withholding purposes relates to the vesting on May 15, 2026 of service vesting restricted stock units granted to the executive in May 2023. The shares issued to the executive on the vesting were reduced by a number of shares having a value equal to the executive's tax withholding obligation with respect to the vested restricted stock units."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F12","text":"Of the shares held after this vesting event on May 15, 2026, 13,221 were issuable on vesting of restricted stock units granted to the reporting person under the 2012 Equity Incentive Plan and are subject to forfeiture."}],"balance_after":15877,"source":{"system":"sec-edgar","filing":"0002101601-26-000008","document":"form4-05192026_050510.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":6,"url":"https://www.sec.gov/Archives/edgar/data/1113232/000210160126000008/form4-05192026_050510.xml","form_type":"4"}},{"id":772882,"issuer":{"id":4152,"kind":"organization","name":"AXCELIS TECHNOLOGIES INC","symbol":"ACLS"},"owners":[{"id":41914,"kind":"person","name":"Mahoney Robert John","position":1,"cik":"0002101601","reported_name":"Mahoney Robert John","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EVP Global Operations"}}],"security":"Common Stock","published_at":"2026-05-19T21:05:14.000Z","date":"2026-05-15","kind":"tax_withholding","planned":false,"acquired":false,"shares":170,"price":155.18,"value":26380.6,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F6","text":"Represents the closing price of the common stock on the date of the tax withholding."},{"field":"acquired","element":"transactionAcquiredDisposedCode","label":"F10","text":"This forfeiture of shares for tax withholding purposes relates to the vesting on May 15, 2026 of service vesting restricted stock units granted to the executive in May 2023. The shares issued to the executive on the vesting were reduced by a number of shares having a value equal to the executive's tax withholding obligation with respect to the vested restricted stock units."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F11","text":"Of the shares held after this vesting event on May 15, 2026, 13,346 were issuable on vesting of restricted stock units granted to the reporting person under the 2012 Equity Incentive Plan and are subject to forfeiture."}],"balance_after":15938,"source":{"system":"sec-edgar","filing":"0002101601-26-000008","document":"form4-05192026_050510.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":5,"url":"https://www.sec.gov/Archives/edgar/data/1113232/000210160126000008/form4-05192026_050510.xml","form_type":"4"}},{"id":772881,"issuer":{"id":4152,"kind":"organization","name":"AXCELIS TECHNOLOGIES INC","symbol":"ACLS"},"owners":[{"id":41914,"kind":"person","name":"Mahoney Robert John","position":1,"cik":"0002101601","reported_name":"Mahoney Robert John","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EVP Global Operations"}}],"security":"Common Stock","published_at":"2026-05-19T21:05:14.000Z","date":"2026-05-15","kind":"tax_withholding","planned":false,"acquired":false,"shares":173,"price":155.18,"value":26846.14,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F6","text":"Represents the closing price of the common stock on the date of the tax withholding."},{"field":"acquired","element":"transactionAcquiredDisposedCode","label":"F8","text":"This forfeiture of shares for tax withholding purposes relates to the vesting on May 15, 2026 of service vesting restricted stock units granted to the executive in May 2024. The shares issued to the executive on the vesting were reduced by a number of shares having a value equal to the executive's tax withholding obligation with respect to the vested restricted stock units."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F9","text":"Of the shares held after this vesting event on May 15, 2026, 13,696 were issuable on vesting of restricted stock units granted to the reporting person under the 2012 Equity Incentive Plan and are subject to forfeiture."}],"balance_after":16108,"source":{"system":"sec-edgar","filing":"0002101601-26-000008","document":"form4-05192026_050510.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":4,"url":"https://www.sec.gov/Archives/edgar/data/1113232/000210160126000008/form4-05192026_050510.xml","form_type":"4"}},{"id":772880,"issuer":{"id":4152,"kind":"organization","name":"AXCELIS TECHNOLOGIES INC","symbol":"ACLS"},"owners":[{"id":41914,"kind":"person","name":"Mahoney Robert John","position":1,"cik":"0002101601","reported_name":"Mahoney Robert John","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EVP Global Operations"}}],"security":"Common Stock","published_at":"2026-05-19T21:05:14.000Z","date":"2026-05-15","kind":"tax_withholding","planned":false,"acquired":false,"shares":372,"price":155.18,"value":57726.96,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F6","text":"Represents the closing price of the common stock on the date of the tax withholding."},{"field":"acquired","element":"transactionAcquiredDisposedCode","label":"F5","text":"This forfeiture of shares for tax withholding purposes relates to the vesting on May 15, 2026 of service vesting restricted stock units granted to the executive in May 2025. The shares issued to the executive on the vesting were reduced by a number of shares having a value equal to the executive's tax withholding obligation with respect to the vested restricted stock units."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F7","text":"Of the shares held after this vesting event on May 15, 2026, 14,052 were issuable on vesting of restricted stock units granted to the reporting person under the 2012 Equity Incentive Plan and are subject to forfeiture."}],"balance_after":16281,"source":{"system":"sec-edgar","filing":"0002101601-26-000008","document":"form4-05192026_050510.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1113232/000210160126000008/form4-05192026_050510.xml","form_type":"4"}},{"id":772879,"issuer":{"id":4152,"kind":"organization","name":"AXCELIS TECHNOLOGIES INC","symbol":"ACLS"},"owners":[{"id":41914,"kind":"person","name":"Mahoney Robert John","position":1,"cik":"0002101601","reported_name":"Mahoney Robert John","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EVP Global Operations"}}],"security":"Common Stock","published_at":"2026-05-19T21:05:14.000Z","date":"2026-05-15","kind":"grant","planned":false,"acquired":true,"shares":1947,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F3","text":"These shares are issuable on vesting of restricted stock units granted under the Company's 2012 Equity Incentive Plan on May 15, 2026. In this grant, the executive may earn shares of common stock, ranging from zero to 200% of the granted units. The shares are earned based on the achievement of performance goals based on relative total shareholder return over a performance period of January 1, 2026 to December 31, 2028. Assuming continuation of employment, 100% of the earned shares will vest on measurement of performance in 2029. Unearned restricted stock units will forfeit at such time."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F4","text":"Of the shares held after this grant on May 15, 2026, 14,821 shares were issuable on vesting of restricted stock units granted to the executive under the 2012 Equity Incentive Plan and are subject to forfeiture."}],"balance_after":16653,"source":{"system":"sec-edgar","filing":"0002101601-26-000008","document":"form4-05192026_050510.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1113232/000210160126000008/form4-05192026_050510.xml","form_type":"4"}},{"id":772878,"issuer":{"id":4152,"kind":"organization","name":"AXCELIS TECHNOLOGIES INC","symbol":"ACLS"},"owners":[{"id":41914,"kind":"person","name":"Mahoney Robert John","position":1,"cik":"0002101601","reported_name":"Mahoney Robert John","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EVP Global Operations"}}],"security":"Common Stock","published_at":"2026-05-19T21:05:14.000Z","date":"2026-05-15","kind":"grant","planned":false,"acquired":true,"shares":1947,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"These shares are issuable on vesting of restricted stock units granted under the Company's 2012 Equity Incentive Plan on May 15, 2026. Assuming continuation of employment, these restricted stock units will vest as to one-third of the shares granted on each of May 15, 2027, May 15, 2028, and May 15, 2029."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Of the shares held following this grant on May 15, 2026, 12,874 were issuable on vesting of restricted stock units granted to the executive under the 2012 Equity Incentive Plan and are subject to forfeiture."}],"balance_after":14706,"source":{"system":"sec-edgar","filing":"0002101601-26-000008","document":"form4-05192026_050510.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1113232/000210160126000008/form4-05192026_050510.xml","form_type":"4"}},{"id":781238,"issuer":{"id":4152,"kind":"organization","name":"AXCELIS TECHNOLOGIES INC","symbol":"ACLS"},"owners":[{"id":41914,"kind":"person","name":"Mahoney Robert John","position":1,"cik":"0002101601","reported_name":"Mahoney Robert John","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EVP Global Operations"}}],"security":"Common Stock","published_at":"2026-05-13T21:05:06.000Z","date":"2026-05-12","kind":"sale","planned":false,"acquired":false,"shares":2258,"price":161,"value":363538.0,"ownership":{"direct":true},"footnotes":[{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F1","text":"Of the shares held after this sale on May 12, 2026, 10,927 shares were issuable on vesting of restricted stock units granted to the reporting person under the 2012 Equity Incentive Plan and are subject to forfeiture. This amount includes restricted stock units earned by the reporting person upon the achievement of 112.5% of the restricted stock units granted in 2025 based upon the achievement of 2025 performance goals."}],"balance_after":12759,"source":{"system":"sec-edgar","filing":"0002101601-26-000006","document":"form4-05132026_050501.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1113232/000210160126000006/form4-05132026_050501.xml","form_type":"4"}},{"id":869606,"issuer":{"id":4152,"kind":"organization","name":"AXCELIS TECHNOLOGIES INC","symbol":"ACLS"},"owners":[{"id":41914,"kind":"person","name":"Mahoney Robert John","position":1,"cik":"0002101601","reported_name":"Mahoney Robert John","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EVP Global Operations"}}],"security":"Common Stock","published_at":"2026-03-03T22:05:22.000Z","date":"2026-03-02","kind":"tax_withholding","planned":false,"acquired":false,"shares":573,"price":86.58,"value":49610.34,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F2","text":"Represents the closing price of the Company's common stock on March 2, 2026, the date of the tax withholding."},{"field":"acquired","element":"transactionAcquiredDisposedCode","label":"F1","text":"This forfeiture of shares for tax withholding purposes relates to the vesting on February 28, 2026 of performance-based restricted stock units (\"2024 PRSUs\") granted to the executive in May 2024. Of the 2024 PRSUs granted, 150% were determined to be earned by the executive pursuant to a resolution of the Axcelis Technologies, Inc. Compensation Committee on February 13, 2025, with half of the earned shares vesting on February 28, 2025 and the remaining half of the earned shares vesting on February 28, 2026. The shares issued to the executive on the vesting were reduced by a number of shares having a value equal to the executive's tax withholding obligation with respect to the vested 2024 PRSUs."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F3","text":"Of the shares held after the vesting of the remaining 2024 PRSUs, 10,543 were issuable on vesting of restricted stock units granted to the reporting person under the 2012 Equity Incentive Plan and are subject to forfeiture."}],"balance_after":14633,"source":{"system":"sec-edgar","filing":"0002101601-26-000004","document":"form4-03032026_050312.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1113232/000210160126000004/form4-03032026_050312.xml","form_type":"4"}},{"id":937625,"issuer":{"id":4152,"kind":"organization","name":"AXCELIS TECHNOLOGIES INC","symbol":"ACLS"},"owners":[{"id":41914,"kind":"person","name":"Mahoney Robert John","position":1,"cik":"0002101601","reported_name":"Mahoney Robert John","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"EVP Global Operations"}}],"security":"Common Stock","published_at":"2026-01-16T22:05:05.000Z","date":"2026-01-15","kind":"grant","planned":false,"acquired":true,"shares":1734,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"price","element":"transactionPricePerShare","label":"F1","text":"These shares are issuable on vesting of restricted stock units granted under the Company's 2012 Equity Incentive Plan on January 15, 2026. Assuming continuation of employment, these restricted stock units will vest as to 25% of the shares granted on each of January 15, 2027, January 15, 2028, January 15, 2029, and January 15, 2030."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Of the shares held after this grant on January 15, 2026, 11,611 were issuable on vesting of restricted stock units granted to the executive under the 2012 Equity Incentive Plan and are subject to forfeiture."}],"balance_after":15206,"source":{"system":"sec-edgar","filing":"0002101601-26-000002","document":"form4-01162026_050101.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1113232/000210160126000002/form4-01162026_050101.xml","form_type":"4"}}]}