AXCELIS TECHNOLOGIES INC — Director's Dealing 2021

May 18, 2021

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: AXCELIS TECHNOLOGIES INC (ACLS)
CIK: 0001113232
Period of Report: 2021-05-15

Reporting Person: Low Russell (EVP, Engineering)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2021-05-15	Common Stock	F	1462	$38.16	Disposed	56251	Direct
2021-05-15	Common Stock	F	1399	$38.16	Disposed	54852	Direct
2021-05-16	Common Stock	F	902	$38.16	Disposed	53950	Direct
2021-05-17	Common Stock	F	1109	$38.16	Disposed	52841	Direct
2021-05-17	Common Stock	A	8160	$0.00	Acquired	61001	Direct
2021-05-17	Common Stock	A	8160	$0.00	Acquired	69161	Direct

Footnotes

F1: These shares were withheld by the Company to cover the tax withholding obligations of the executive on the vesting of restricted stock units.

F2: Represents the closing price of the common stock on the date of the tax withholding.

F3: Of the shares held after this first tax withholding forfeiture (and related vesting) on May 15, 2021, 32,078 were issuable on vesting of restricted stock units granted to the executive under the 2012 Equity Incentive Plan and are subject to forfeiture.

F4: Of the shares held after this second tax withholding forfeiture (and related vesting) on May 15, 2021, 28,924 were issuable on vesting of restricted stock units granted to the executive under the 2012 Equity Incentive Plan and are subject to forfeiture.

F5: Of the shares held after this tax withholding forfeiture (and related vesting) on May 16, 2021, 26,891 were issuable on vesting of restricted stock units granted to the executive under the 2012 Equity Incentive Plan and are subject to forfeiture.

F6: Of the shares held after this tax withholding forfeiture (and related vesting) on May 17, 2021, 24,391 were issuable on vesting of restricted stock units granted to the executive under the 2012 Equity Incentive Plan and are subject to forfeiture.

F7: These shares are issuable on vesting of restricted stock units granted under the Company's 2012 Equity Incentive Plan. Assuming continuation of employment, 25% of these restricted stock units will vest on each of May 17, 2022, May 17, 2023, May 17, 2024 and May 17, 2025.

F8: Of the shares held after this first grant on May 17, 2021, 32,551 were issuable on vesting of restricted stock units granted to the executive under the 2012 Equity Incentive Plan and are subject to forfeiture.

F9: In this grant under the Company's 2012 Equity Incentive Plan, the executive may earn shares of common stock, ranging from zero to 150% of the granted units. The shares are earned based on the achievement of 2021 performance goals. Assuming continuation of employment,50% of the earned shares will vest on each of February 28, 2022 and February 28, 2023. Unearned restricted stock units will forfeit on February 28, 2022.

F10: Of the shares held after this second grant on May 17, 2021, 40,711 were issuable on vesting of restricted stock units granted to the executive under the 2012 Equity Incentive Plan and are subject to forfeiture.