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: PUMA MARY G (Director, President and CEO)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2021-05-15	Common Stock	F	5050	$38.16	Disposed	374076	Direct
2021-05-15	Common Stock	F	4832	$38.16	Disposed	369244	Direct
2021-05-16	Common Stock	F	3607	$38.16	Disposed	365637	Direct
2021-05-17	Common Stock	F	3812	$38.16	Disposed	361825	Direct
2021-05-17	Common Stock	A	29144	$0.00	Acquired	390969	Direct
2021-05-17	Common Stock	A	29144	$0.00	Acquired	420113	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	6000	Indirect

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, 112,993 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, 102,098 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, 93,967 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, 85,373 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, 114,517 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, 143,661 were issuable on vesting of restricted stock units granted to the executive under the 2012 Equity Incentive Plan and are subject to forfeiture.