AXCELIS TECHNOLOGIES INC — Director's Dealing 2017

May 17, 2017

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: AXCELIS TECHNOLOGIES INC (ACLS)
CIK: 0001113232
Period of Report: 2017-05-17

Reporting Person: Low Russell (EVP, Engineering)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2017-05-17	Common Stock	A	10000	$0.00	Acquired	20949	Direct
2017-05-17	Common Stock	A	3333	$0.00	Acquired	24282	Direct

Footnotes

F1: 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 May 17, 2018, May 17, 2019, May 17, 2020 and May 17, 2021. The executive has agreed that a number of shares, having a value equal to the required tax withholding at vesting, will be withheld from the shares issued on each vest date.

F2: Of the shares held immediately prior to May 17, 2017 10,949 were issuable on vesting of restricted stock units granted under the 2012 Equity Incentive Plan and are subject to forfeiture.

F3: These shares are issuable on vesting of restricted stock units granted under the Company's 2012 Equity Incentive Plan. Assuming continuation of employment, some or all of these restricted stock units will vest on February 28, 2018 based on performance vesting criteria. Unvested restricted stock units will forfeit on that date. The executive has agreed that a number of shares, having a value equal to the required tax withholding at vesting, will be withheld from the shares issued on the vest date.

F4: Of the shares held as of May 17, 2017, 24,282 were issuable on vesting of restricted stock units granted to the executive under the 2012 Equity Incentive Plan and are subject to forfeiture.