AXCELIS TECHNOLOGIES INC — Director's Dealing 2018

May 18, 2018

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: AXCELIS TECHNOLOGIES INC (ACLS)
CIK: 0001113232
Period of Report: 2018-05-16

Reporting Person: ALDEBORGH JOHN E (EVP, Customer Operations)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2018-05-16	Common Stock	F	1507	$22.40	Disposed	36364	Direct
2018-05-16	Common Stock	A	8131	$0.00	Acquired	44495	Direct
2018-05-16	Common Stock	A	8131	$0.00	Acquired	52626	Direct
2018-05-17	Common Stock	F	737	$22.40	Disposed	51889	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 on May 16, 2018.

F2: Represents the closing price on May 16, 2018.

F3: Of the shares held as of May 16, 2018, 20,227 were issuable on vesting of restricted stock units granted to the executive under the 2012 Equity Incentive Plan and are subject to forfeiture.

F4: 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 16, 2019, May 16, 2020, May 16, 2021 and May 16, 2022.

F5: Of the shares held as of May 16, 2018, 28,358 were issuable on vesting of restricted stock units granted to the executive under the 2012 Equity Incentive Plan and are subject to forfeiture.

F6: These shares are issuable on vesting of restricted stock units granted under the Company's 2012 Equity Incentive Plan. Assuming continuation of employment, up to 50% of these restricted stock units will vest on each of February 28, 2019 and February 28, 2020, based on performance vesting criteria. Unvested restricted stock units will forfeit on February 28, 2019.

F7: Of the shares held as of May 16, 2018, 36,489 were issuable on vesting of restricted stock units granted to the executive under the 2012 Equity Incentive Plan and are subject to forfeiture.

F8: These shares were withheld by the Company to cover the tax withholding obligations of the executive on the vesting of restricted stock units on May 17, 2018.

F9: Represents the closing price on May 17, 2018.

F10: Of the shares held as of May 17, 2018, 33,989 were issuable on vesting of restricted stock units granted to the executive under the 2012 Equity Incentive Plan and are subject to forfeiture.