Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
ALDEBORGH JOHN E
  2. Issuer Name and Ticker or Trading Symbol
AXCELIS TECHNOLOGIES INC [ACLS]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
EVP, Customer Operations
(Last)
(First)
(Middle)
108 CHERRY HILL DRIVE
3. Date of Earliest Transaction (Month/Day/Year)
05/16/2018
(Street)

BEVERLY, MA 01915
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock 05/16/2018   F   1,507 D (1) $ 22.4 (2) 36,364 (3) D  
Common Stock 05/16/2018   A   8,131 A $ 0 (4) 44,495 (5) D  
Common Stock 05/16/2018   A   8,131 A $ 0 (6) 52,626 (7) D  
Common Stock 05/17/2018   F   737 D (8) $ 22.4 (9) 51,889 (10) D  

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
ALDEBORGH JOHN E
108 CHERRY HILL DRIVE
BEVERLY, MA 01915
      EVP, Customer Operations  

Signatures

 Lynnette C. Fallon, as attorney in fact for John E. Aldeborgh   05/17/2018
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) 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.
(2) Represents the closing price on May 16, 2018.
(3) 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.
(4) 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.
(5) 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.
(6) 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.
(7) 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.
(8) 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.
(9) Represents the closing price on May 17, 2018.
(10) 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.

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