Exhibit 10.4  GT SOLAR INTERNATIONAL, INC.  RESTRICTED STOCK UNIT AGREEMENT  THIS RESTRICTED STOCK UNIT AGREEMENT (this Agreement)
is made as of September 12, 2008, by and between GT Solar International, Inc.,
a Delaware corporation (the Company), and Matthew E. Massengill (Director),
in accordance with the 2008 Equity Incentive Plan of the Company, as the same
may be amended from time to time (the Plan).  The Company and Director desire to enter into an
agreement pursuant to which the Company shall grant to Director seventeen
thousand (17,000) restricted stock units (the RSUs) under the
Plan.  Each RSU shall entitle Director to
receive from the Company one share of the Companys common stock, par value
$.01 per share (Common Stock) for each RSU granted hereunder that
becomes vested under the terms described herein and in the Plan.  All of such shares of Common Stock that may
hereafter be delivered to Director pursuant to this Agreement are referred to
herein as Director Stock.  The
issuance of shares of the Director Stock to Director hereunder is intended to
be exempt from registration under the Securities Act of 1933 pursuant to Rule 701
thereunder.  Certain definitions are set
forth in Section 7 of this Agreement.  The parties hereto agree as follows:  1.Incorporation
by Reference; Plan Document Receipt. 
This Agreement is subject in all respects to the terms and provisions of
the Plan (including, without limitation, any amendments thereto adopted at any
time and from time to time unless such amendments are expressly intended not to
apply to the award provided hereunder), all of which terms and provisions are
made a part of and incorporated in this Agreement as if they were expressly set
forth herein.  Any capitalized term not
defined in this Agreement shall have the same meaning as is ascribed thereto in
the Plan.  Director hereby acknowledges
receipt of a true copy of the Plan and that Director has read the Plan
carefully and fully understands its content. 
In the event of a conflict between the terms of this Agreement and the
terms of the Plan, the terms of the Plan shall control.  2.Grant
of the RSUs.  (a)The
Company hereby grants to Director, as of the date hereof, 17,000RSUs, subject to the terms and conditions
hereunder.  Director agrees and
understands that nothing contained in this Agreement provides, or is intended
to provide, Director with any protection against potential future dilution of
Directors stockholder interest in the Company for any reason.  Director shall not have the rights of a
stockholder in respect of the shares of Common Stock underlying these RSUs
until such Common Stock is delivered to the Participant in accordance with Section 4.  (b)The
grant of the RSUs by the Company is subject to Directors execution and delivery
of the attached Confidentiality Agreement between Director and the Company (or,
at the discretion of the Board, a similar agreement containing such terms as
the Board, or a duly


designated
committee thereof, shall determine) (the Director Confidentiality Agreement)
and these RSUs and all shares of the Director Stock shall be subject to the
terms and conditions of the Director Confidentiality Agreement.  (c)In
connection with the receipt of the RSUs and the delivery of any Director Stock
hereunder, Director represents and warrants to, and agrees with, the Company
that:  (i)The
RSUs and the Director Stock to be acquired by Director pursuant to this
Agreement shall be acquired for Directors own account and not with a view to,
or intention of, distribution thereof in violation of the Securities Act, or
any applicable state securities laws, and the RSUs and the Director Stock shall
not be disposed of in contravention of the Securities Act or any applicable
state securities laws.  (ii)This
Agreement constitutes the legal, valid and binding obligation of Director,
enforceable in accordance with its terms, and the execution, delivery and
performance of this Agreement by Director do not and shall not conflict with,
violate or cause a breach of any agreement, contract or instrument to which
Director is a party or any judgment, order or decree to which Director is
subject.  (iii)Director has not taken
any action that constitutes a conflict with, violation or breach of, and the
execution and delivery of this Agreement and the other agreements contemplated
hereby will not conflict with, violate or cause a breach of, any noncompete,
nonsolicitation or confidentiality agreement to which Director is a party or by
which Director is bound.  Director agrees
to notify the Board of any matter (including, but not limited to, any potential
acquisition by the Company) which, to Directors knowledge, might reasonably be
expected to violate or cause a breach of any such agreement.  (iv)Director
is a resident of the State of California.  (v)Director
has been advised and encouraged in writing (via this Agreement) to consult with
an attorney and a tax advisor prior to signing this Agreement.  (d)As
an inducement to the Company to issue any RSUs to Director, and as a condition
thereto, Director acknowledges and agrees that neither the issuance of the RSUs
or the delivery of any Director Stock nor any provision contained herein shall
entitle Director to a directorship on the Board and/or on the board of
directors of the Subsidiaries, or affect the right of the Company to terminate
Directors directorship at any time, with or without cause.  (e)The
Company and Director acknowledge and agree that this Agreement has been
executed and delivered, the RSUs have been granted and any Director Stock that
may be delivered hereunder will be delivered, in connection with and as a part
of the compensation and incentive arrangements between the Company and
Director.  (f)In
connection with the issuance of any Director Stock hereunder, Director hereby
agrees and acknowledges that all of the shares of the Director Stock are
subject in all respects to the terms of this Agreement.  2


3.Vesting.  (a)Except
as otherwise provided in this Section 3, the RSUs shall become
vested in accordance with the following schedule, if as of each such date
Director has continuously served as a director on the Board and/or on the board
of directors of the Subsidiaries since the date hereof, such that, subject to
the other terms and conditions of this Agreement, all of the RSUs shall be
vested on September 12, 2010:  Date
  
  Portion of RSUs VestedSeptember 12, 2009
  
  8,500 RSUsSeptember 12, 2010
  
  Additional 8,500
  RSUs  (b)Except
as otherwise provided in this Section 3, if Directors directorship
with the Company and/or its Subsidiaries terminates for any reason (including
upon the death or disability of Director prior to the vesting of all or any
portion of the RSUs awarded under this Agreement), such unvested portion of the
RSUs shall immediately be cancelled and Director (and Directors estate,
designated beneficiary or other legal representative) shall forfeit any rights
or interests in and with respect to any such RSUs.  (c)In
addition to Sections 3(a)-(b) above, upon a termination of Directors
directorship with the Company that also constitutes a separation from service
within the meaning of Treas. Reg. § 1.409A-3(i)(5) within twelve
months following a Change in Control, as defined below, of the Company (the Change
in Control Termination), the RSUs shall vest as follows: (A) if the
Change in Control Termination occurs on or before September 12, 2009,
8,500 RSUs shall vest on the date of the Change in Control Termination and (B) if
the Change in Control Termination occurs on any date from September 13,
2009 up to and including September 12, 2010, the remaining 8,500 RSUs
shall vest.  For purposes of this
Agreement, (x) the term Change in Control means (i) the
consummation of any transaction or series of transactions resulting in a Third
Party (or group of affiliated third parties) owning, directly or indirectly,
securities of the Company possessing the voting power to elect a majority of
the members of the Board (whether by merger, consolidation or sale or transfer
of the Companys securities) or (ii) the sale, transfer or other
disposition of all or substantially all of the business and assets of the
Company, whether by sale of assets, merger or otherwise (determined on a
consolidated basis) to a Third Party (or group of affiliated third parties),
and (y) the term Third Party means any person or entity who or
which (i) does not own any of the Companys securities as of the date of
this Agreement, (ii) is not controlling, controlled by or under common control
with any person or entity that owns any of the Companys securities as of the
date of this Agreement and (iii) is not the spouse or descendent (by birth
or adoption) of any person who directly or indirectly owns or controls any of
the Companys securities as of the date of this Agreement.  Upon the occurrence of a Change in Control
Termination in the time period described in either clause (A) or (B) of
the first sentence of this Section 3(c), the Board shall be
permitted, in its sole discretion, to cause the Company to pay to Director in
substitution for the vesting of Directors RSUs and the delivery of Common
Stock to Director under such circumstances and in respect of each share of
Common Stock that would otherwise be issuable upon such vesting, cash in an
amount per share of Common Stock equal to the price per share payable in the
Change in Control in respect of each issued and outstanding share of Common
Stock.  3


4.Delivery
of Common Stock.  Subject to the
terms of the Plan, if the RSUs awarded by this Agreement become vested, the
Company shall promptly distribute to Director the number of shares of Common
Stock equal to the number of the RSUs that so vested; provided that to
the extent required by Section 409A of the Code, delivery of shares of
Common Stock upon a Participants separation from service within the meaning
of Treas. Reg. § 1.409A-1 shall be
deferred until the six month anniversary of such separation from service.  In connection with the delivery of the shares
of Common Stock pursuant to this Agreement, the Participant agrees to execute
any documents reasonably requested by the Company and provide therein customary
representations and warranties related to the receipt of such shares of Common
Stock.  5.Certificates.  The shares of Director Stock may be in
certificated or uncertificated form, as permitted by the Companys Bylaws.  Prior to any registered public offering of
any Common Stock, the Company shall hold each certificate representing the
Director Stock (or shall reflect in its records the uncertificated Director
Stock as being held by the Company) until such time as such Director Stock is
transferred by Director, other than to a trust that at all times remains solely
for the exclusive benefit of one or more of Directors spouse and lineal
descendants (whether natural or adopted), in compliance with applicable laws
and any agreement imposing restrictions on the transfer of Director Stock.  6.Restructuring
Event.  In the event of a stock
dividend, stock split or recapitalization or a corporate reorganization in
which the Company is a surviving corporation, including without limitation a
merger, consolidation, split-up or spin-off or a liquidation or distribution of
securities or assets other than cash dividends (a Restructuring Event),
the number of shares of the Director Stock held by Director may be adjusted by
the Board, or a duly designated committee thereof, as it reasonably determines
is necessary to reflect such Restructuring Event.  7.Definitions.  Board means the Companys Board of Directors.  Securities Act means the Securities Act of
1933, as amended from time to time, and the rules and regulations
promulgated thereunder.  Subsidiary means any corporation of which the
Company owns securities having a majority of the ordinary voting power in
electing the board of directors directly or through one or more subsidiaries.  8.Notices.  Any notice provided for in this Agreement
must be in writing and must be either personally delivered, mailed by first
class mail (postage prepaid and return receipt requested) or sent by reputable
overnight courier service (charges prepaid) to the recipient at the address
below indicated:  4


To the Company:  GT Solar International, Inc. 243 Daniel Webster Highway Merrimack, New Hampshire 03054 Attention: General Counsel  To Director:  Matthew E. Massengill 3 Upper Vintage Laguna Niguel, CA 92677-9202  or such other address or to the attention of such
other person as the recipient party shall have specified by prior written
notice to the sending party.  Any notice
under this Agreement shall be deemed to have been given when so delivered or
sent or, if mailed, five days after deposit in the U.S. mail.  9.General
Provisions.  (a)Transferability.  The RSUs shall not be transferable by
Director other than by the laws of will or descent.  All provisions of this Agreement shall in any
event continue to apply to any RSU transferred as permitted by this Section 9(a),
and any transferee shall be bound by all provisions of this Agreement as and to
the same extent as Director.  Any
transfer or attempted transfer of any RSUs in violation of any provision of
this Agreement shall be void, and the Company shall not record such transfer on
its books or treat any purported transferee of such RSUs as the owner of such
stock for any purpose.  (b)Withholding
Taxes.  The Company shall be entitled
to withhold from any amounts due and payable by the Company to Director the
amount of any federal, state, local or other tax which, in the opinion of the
Company, is required to be withheld in connection with the vesting of the RSUs
or the delivery of shares of the Director Stock.  To the extent that the amounts available to
the Company for such withholding are insufficient, it shall be a condition to
the delivery or vesting, as applicable, of such shares of the Director Stock
that Director make arrangements satisfactory to the Company for the payment of
the balance of such taxes required to be withheld.  The Board, upon the written request of
Director, in the Boards sole discretion and pursuant to such procedures as it
may specify from time to time, may permit Director to satisfy all or part of
the tax obligations in connection with the vesting of the RSUs or the delivery
of the shares of Director Stock by (a) having the Company withhold
otherwise deliverable shares, or (b) delivering to the Company
already-owned shares, in each case having a Fair Market Value (as defined in
the Plan) equal to the amount sufficient to satisfy such tax obligations,
provided such shares have been held by Director for at least six months.  (c)Severability.  Whenever possible, each provision of this
Agreement shall be interpreted in such manner as to be effective and valid
under applicable law, but if any provision of this Agreement is held to be
invalid, illegal or unenforceable in any respect under any applicable law or rule in
any jurisdiction, such invalidity, illegality or unenforceability shall not
affect any other provision or any other jurisdiction, but this Agreement shall
be reformed,  5


construed and
enforced in such jurisdiction as if such invalid, illegal or unenforceable
provision had never been contained herein.  (d)Complete
Agreement.  This Agreement, the Plan,
those documents expressly referred to herein and therein and other documents of
even date herewith embody the complete agreement and understanding among the
parties and supersede and preempt any prior understandings, agreements or
representations by or among the parties, written or oral, which may have
related to the subject matter hereof in any way.  (e)Counterparts.  This Agreement may be executed in separate
counterparts, each of which is deemed to be an original and all of which taken
together constitute one and the same agreement.  (f)Successors
and Assigns.  Except as otherwise
provided herein, this Agreement shall bind and inure to the benefit of and be
enforceable by Director, the Company and their respective successors and
assigns (including subsequent permitted holders of the RSUs or the Director
Stock); provided that the rights and obligations of Director under this
Agreement shall not be assignable except in connection with a permitted
transfer of the Director Stock hereunder.  (g)Choice
of Law.  All questions concerning the
construction, validity, enforcement and interpretation of this Agreement and
the exhibits hereto shall be governed by, and construed in accordance with, the
internal law, and not the law of conflicts, of the State of Delaware, without
giving effect to any choice of law or conflict of law rules or provisions
(whether of the State of Delaware or any other jurisdiction) that would cause
the application of the laws of any jurisdiction other than the State of
Delaware.  (h)Remedies.  Each of the parties to this Agreement shall
be entitled to enforce its rights under this Agreement specifically, to recover
damages and costs (including reasonable attorneys fees) caused by any breach
of any provision of this Agreement and to exercise all other rights existing in
its favor.  The parties hereto agree and
acknowledge that money damages would not be an adequate remedy for any breach
of the provisions of this Agreement and that any party shall be entitled to
specific performance and/or other injunctive relief from any court of law or
equity of competent jurisdiction (without posting any bond or deposit) in order
to enforce or prevent any violations of the provisions of this Agreement.  (i)Amendment
and Waiver.  The provisions of this
Agreement may be amended and waived only with the prior written consent of the
Company and Director.  *      *      *     
*  6


IN WITNESS WHEREOF, the parties hereto have executed
this Restricted Stock Unit Agreement on the date first written above.  GT SOLAR INTERNATIONAL, INC.By:
  /s/Edwin L. LewisName:
  Edwin L. LewisTitle:
  Vice President and General Counsel/s/ Matthew E. MassengillMatthew E. Massengill  [Signature Page - Restricted
Stock Unit Agreement with Massengill]