JOINDER TO THE CREDIT AGREEMENT

Exhibit 10.1

EXECUTION VERSION

JOINDER TO THE
CREDIT AGREEMENT

Dated as of June 15, 2012

JOINDER TO THE CREDIT AGREEMENT among GTAT CORPORATION, a Delaware corporation (the “U.S. Borrower”), GT ADVANCED TECHNOLOGIES LIMITED, a company incorporated under the laws of Hong Kong (the “Hong Kong Borrower”), GT ADVANCED TECHNOLOGIES INC., a Delaware corporation (“Holdings”), the banks, financial institutions and other institutional lenders parties to the Credit Agreement referred to below (collectively, the “Lenders”) and BANK OF AMERICA, N.A., as agent (the “Agent”) for the Lenders.

PRELIMINARY STATEMENTS:

(1)           The Borrowers, the Lenders and the Agent have entered into a Credit Agreement dated as of January 31, 2012 (as amended, restated, supplemented or otherwise modified through the date hereof, the “Credit Agreement”).  Capitalized terms not otherwise defined in this Joinder have the same meanings as specified in the Credit Agreement.

(2)           The U.S. Borrower has requested that the Additional Term Lenders (as defined below) provide to the U.S. Borrower Additional Term Loans (as defined below) pursuant to Section 2.13 of the Credit Agreement on the Additional Term Loan Effective Date (as defined below) and on the effective date of any subsequent Incremental Joinder Supplement (as defined below), in an aggregate principal amount on the Additional Term Loan Effective Date of $30,000,000 plus additional amounts pursuant to Incremental Joinder Supplements not to exceed an additional $45,000,000 in the aggregate, having substantially identical terms with, and having the same rights and obligations under the Credit Agreement as, the outstanding Term Loans.

SECTION 1.           The Credit Agreement is, effective as of the date hereof  and subject to the satisfaction of the conditions precedent set forth in Section 3, hereby amended as follows:

(a)           Section 1.01 of the Credit Agreement is hereby amended by inserting the following defined terms in the appropriate alphabetical positions:

“Additional Term Borrowing” means a borrowing pursuant to Section 2.01(a)(ii) consisting of Additional Term Loans of the same Type made by the Additional Term Lenders and, in the case of Eurodollar Rate Loans, having the same Interest Period.

“Additional Term Commitment” means, as to each Additional Term Lender, its obligation to make Additional Term Loans pursuant to Section 2.01(a)(ii) in an aggregate principal amount not to exceed (a) in the case of each Additional Term Lender that is an Additional Term Lender on the Additional Term Loan Effective Date, the amount set forth opposite such Lender’s name on Schedule 2.01(a)(ii) under the caption “Additional Term Commitment” in respect of such Additional Term Borrowing and (b) in the case of any Additional Term Lender that becomes a Additional Term Lender after the Additional Term Loan Effective Date, the amount specified (i) in any Incremental Joinder Supplement or (ii) in the Assignment and Acceptance pursuant to which such Additional Term Lender becomes a party hereto, as applicable, as such amount may be adjusted from time to time in accordance with this Agreement.

“Additional Term Facility” means, at any time, (a) on or prior to the Additional Term Loan Effective Date or the effective date of any Incremental Joinder Supplement, the aggregate amount of the Additional Term Commitments at such time and (b) thereafter, the aggregate principal amount of the Additional Term Loans of all Additional Term Lenders outstanding at such time. For the avoidance of doubt, any Additional Term Facility shall constitute a portion of the Term Loan Facility hereunder.

“Additional Term Lender” means, at any time, any Lender that has an Additional Term Commitment or an Additional Term Loan at such time.

“Additional Term Loan” means a Loan made pursuant to Section 2.01(a)(ii).  For the avoidance of doubt, each Additional Term Loan shall constitute a Term Loan hereunder.

“Additional Term Loan Effective Date” means the date of satisfaction of the conditions precedent to effectiveness set forth in Section 3 of Joinder No. 1 to this Agreement.

“Joinder No. 1” means the Joinder to this Agreement, dated as of June     , 2012, among Holdings, each Borrower, the Additional Term Lenders party thereto and the Administrative Agent.

“Incremental Joinder Supplement” means a Supplement to Joinder No. 1 executed by one or more Additional Term Lenders, Holdings, each Borrower and the Administrative Agent pursuant to which an Additional Term Lender agrees to make Additional Term Loans pursuant to Section 2.01(a)(ii) on identical terms to those contemplated for the Additional Term Loans made under Joinder No. 1 (and which will provide for an updated, replacement schedule to the one set forth in Section 2.07(a) reflecting the addition of such Additional Term Loans made pursuant to such Incremental Joinder Supplement).

(b)           Section 1.01 of the Credit Agreement is further amended as follows:

(i)             The definition of “Facility” is amended by inserting at the end thereof immediately after the period the following sentence: “For the avoidance of doubt, any Additional Term Facility shall constitute a portion of the Term Loan Facility hereunder.”

(ii)            The definition of “Loan Documents” is amended by inserting at the end thereof immediately before the period the phrase “(l) Joinder No. 1 and (m) each Incremental Joinder Supplement”.

(iii)           The definition of “Term Borrowing” is amended by inserting at the end thereof immediately after the period the following sentence: “For the avoidance of doubt, any Additional Term Borrowing shall constitute a Term Borrowing hereunder.”

(iv)           The definition of “Term Lender” is amended by inserting after the phrase “holds Term Loans at such time” the following: “and (c) any Additional Term Lender”.

(v)            The definition of “Term Loan” is amended by inserting at the end thereof immediately before the period the phrase “or any Additional Term Facility.”

(c)           Section 2.01(a) of the Credit Agreement is hereby amended by inserting the number “(i)” in front of the heading “The Term Borrowing” and inserting the following clause (ii) at the end of such Section to read as follows:

(i)            (ii) Additional Term Borrowings.  Subject to the terms and conditions set forth herein, (a) each Additional Term Lender that is an Additional Term Lender on the Additional Term Loan Effective Date severally agrees to make a single loan in Dollars to the U.S. Borrower on the Additional Term Loan Effective Date in an amount not to exceed such Additional Term Lender’s Additional Term Commitment; and  (b) any Additional Term Lender that becomes an Additional Term Lender after the Additional Term Loan Effective Date agrees to make a loan in Dollars to the U.S. Borrower on the date specified in the Incremental Joinder Supplement executed by such Lender in an amount not to exceed such Additional Term Lender’s Additional Term Commitment. Each Additional Term Borrowing shall consist of Additional Term Loans made by the Additional Term Lenders in accordance with the prior sentence.  Amounts borrowed under this Section 2.01(a)(ii) and repaid or prepaid may not be reborrowed.  Additional Term Loans may be Base Rate Loans or Eurodollar Rate Loans, as further provided herein.”

(d)           Section 2.05(b)(v) is amended by inserting after the phrase “Term Loan Facility” where it appears in clause “first” thereof the phrase “and the Additional Term Facility, on a pro rata basis,”.

(e)           Section 2.06(b) is amended by inserting at the end thereof the following new Section 2.06(b)(iii):

“(iii) Each Additional Term Commitment shall be automatically and permanently reduced to zero on the date of the funding of applicable Additional Term Borrowing”.

(f)            Section 2.07(a) of the Credit Agreement is hereby amended and restated in its entirety to read as follows:

(f)            Schedule 2.01(a)(ii) is hereby added to the Credit Agreement in the form of the schedule set forth and attached as Exhibit A to Joinder No. 1.

(g)           A new Section 6.19 is hereby added to the Credit Agreement immediately after Section 6.18, to read as follows:

“6.19       Real Estate Deliverables.  Deliver to the Administrative Agent no later than August 31, 2012 (subject to extension in the sole discretion of the Administrative Agent):

(a) Evidence reasonably satisfactory to the Administrative Agent that an amendment (the “Mortgage Amendment”) to the Mortgage has been duly executed, acknowledged and delivered in a form suitable for filing or recording in all filing or recording offices that the Administrative Agent may deem reasonably necessary or desirable in order to continue a valid first and subsisting Lien on the property described therein in favor of the Administrative Agent for the benefit of the Secured Parties and that all filing, documentary, stamp, intangible and recording taxes and fees have been paid; and

(b) With respect to the Mortgage Amendment, fully paid date down and modification endorsements to the existing American Land Title Association insurance policy insuring the Mortgage in form and substance reasonably satisfactory to the Administrative Agent.”

SECTION 2.           Additional Term Lenders.  Each Person that executes a signature page to this Joinder as an Additional Term Lender hereby acknowledges that it is, from and after the Additional Term Loan Effective Date, an “Additional Term Lender” for all purposes under the Credit Agreement and has all of the rights and obligations of an Additional Term Lender under the Credit Agreement as amended hereby.

SECTION 3.           Conditions to Effectiveness of Sections 1 and 2.  Sections 1 and 2 of this Joinder shall become effective on the date when, and only when, the following conditions shall have been satisfied (such date, the “Additional Term Loan Effective Date”):