BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES (Policies)	3 Months Ended
	Mar. 29, 2015
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") for interim financial information and with the instructions to Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by such accounting principles for complete financial statements. In the opinion of management, all adjustments (which include normal recurring adjustments) considered necessary to present fairly each of the statement of financial position as of March 29, 2015, the statements of operations for the three months ended March 29, 2015 and March 30, 2014, statements of comprehensive income for the three months ended March 29, 2015 and March 30, 2014, and the statements of cash flows for the three months ended March 29, 2015 and March 30, 2014, as applicable, have been made. The condensed consolidated balance sheet as of December 31, 2014 has been derived from our audited financial statements as of such date, but does not include all disclosures required by U.S. GAAP. The accompanying unaudited condensed consolidated financial statements should be read in conjunction with our audited consolidated financial statements for the year ended December 31, 2014, which are included in the Annual Report on Form 10-K filed with the Securities and Exchange Commission on March 12, 2015. The condensed consolidated financial statements include the accounts of Mattson Technology, Inc. and our wholly-owned subsidiaries. All inter-company balances and transactions have been eliminated. The results of operations for the three months ended March 29, 2015 are not necessarily indicative of results that may be expected for the entire year ending December 31, 2015.
Fiscal Year	Fiscal Year Our fiscal year ends on December 31. We close our first fiscal quarter on the Sunday closest to March 31. Our second and third fiscal quarters are each 13 weeks long and our fourth quarter closes on December 31.
Use of Estimates	Use of Estimates The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reported periods. We evaluate our estimates on an ongoing basis, including those related to the useful lives and fair value of long-lived assets, estimates used to determine facility lease loss liabilities, measurement of warranty obligations, valuation allowances for deferred tax assets, the fair value of stock-based compensation, estimates for allowance for doubtful accounts, and valuation of excess and obsolete inventories. Our estimates and assumptions can be subjective and complex and, consequently, actual results could differ materially from those estimates.
Reclassifications	Reclassifications For presentation purposes, certain prior period amounts have been reclassified to conform to the reporting in the current period financial statements. These reclassifications do not affect our net income, cash flows or stockholders' equity.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In April 2015, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2015-03, Simplifying the Presentation of Debt Issuance Costs. Debt issuance costs are specified incremental costs, other than those paid to the lender, that are directly attributable to issuing a debt instrument (i.e., third party costs). Prior to the adoption of this standard, debt issuance costs were required to be presented in the balance sheet as a deferred charge (i.e., an asset). This presentation differed from the presentation for a debt discount, which is a direct adjustment to the carrying value of the debt (i.e., a contra liability). This new standard requires that all costs incurred to issue debt be presented in the balance sheet as a direct deduction from the carrying value of the debt. This new standard does not affect the recognition and measurement of debt issuance costs. ASU 2015-03 will be effective for us in the first quarter of fiscal 2016, with early adoption permitted. We are currently evaluating the impact that the implementation of this standard will have on our financial statements. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers. The FASB issued ASU 2014-09 to clarify the principles for recognizing revenue and to develop a common revenue standard for GAAP and International Financial Reporting Standards. The standard outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes the most current revenue recognition guidance. This guidance is effective for fiscal years and interim periods within those years beginning after December 15, 2016, which is effective for us as of the first quarter of our fiscal year ending December 31, 2017. On April 1, 2015, the FASB agreed to propose delaying the effective date by one year. We are currently evaluating the impact that the implementation of this standard will have on our financial statements. There were no other recent accounting pronouncements or changes in accounting pronouncements during the three months ended March 29, 2015 compared to the recent accounting pronouncements described in our Annual Report on Form 10-K for the fiscal year ended December 31, 2014 that are of significance or potential significance to us.

Disclosure of accounting policy for determining an entity's fiscal year or other fiscal period. This disclosure may include identification of the fiscal period end-date, the length of the fiscal period, any reporting period lag between the entity and its subsidiaries, or equity investees. If a reporting lag exists, the closing date of the entity having a different period end is generally noted, along with an explanation of the necessity for using different closing dates. Any intervening events that materially affect the entity's financial position or results of operations are generally also disclosed.

+ References+ Details