Valuation method of dielectric breakdown lifetime of gate insulating film, valuation device of dielectric breakdown lifetime of gate insulating film and program for evaluating dielectric breakdown lifetime of gate insulating film

Abstract

The present invention discloses a valuation method, a valuation device and a valuation program of dielectric breakdown lifetime of a gate insulating film, used for evaluating dielectric breakdown lifetime of the gate insulating film of a MOS type element. The valuation method includes the following steps of: deciding a Weibull slope of lifetime distribution until reaching a soft breakdown of the gate insulating film of the MOS type element; deciding a detection condition of the soft breakdown from the decided Weibull slope after the above step; and executing a dielectric breakdown test by using the decided detection condition. The valuation device includes: a voltage supply unit to supply a voltage for the MOS type element so as to apply an electric stress to the MOS type element; a current measuring unit to measure a leakage current across the gate insulating film; and a temperature holding unit to hold temperature of a testing element containing the MOS type element to below a room temperature. According to the valuation method, the valuation device and the valuation program, the dielectric breakdown lifetime can be determined suitably.

Description

[0001] Cross References to Related Applications [0002] This application contains subject matter related to that disclosed in Japanese Priority Patent Application JP 2009-185966 filed in Japan Patent Office on Aug. 10, 2009, the entire content of which is hereby incorporated by reference In this article. technical field [0003] The invention relates to a gate insulating film dielectric breakdown life evaluation method, evaluation device and evaluation program for evaluating the dielectric breakdown life of the gate insulating film in a MOS type semiconductor element. Background technique [0004] Hitherto, in order to evaluate the dielectric breakdown lifetime of the gate insulating film in the MOS type semiconductor element, a judgment test of the dielectric breakdown lifetime of the gate insulating film has been performed. [0005] Next, a test method for determining the dielectric breakdown lifetime of a gate insulating film in an integrated circuit including a MOS typ...

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Problems solved by technology

Furthermore, there is no clear way to unambiguously determine soft breakdown

[0037] In the method disclosed in Non-Patent Document 3, there is the following fatal problem: There is no clear guideline on how to set the threshold in the method disclosed in Non-Patent Document 3

[0041] However, the amount of noise does not undergo a definite change to the extent disclosed in each document, and it is difficult to apply each of the above methods to a gate insulating film having the above film thickness

[0042] In Non-Patent Document 4, an oxide film having a film thickness of 2.0 nm or more is processed, so it is highly likely that it will be difficult to apply the above method to a film having a thickness of 1.2 nm

[0043] In the prior art, the judgment method of soft breakdown is determined, and the data is statistically processed by this judgment method, thereby calculating the Weibull distribution parameters of soft breakdown, so it is difficult to uniquely determine these parameters

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