US 2004/0103715 A1Published application

Leakage detecting method for use in oxidizing system of forming oxide layer

AssigneeMosel Vitelic, Inc.

InventorsYung Nan Liu, Cheng Kuo Tsou, Yuh Ju Lee, Ching Cheng Hsieh

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Abstract

Embodiments of the present invention are directed to providing a leakage detecting method for use in an oxidizing system of forming an oxide layer so as to shorten leakage detecting time period. In one embodiment, a leakage detecting method for use in an oxidizing system of forming an oxide layer comprises performing oxidizing processes on a plurality of test wafers in a plurality of test runs under a specified operating condition in an oxidizing system having an oxidizing chamber to form oxide layers on the test wafers having a plurality of oxide thicknesses for the plurality of test runs by flowing an oxidizing gas through the oxidizing chamber containing the test wafers. An oxygen concentration of the oxidizing gas exiting the oxidizing chamber is measured in each of the plurality of test runs. The method further comprises obtaining a correlation between the measured oxygen concentrations and the oxide thicknesses for the plurality of test runs to identify a threshold oxygen concentration corresponding to a maximum acceptable oxide thickness. An oxygen concentration greater than the threshold oxygen concentration indicates gas leakage in the oxidizing system.

Claims18

Dependent claims

A leakage detecting method for use in an oxidizing system of forming an oxide layer, the method comprising the steps of:

(a) providing an oxidizing system having an oxidizing chamber and an oxygen concentration analyzer installed in a bypass of an exhaust pipe of said oxidizing chamber;
(b) performing an oxidizing process on a test wafer in a test run under a specified operating condition in said oxidizing system by flowing an oxidizing gas through said oxidizing chamber containing said test wafer;
(c) measuring an oxygen concentration of said oxidizing gas exiting said oxidizing chamber in said test run by said oxygen concentration analyzer;
(d) measuring the oxide thickness of said test wafer after said test run;
(e) repeating (b), (c), and (d) for a plurality of test runs to obtain a correlation between the measured oxygen concentration and the oxide thickness for the plurality of test runs to identify an acceptable oxygen concentration corresponding to a maximum acceptable oxide thickness, wherein an oxygen concentration greater than said acceptable oxygen concentration indicates gas leakage in said oxidizing system;
(f) selecting a safety factor and multiplying said acceptable oxygen concentration with said safety factor to get a threshold oxygen concentration;
(g) performing a general oxidizing process on a working wafer under said specified operating condition in said oxidizing system;
wherein while said oxygen concentration analyzer starts to measure an oxygen concentration of said oxidizing gas exiting said oxidizing chamber, if said measured oxygen concentration is greater than said threshold oxygen concentration, an indication of gas leakage exists in said general oxidizing system.

5 more elements

A method for estimating a thickness of an oxide layer formed on a wafer, the method comprising:

providing an oxidizing system having an oxidizing chamber for forming an oxide layer on one or more substrates by flowing an oxidizing gas through said oxidizing chamber;
placing a working wafer in said oxidizing chamber of said oxidizing system;
performing an oxidizing process on said working wafer under a specified operating condition to form an oxide layer on said working wafer by flowing said oxidizing gas through said oxidizing chamber;
measuring an oxygen concentration of said oxidizing gas exiting said oxidizing chamber;
and
estimating a thickness of said oxide layer according to said measured oxygen concentration and a previously determined relation between oxide layer thicknesses formed on test substrates placed in said oxidizing chamber and oxygen concentrations of gases exiting said oxidizing chamber in test runs of oxidizing processes performed on the test substrates under said specified operating condition.

3 more elements

Dependencies are inferred from the claim text.