US 6,143,618 AGranted

Procedure for elimating flourine degradation of WSi.sub.x /oxide/polysilicon capacitors

AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.

InventorsHsin-Pai Chen, Ching-Tang Tsai, Tien-Chen Chang, Yung-Haw Liaw

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Abstract

A method for forming a polycide/oxide/polysilicon capacitor on a silicon wafer with improved dielectric stability and reliability is described wherein an in-situ high temperature anneal is applied to the wafer within a CVD reactor immediately prior to the deposition of the silicon oxide capacitor dielectric layer. The in-situ anneal causes sufficient fluorine outgassing of the polycide layer to prevent fluorine degradation of the subsequently deposited oxide capacitor dielectric. The capacitance of the completed capacitor is increased by as much as 10% when compared to a comparable not in-situ anneal conducted prior to the insertion of the wafer into the CVD reactor.

Claims20

Dependent claims

A method for depositing a silicon oxide dielectric layer on a polycide layer comprising:

(a) providing a substrate having a polycide layer;
(b) loading said substrate into a CVD reactor at a first temperature;
(c) evacuating said CVD reactor;
(d) ramping said substrate to a second temperature;
(e) introducing a first gas flow into said CVD reactor;
(f) ramping said substrate to a third temperature;
(g) maintaining said substrate at said third temperature and said first gas flow for a time period;
(h) ramping said substrate to a fourth temperature, said fourth temperature being less than said third temperature;
(i) purging said reactor with a gas flow containing N.sub.2 and N.sub.2 O;
(j) introducing a third gas flow containing dichlorosilane and N.sub.2 O into said CVD reactor, whereby a silicon oxide dielectric layer is deposited on said substrate at said fourth temperature;
(k) introducing a fourth gas flow in said reactor;
(l) ramping said substrate to said first temperature;
and
(m) unloading said substrate.

11 more elements

Dependencies are inferred from the claim text.