US 6,037,018 A · Shallow trench isolation filled by high density plasma chemical vapor deposition

Abstract

A method for filling shallow trenches 28 with a HDPCVD oxide 50. The invention has two liners: (a) a thermal oxide liner 36 and (b) an overlying conformal O.sub.3 -TEOS protective liner 40. The O.sub.3 -TEOS protective liner 40 prevents the HDPCVD oxide 50 from sputter damaging the trench sidewalls and the masking layer 24. The O.sub.3 -TEOS layer has novel process temperature (400 to 560.degree. C.) and low pressure (40 to 80 torr) that allows the O.sub.3 -TEOS layer to deposit uniformly over thermal oxide liner 36. The method begins by forming pad oxide layer 20 and a barrier layer 24 over a substrate. A trench 28 is formed in the substrate 10 through the pad oxide layer 20 and the barrier layer 24. A thermal oxide liner 36 and a protective O.sub.3 -TEOS liner layer 40 are formed over the walls of the trench 28 and over the barrier layer 24. Lastly, a high density plasma chemical vapor deposition (HDPCVD) oxide layer 50 is formed over the protective liner layer 40 filling the trench 28.

Claims18

Dependent claims

A method of fabricating a HDPCVD oxide filled shallow trench isolation comprising the steps of:

a) forming a pad oxide layer over a semiconductor substrate;
b) forming a barrier layer over said pad oxide layer;
c) forming a trench in said semiconductor substrate through said pad oxide layer and said barrier layer;
said trench having sidewalls and a bottom;
d) forming a thermal oxide layer over said sidewalls and said bottom of said trench;
e) forming a protective liner layer on said thermal oxide layer and over said barrier layer;
said protective liner layer being composed of silicon oxide formed by an O.sub.3 -TEOS process at a temperature between 400 and 560.degree. C.;
f) forming an oxide layer using a HDPCVD process over said protective liner layer filling said trench.

5 more elements

A method of fabricating a HDPCVD oxide filled shallow trench isolation comprising the steps of:

a) forming pad oxide layer over a semiconductor substrate;
b) forming a barrier layer over said pad oxide layer;
c) forming a trench in said semiconductor substrate through said pad oxide layer and said barrier layer;
said trench having sidewalls and a bottom;
d) forming a thermal oxide layer over said sidewalls and said bottom of said trench;
e) forming a protective liner layer on said thermal oxide layer and over said barrier layer;
said protective liner layer is composed of silicon oxide formed by a O.sub.3 -TEOS process;
(e1) said protective liner layer having a thickness in a range of between about 300 and 1000 .ANG.;
said protective liner layer is formed using a LPCVD process having a O.sub.3 flow rate between about 4000 and 6000 sccm, a TEOS flow rate between 380 and 570 mgm in a He flow rate between 3200 and 4800 sccm, a pressure between 48 and 72 torr;
a temperature between 400 and 560.degree. C.;
(e2) after said protective liner layer is formed, densifying said protective liner at a temperature between 900 and 1100.degree. C. for a time between about 1.6 and 2.4 hours;
and in a N.sub.2 environment;
f) forming an oxide layer using a HDPCVD process over said protective liner layer filling said trench 28;
(f1) said oxide layer having a thickness in a range of between about 4800 and 7200 .ANG.;
said oxide layer is formed using a HDPCVD process comprising:
a HDPCVD-sputter rate between about 1100 and 1650 .ANG./min;
deposit to sputter ratio between 5.5 and 6.5;
an O.sub.2 flow between 215 and 320 sccm;
a SiH.sub.4 gas flow between 105 and 158 sccm;
an Ar flow rate between 100 and 150 sccm;
at a pressure between 9 and 13 torr and at a temperature between 450 and 600.degree. C.

18 more elements

Dependencies are inferred from the claim text.

Shallow trench isolation filled by high density plasma chemical vapor deposition

Life of this patent

Shallow trench isolation filled by high density plasma chemical vapor deposition

Life of this patent

Abstract

Claims18