Semiconductor device manufacturing: process – Formation of electrically isolated lateral semiconductive... – Having air-gap dielectric
Patent
1997-06-10
1999-03-09
Fourson, George
Semiconductor device manufacturing: process
Formation of electrically isolated lateral semiconductive...
Having air-gap dielectric
438701, 438713, 438978, 438424, H01L 2176
Patent
active
058800042
ABSTRACT:
A method of providing isolation structure in a semiconductor device having a shallow trench with a rounded top corner is provided for preventing stress centralization as well as current leakage of a device. The method includes the steps of: (a) sequentially forming a pad oxide layer and a silicon nitride layer on a semiconductor substrate; (b) forming an opening in the silicon nitride layer by a first anisotropic etching process, so as to expose an area for forming a shallow trench; (c) performing a wet etching process to remove the pad oxide layer within the opening, the wet etching process removing a portion of the pad oxide layer extending from the opening and under the silicon nitride layer; (d) performing an isotropic etching process to form a hollow with a rounded top corner in the semiconductor substrate, wherein the rounded top corner is located under the silicon nitride layer; and (e) continuously etching the hollow by a second anisotropic etching process using the silicon nitride layer as a mask, thereby forming a shallow trench having a rounded top corner in the semiconductor substrate.
REFERENCES:
patent: 5556797 (1996-09-01), Chi et al.
patent: 5578518 (1996-11-01), Koike et al.
patent: 5683908 (1997-11-01), Miyashita et al.
Fourson George
Winbond Electronics Corp.
LandOfFree
Trench isolation process does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Trench isolation process, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Trench isolation process will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1320453