The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 18, 2012
Filed:
May. 07, 2010
Eugene C. Davis, McKinney, TX (US);
Binghua HU, Plano, TX (US);
Sopa Chevacharoenkul, Richardson, TX (US);
Prakash D. Dev, Lubbock, TX (US);
Eugene C. Davis, McKinney, TX (US);
Binghua Hu, Plano, TX (US);
Sopa Chevacharoenkul, Richardson, TX (US);
Prakash D. Dev, Lubbock, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A one-step CMP process for polishing three or more layer film stacks on a wafer having a multilayer film stack thereon including a silicon nitride (SiNx) layer on its semiconductor surface, and a silicon oxide layer on the SiNx layer, wherein trench access vias extend through the silicon oxide layer and SiNx layer to trenches formed into the semiconductor surface, and wherein a polysilicon layer fills the trench access vias, fills the trenches, and is on the silicon oxide layer. CMP polishes the multilayer film stack with a slurry including slurry particles including at least one of silica and ceria. The CMP provides a removal rate (RR) for the polysilicon layer > a RR for the silicon oxide layer > a RR for the SiNx layer. The CMP process is continued to remove the polysilicon layer, silicon oxide layer and a portion of the SiNx layer to stop on the SiNx layer. Optical endpointing during CMP can provide a predetermined remaining thickness range for the SiNx layer.