Invention Grant
- Patent Title: Etching of semiconductor structures that include titanium-based layers
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Application No.: US14079473Application Date: 2013-11-13
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Publication No.: US09330937B2Publication Date: 2016-05-03
- Inventor: Gregory Nowling , John Foster
- Applicant: Intermolecular Inc.
- Applicant Address: US CA San Jose
- Assignee: Intermolecular, Inc.
- Current Assignee: Intermolecular, Inc.
- Current Assignee Address: US CA San Jose
- Main IPC: C23F1/00
- IPC: C23F1/00 ; C03C15/00 ; C03C25/68 ; C25F3/00 ; H01L21/3213 ; H01L21/67 ; H01J37/32 ; C23F1/26 ; C23F4/00

Abstract:
Two-step process sequences uniformly etch both tungsten-based and titanium-based structures on a substrate. A sequence of wet etches using peroxide and heated nitric acid uniformly recesses a metal stack that includes W, TiN, and TiAl. W, TiN and TiC are uniformly recessed by a peroxide etch at ˜25 C followed by an acid solution with a very small amount of added peroxide at ˜60 C. TiC is etched without etching trench oxides or other metals in a work-function metal stack by either (1) highly-dilute of ultra-dilute HF at 25-35 C, (2) dilute HCl at 25-60 C, (3) dilute NH4OH at 25-60 C, or (4) solution (2) or (3) with small amounts of peroxide. Other metals in the stack may then be plasma-etched without being blocked by TiC residues.
Public/Granted literature
- US20150132953A1 Etching of semiconductor structures that include titanium-based layers Public/Granted day:2015-05-14
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