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Browse Prior Art Database

Low Temperature Selective Nitridization of Metals in Polycide Stack Structures

IP.com Disclosure Number: IPCOM000110739D
Original Publication Date: 1992-Dec-01
Included in the Prior Art Database: 2005-Mar-25
Document File: 1 page(s) / 72K

Publishing Venue

IBM

Related People

Agnello, PD: AUTHOR [+5]

Abstract

Disclosed here is a process that prevents the oxidation of the metal gate conductor in a POLYCIDE stack structure, using a low temperature (720~C) NH3 anneal after RIE definition, but before the oxidation which is necessary to repair RIE damage of the gate oxide.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 72% of the total text.

Low Temperature Selective Nitridization of Metals in Polycide Stack Structures

      Disclosed here is a process that prevents the oxidation of the
metal gate conductor in a POLYCIDE stack structure, using a low
temperature (720~C) NH3 anneal after RIE definition, but before the
oxidation which is necessary to repair RIE damage of the gate oxide.

      Submicron POLYCIDE processes are useful in the fabrication of
high density circuits because they can be used to achieve a low
resistance gate conductor with a gate stack that incorporates an etch
stop that allows contacting the source/drain diffusions in a
borderless fashion with respect to the gate.  The POLYCIDE process
involves the formation of a highly conductive gate electrode before
gate definition.  This allows the inclusion of an etch stop material,
such as silicon nitride on the gate stack without a critical masking
step.  A disadvantage of the POLYCIDE process is that during the gate
oxide repair oxidation required after gate definition, the metal is
already part of the gate stack and may oxidize.

      Disclosed here is a process of nitridizing the gate stack
before gate oxide repair, subject to the following constraints: The
nitridization must only nitridize the gate conductor, but not the
gate oxide.  The nitridized layer must protect the gate conductor
from oxidation during the subsequent gate repair oxidation, but must
allow further oxidation of the Si in the vicinity of the gate oxide.
The ni...