Browse Prior Art Database

Temperature Controlled Traps and Vacuum Forelines for LPCVD Systems

IP.com Disclosure Number: IPCOM000121177D
Original Publication Date: 1991-Jul-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 1 page(s) / 51K

Publishing Venue

IBM

Related People

Copeland, WR: AUTHOR [+3]

Abstract

Typically, Silicon Dioxide is used as an interlayer dielectric film for device isolation. This film is deposited by an LPCVD (Low Pressure Chemical Vaport Deposition) furnace system. TEOS (Tetraethylorthosilicate) is used as a reactant, in conjunction with Silicon and Oxygen. All critical parameters for achieving the desired deposition film characteristics, i.e., gas and liquid flows, pressure and time, are carefully calibrated and controlled.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 74% of the total text.

Temperature Controlled Traps and Vacuum Forelines for LPCVD Systems

      Typically, Silicon Dioxide is used as an interlayer dielectric
film for device isolation.  This film is deposited by an LPCVD (Low
Pressure Chemical Vaport Deposition) furnace system.  TEOS
(Tetraethylorthosilicate) is used as a reactant, in conjunction with
Silicon and Oxygen.  All critical parameters for achieving the
desired deposition film characteristics, i.e., gas and liquid flows,
pressure and time, are carefully calibrated and controlled.

      In this process, during manufacturing conditions, the
particulate levels encountered would dramatically increase when the
tools were processing numerous jobs consecutively. The normal remedy
to reduce particulate contamination, although not always successful,
was to put the system in an extended (two hour or longer) pump down
and purge cycle. With the current small geometry devices, it is
paramount to reduce the amount of particles, as well as to be more
critical of submicron particles.  With this criteria, our tool set
was unable to repeatedly meet particulate requirements.

      During the engineering study to reduce particulates, it was
determined by RGA (Residual Gas Analysis) that residual and unreacted
TEOS was condensing on the cooler surfaces of the vacuum system
foreline and trap.  When the system was being evacuated for the next
run, this residual TEOS would outgas and coat the new wafers causing
surface contamination (as re...