Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Glass Planarization for Borderless Contact Etch with Reduced Glass Etch Requirements

IP.com Disclosure Number: IPCOM000108869D
Original Publication Date: 1992-Jun-01
Included in the Prior Art Database: 2005-Mar-23
Document File: 1 page(s) / 41K

Publishing Venue

IBM

Related People

Dinklage, JB: AUTHOR [+3]

Abstract

A method for achieving highly planarized glass layers on semiconductor wafers is described. Most so-called planarizing methods are actually smoothing processes since they are not effective in eliminating height variations when topography varies greatly in density over sufficiently long distances. An automatic planarization mask generation technique is proposed to permit etching of phosphosilicate glass (PSG) over topographically high portions of wafers to improve planarity.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 99% of the total text.

Glass Planarization for Borderless Contact Etch with Reduced Glass Etch Requirements

      A method for achieving highly planarized glass layers on
semiconductor wafers is described.  Most so-called planarizing
methods are actually smoothing processes since they are not effective
in eliminating height variations when topography varies greatly in
density over sufficiently long distances.  An automatic planarization
mask generation technique is proposed to permit etching of
phosphosilicate glass (PSG) over topographically high portions of
wafers to improve planarity.

      The process flow to achieve the improved planarization proceeds
as follows:
1.   Normal wafer processing up to point of planarizing passivation.
2.   Passivation employing a typical PSG or BPSG deposition.
3.   Apply a resist layer and expose using an automatically generated
mask.
4.   Develop the resist.
5.   Apply a second resist/polymeric layer.  The mask applied in the
previous step is designed so that this second layer will be
substantially planar over all underlying structures.
6.   Perform resist/PSG planarizing etch.
7.   Remove residual high points employing a short polishing cycle.
8.   Proceed with normal contact and metalization processing.

      A substantial improvement in PSG thickness variation results.
Reduced tolerance on PSG height improves the process window in
etching of borderless contacts when employing contact etch-stop
layers.

      Disclosed an...