Browse Prior Art Database

Method to Make Wide Lines Thicker Without an Added Photo Mask

IP.com Disclosure Number: IPCOM000100927D
Original Publication Date: 1990-Jun-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Cronin, JE: AUTHOR [+2]

Abstract

Lines are designed to be wider when reduced electrical resistance is required. Thus, when wider lines also become thicker, the width of wide lines can be minimized and line density is thereby reduced. This process uses a temporary sidewall coating as masking material to protect narrow line regions while wide line regions are etched deeper in a damascene line definition process.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 91% of the total text.

Method to Make Wide Lines Thicker Without an Added Photo Mask

       Lines are designed to be wider when reduced electrical
resistance is required.  Thus, when wider lines also become thicker,
the width of wide lines can be minimized and line density is thereby
reduced.  This process uses a temporary sidewall coating as masking
material to protect narrow line regions while wide line regions are
etched deeper in a damascene line definition process.

      Referring to Fig. 1, an opening W wide and an opening N wide
are defined by photomasking and etching etch-stop layer 10 and
insulating material 12 to depth d.  Temporary sidewall masking
material 14 is conformally deposited and anisotropically etched back
until only vertical sidewalls remain coated.  The thickness of
material 14 is sufficient to leave no exposed material 12 in lines N
wide after the etch- back.  Then, exposed insulator 12 is etched to
depth D.

      Temporary masking material 14 is selectively removed and conduc
tor 16 is conformally deposited and planarized to result in the cross
section shown in Fig. 2.

      Though the example given is for a process for defining
conductive lines in an insulating matrix, a pattern of any material
may be formed in a matrix of another material.

      A practical set of materials for the conductive line case is
polyimide for insulator 12, silicon nitride for etch stop 10,
parylene for temporary masking material 14, and tungsten for
conductor 16.

...