Process for making self-aligned contacts

Claim 2

In an integrated circuit having a plurality of semiconductor devices fabricated on a substrate, a process for interconnecting the semiconductor devices comprising the following steps in the following order: A. depositing an insulating layer over said semiconductor devices; B. depositing a layer of polyimide over said insulating layer; C. depositing a first layer of photoresist over said polyimide layer; D. lithographically defining an interconnect wiring pattern in said first layer of photoresist; E. dry etching said interconnect wiring pattern into said polyimide layer; F. depositing a second layer of photoresist over said patterned polyimide layer; G. lithographically defining a pattern of contacts in said second layer of photoresist, said pattern of contacts overlying said patterned polyimide layer; H. transferring said pattern of contacts to said insulating layer; and I. depositing a layer of interconnect wiring, said interconnect wiring layer filling said pattern of contacts in said insulating layer and said interconnect wiring pattern in said polyimide layer.

Claim 3

The process as claimed in claim 1 including the step of removing said polyimide layer after depositing said interconnect wiring layer.

Claim 4

The process as claimed in claim 1 wherein said insulating layer is borophosphosilicate glass.

Claim 5

The process as claimed in claim 1 wherein said interconnect wiring layer is selected from the group consisting of aluminum, copper, silicon, titanium, tungsten, silver, gold or alloys or composites thereof.

Claim 6

The process as claimed in claim 1 wherein said interconnect wiring layer is deposited by evaporation or sputtering.

Claim 7

A process for interconnecting semiconductor devices comprising the following steps in the following order: A. providing a semiconductor substrate having a plurality of semiconductor devices formed therein; B. depositing an insulating layer over said semiconductor devices on said substrate; C. depositing a thin layer of polyamic acid over said insulating layer; D. curing said polyamic acid to form a layer of polyimide; E. depositing a first layer of photoresist over said polyimide layer; F. exposing said first layer of photoresist to optical or X-ray radiation through a mask defining an wiring pattern; G. developing said first layer of photoresist; H. etching said interconnect wiring pattern into said polyimide layer; I. removing said first layer of photoresist; J. depositing a second layer of photoresist over said patterned polyimide layer; K. lithographically defining a pattern of contacts in said second layer of photoresist, said pattern of contacts aligned with and overlying said patterned polyimide layer; L. transferring said pattern of contacts to said insulating layer; M. removing said second layer of photoresist; and N. conformally depositing a layer of interconnect wiring, said interconnect wiring layer filling said pattern of contacts in said insulating layer and said interconnect wiring pattern in said polyimide layer.

Claim 8

A process for interconnecting semiconductor devices comprising the following steps in the following order: A. providing a semiconductor substrate having a plurality of semiconductor devices formed therein; B. depositing an insulating layer over said semiconductor devices on said substrate; C. depositing a thin layer of polyamic acid over said insulating layer; D. curing said polyamic acid to form a layer of polyimide; E. depositing a first layer of photoresist over said polyimide layer; F. exposing said first layer of photoresist to optical or X-ray radiation through a mask defining an wiring pattern; G. developing said first layer of photoresist; H. etching said interconnect wiring pattern into said polyimide layer; I. removing said first layer of photoresist; J. depositing a second layer of photoresist over said patterned polyimide layer; K. lithographically defining a pattern of contacts in said second layer of photoresist, said pattern of contacts aligned with and overlying said patterned polyimide layer; L. transferring said pattern of contacts to said insulating layer; M. removing said second layer of photoresist; and N. conformally depositing a layer of interconnect wiring, said interconnect wiring layer filling said pattern of contacts in said insulating layer and said interconnect wiring pattern in said polyimide layer.

Claim 9

The process as claimed in claim 6 including the step of removing said polyimide layer after depositing said interconnect wiring layer.

Claim 10

The process as claimed in claim 6 wherein said insulating layer is borophosphosilicate glass.

Claim 11

The process as claimed in claim 6 wherein said interconnect wiring layer is selected from the group consisting of aluminum, copper, silicon, titanium, tungsten, silver, gold or alloys or composites thereof.