Browse Prior Art Database

Improving the Yield and Reliability During the Production of Monolithic Integrated Circuits

IP.com Disclosure Number: IPCOM000041914D
Original Publication Date: 1984-Mar-01
Included in the Prior Art Database: 2005-Feb-03
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Garben, B: AUTHOR [+2]

Abstract

During the production of monolithic integrated semiconductor circuits, ohmic contact 1 to silicon 2 is produced by means of a mask 3. Semiconductor technologies for high integration densities use a double layer, for example, Si3N4 on SiO2, as mask material for defining the geometry of contact 1. During the etching of the contact hole 4 (Fig. 1), a window 5, etched into the Si3N4 layer, serves as an etching mask for the SiO2 layer. This step produces an overhang 6 of the Si3N4 layer over the SiO2 layer. Ohmic contact 1 is produced by vapor depositing a contact metal 8, using a photoresist mask 7 applied to the Si3N4 layer. Upon application of photoresist mask 7, residues 9 of the photoresist penetrate below the nitride overhang 6 of the contact hole 4.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 2

Improving the Yield and Reliability During the Production of Monolithic Integrated Circuits

During the production of monolithic integrated semiconductor circuits, ohmic contact 1 to silicon 2 is produced by means of a mask 3. Semiconductor technologies for high integration densities use a double layer, for example, Si3N4 on SiO2, as mask material for defining the geometry of contact 1. During the etching of the contact hole 4 (Fig. 1), a window 5, etched into the Si3N4 layer, serves as an etching mask for the SiO2 layer. This step produces an overhang 6 of the Si3N4 layer over the SiO2 layer. Ohmic contact 1 is produced by vapor depositing a contact metal 8, using a photoresist mask 7 applied to the Si3N4 layer. Upon application of photoresist mask 7, residues 9 of the photoresist penetrate below the nitride overhang 6 of the contact hole 4. These contaminating residues 9, which can no longer be removed after vapor deposition of the contact metal 8, lead to circuit failures. Therefore, contact metal 8 should cover contact hole 4 only partly (Fig. 2) and not completely, as shown in Fig. 1. This has the advantage that the solvent, used to remove photoresist mask 7 after vapor deposition of the contact metal 8, also penetrates below the nitride overhang 6 of contact hole 4, dissolving any photoresist residues 9 and thus improving the yield.

1

Page 2 of 2

2

[This page contains 2 pictures or other non-text objects]