Browse Prior Art Database

Al/PtSi Schottky Barrier Diodes With a Diffusion Barrier

IP.com Disclosure Number: IPCOM000081135D
Original Publication Date: 1974-Apr-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Reith, TM: AUTHOR [+2]

Abstract

Because of the relatively large work function difference between Pt and Si, PtSi metallization in conjunction with low-doped n- type Si epitaxial layers can be used to form a Schottky barrier diode with high-forward voltages. Pt cannot be used, however, as a device interconnect metallurgy because of its high resistivity and poor adhesion to SiO(2) and Si(3)N(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

Al/PtSi Schottky Barrier Diodes With a Diffusion Barrier

Because of the relatively large work function difference between Pt and Si, PtSi metallization in conjunction with low-doped n- type Si epitaxial layers can be used to form a Schottky barrier diode with high-forward voltages. Pt cannot be used, however, as a device interconnect metallurgy because of its high resistivity and poor adhesion to SiO(2) and Si(3)N(4).

For many reasons, Al is a logical candidate for the interconnect metallurgy, but it reacts with PtSi, dissolving it to form the PtAl(2) intermetallic and free Si. Al is therefore not compatible with PtSi without modification. If a diffusion barrier is interposed between the PtSi and the Al, then there will be no reaction between the two and the high PtSi Schottky barrier diode characteristics will be preserved (see the figure).

Any number of metals, e.g., chromium, are suitable as diffusion barriers.

It should be recognized that it may be desirable to have two types of Schottky barrier diode structures, i.e., one with relatively high-forward voltage barrier characteristics and one with relatively low-forward voltage barrier characteristics, in a single integrated circuit. In such a case, the chrome diffusion barrier may be selectively formed only in those diodes which are to retain the high-forward voltage barrier characteristics.

1

Page 2 of 2

2

[This page contains 1 picture or other non-text object]