Controlled metal-semiconductor sintering/alloying by one-directional reverse illumination

Patent · Fri Jan 01 00:00:00 EST 1993

OSTI ID:868831

Sopori, Bhushan L ^[1]

---

1. Denver, CO

Metal strips deposited on a top surface of a semiconductor substrate are sintered at one temperature simultaneously with alloying a metal layer on the bottom surface at a second, higher temperature. This simultaneous sintering of metal strips and alloying a metal layer on opposite surfaces of the substrate at different temperatures is accomplished by directing infrared radiation through the top surface to the interface of the bottom surface with the metal layer where the radiation is absorbed to create a primary hot zone with a temperature high enough to melt and alloy the metal layer with the bottom surface of the substrate. Secondary heat effects, including heat conducted through the substrate from the primary hot zone and heat created by infrared radiation reflected from the metal layer to the metal strips, as well as heat created from some primary absorption by the metal strips, combine to create secondary hot zones at the interfaces of the metal strips with the top surface of the substrate. These secondary hot zones are not as hot as the primary hot zone, but they are hot enough to sinter the metal strips to the substrate.

• Research Organization: Midwest Research Institute, Kansas City, MO (United States)
• DOE Contract Number: AC02-83CH10093
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 5223453
• OSTI ID: 868831
• Country of Publication: United States
• Language: English

Related Subjects

controlled
metal-semiconductor
sintering
alloying
one-directional
reverse
illumination
metal
strips
deposited
top
surface
semiconductor
substrate
sintered
temperature
simultaneously
layer
bottom
simultaneous
opposite
surfaces
temperatures
accomplished
directing
infrared
radiation
interface
absorbed
create
primary
hot
zone
melt
alloy
secondary
heat
effects
including
conducted
created
reflected
absorption
combine
zones
interfaces
sinter
opposite surfaces
hot zone
top surface
semiconductor substrate
metal layer
infrared radiation
bottom surface
opposite surface
metal strips
metal strip
radiation reflected
temperature simultaneously
hot zones
including heat
site surface
/438/