Browse Prior Art Database

Attaching Thermocouple Junctions to Silicon Wafers

IP.com Disclosure Number: IPCOM000077277D
Original Publication Date: 1972-Jul-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Logan, JS: AUTHOR [+2]

Abstract

By this method a thermocouple junction is bonded to the surface of a wafer with glass, which maintains the junction in firm contact with the wafer and provides electrical isolation about the junction.

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Attaching Thermocouple Junctions to Silicon Wafers

By this method a thermocouple junction is bonded to the surface of a wafer with glass, which maintains the junction in firm contact with the wafer and provides electrical isolation about the junction.

It is frequently desirable to monitor the temperature of a semiconductor wafer while the wafer is being processed. Bonding a thermocouple junction, which serves as a temperature sensor to a wafer, without weakening the wafer, causing stresses on the wafer, or presenting a potential out-gassing source has been a problem.

In this method, a thermocouple junction 10 is placed in contact with a silicon wafer 12 with a small tubular piece of glass 14 surrounding the junction. The assembly is placed in a furnace at approximately 1050 degrees C, purged with forming gas, for 5 to 10 minutes or longer. Lower or higher furnace temperatures may be used and the time interval adjusted accordingly. In the furnace the glass tube 14 melts about the thermocouple junction which is actually fused into the wafer surface. The junction fusing into the silicon surface causes a slight concave effect on the back of the wafer, allowing it to rest flat when used. The glass cylinder 14 forms a bead 16 which bonds to the wafer surface and, when cooled, makes a strong mechanical connection while insulating the junction extension wires from each other.

If a wafer is required where the thermocouple junction should not fuse into the wafer or a low p...