Browse Prior Art Database

Fabricating a Metal Base Transistor

IP.com Disclosure Number: IPCOM000073558D
Original Publication Date: 1971-Jan-01
Included in the Prior Art Database: 2005-Feb-22
Document File: 2 page(s) / 62K

Publishing Venue

IBM

Related People

Anantha, NG: AUTHOR

Abstract

This method for fabricating a metal base transistor is compatible with planar semiconductor technology.

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Fabricating a Metal Base Transistor

This method for fabricating a metal base transistor is compatible with planar semiconductor technology.

The metal base transistor, frequently termed a "hot-electron transistor", has a metallic layer which functions as a base. The current from the emitter to the collector traverses the base in the form of hot electrons. The good conductivity of the metal base and the short switching times at the metal semiconductor junctions make it possible to utilize a metal base transistor at substantially higher frequencies than other types of transistors. The metal base transistor also has a low input impedance, a high output impedance, a current gain which is essentially independent of current level, and a low feedback factor.

In the method, a SiO(2) layer 10 is deposited on a monocrystalline semiconductor substrate having a base 11 having a N+ layer with a N epitaxial region deposited thereon. A window layer 12, having the configuration shown in B, is formed in 10 and a layer 13 of Pt. is deposited therein and converted to platinum silicide (Ptsi). Subsequently, a SiO(2) layer 14 is deposited over layer 10 and a window 15 made therein over one end of original window 12. As shown in D, N-doped epitaxial silicon 16 is deposited in opening 15 over the Pt. silicide layer 13. Preferably, a large window exposing the bare silicon is made at the same time opening 15 is made which helps in preventing nucleation over the oxide during the formation...