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Liquid Alloy Source for Dopants

IP.com Disclosure Number: IPCOM000039665D
Original Publication Date: 1987-Jul-01
Included in the Prior Art Database: 2005-Feb-01

Publishing Venue

IBM

Related People

Authors:
Delage, SL Ek, BA Ghez, R Iyer, SS [+details]

Abstract

In silicon molecular beam epitaxy (Si MBE), a dopant beam is used in neutral or ionized form to simultaneously dope Si films during epitaxial growth. Thermally-generated neutral beams are preferred for this purpose because the system is simple to implement and the growth is better understood and easy to accomplish. Unfortunately, the choice of N type dopants is severely restricted due to practical limitations. All the N type dopants have extremely high vapor pressures. This has several drawbacks. First, there is appreciable flux at temperatures as low as 250oC, typically used during bake-out and these species deposited on vacuum parts will re-evaporate when these parts warm up during growth.