Controlled Atomic Layer Doping and ALD MOSFET Fabrication in Si

Abstract

Controlled atomic layer doping (ALD) in Si is obtained, combining the adsorption and desorption behaviours of Sb in Si molecular beam epitaxy and solid phase epitaxy. SIMS and CV measurements confirm the sharp doping profile. It is shown by Hall measurements that the carrier concentration varies from 9×10¹¹ to 8×10¹³ cm^-2 and the mobility from 250 to 60 cm²V^-1s^-1 when the Sb concentration is changed from 0.0015 to 1 monolayer. The first ALD-MOSFET, with a gate length of 8 µm and a gate oxide thickness of 100 nm, is made using the ALD layer as the conducting channel, and has a transconductance of 7 mS/mm.