Polycrystalline silicon deposited on glass by subatmospheric-pressure chemical vapour deposition at a high rate

Abstract

Amorphous silicon films have been deposited on glass by subatmosphericpressure chemical vapour deposition and then crystallized by solid-phase crystallization. The structural and electrical properties of these polycrystalline silicon films are presented in this work. Good crystalline quality at a deposition pressure of about 400 mbar has been achieved as well as values of the mobilitylifetime product above 10⁻⁵cm²V⁻¹ and an ambipolar diffusion length near 200 nm. Depending upon the deposition temperature and pressure, growth rates of up to 20 μm h⁻¹ can be obtained. In-situ doping with arsenic and boron has been studied using Hall effect measurements. High mobilities around 45cm²V⁻¹s⁻¹ have been attained for highly n-type doped samples and mobilities in the range from 20 to 30 cm² V⁻¹ s⁻¹ for boron-doped samples.