Simple Method for Phosphorus Diffusion on <100> Oriented P-Type Silicon Using New Phosphorus Gel as Dopant

Abstract

In this work, we try to make a p-type monocristalline silicon pn junction using an easier doping method. We combined spin-coating thin film deposition method and solid doping technique. This technique can be considered as variety of the SOD method. In this study, phosphorous-based gel compounds was prepared and deposited by spin coating. Heat treatment would thus, after deposition of thin layer, diffuse phosphorus atoms into the substrate to obtain a pn diode. Study by Secondary Ions Mass Spectrometry (SIMS) showed a surface phosphorus concentration of 10 20 at/cm 3 incorporated within the silicon substrate to a depth of 300 nm. The microwave phase-shift (µW-PS) technique is used to determine the bulk lifetime ( τ b) of minority carriers. In this technique, the phase-shift between a microwave beam (10 GHz) and a sine-modulated infrared excitation is related to τb and to the surface recombination velocity (S) (Palais, Clerc, Arcari, Stemmer & Martinuzzi, 2003). The lifetime τb mean values vary from 7 µs for a p-type Silicon to 97 µs for phosphorus-diffused silicon. The surface recombination velocity S varies from around 500 to 1000 cm.s -1 .