Laser-induced melting of predeposited impurity doping technique used to fabricate shallow junctions

Abstract

Shallow p+ junctions have been fabricated using a new technique in which doping is accomplished by depositing boron film on a silicon surface by radio-frequency glow discharge (rf-GD) and melting locally with a pulsed XeCl excimer laser. Sheet resistivity as low as 15 Ω/⧠ was obtained by irradiation of a single laser pulse. The junction depth was 0.07–0.3 μm, depending on the laser energy density. Electrical characteristics of p+-n junctions which were formed by the laser doping technique subsequently subjected to a 400 °C, 1-h furnace anneal show essentially ideal diode behavior with an ideality factor of 1.03.