AN EVALUATION OF CONTAMINATION FROM PLASMA IMMERSION ION-IMPLANTATION ON SILICON DEVICE CHARACTERISTICS

Silicon devices including diodes, metal oxide semiconductor capacitors, and p-channel metal oxide semiconductor transistors were fabricated by plasma immersion ion implantation (PIII) doping technique using a microwave multipolar bucket plasma system. B2H6 diluted in helium (1%) was used as the gas source. The contamination by helium, hydrogen, iron, sodium, and aluminum impurities was evaluated by secondary ion mass spectrometry measurements. During PIII processing in an aluminum chamber with a stainless steel wafer holder, no aluminum and a dose of 4.1 x 10(12)/cm2 of Fe were detected. Most of Fe ions were shielded by a thin layer of SiO2 during the device fabrications. Good quality devices have been demonstrated including low reverse current of 15 nA/cm2 (V(R) = -5 V) in diodes and reasonable lifetimes of the minority carriers such as tau(g) = 55.0 musec and = tau(r) 54.2 musec.