Hydrogen introduction into p+ silicon by boiling in water and its application to deep-level transient spectroscopy measurements

Hydrogen introduction into p+ silicon was carried out by boiling in water to reduce the surface carrier concentration due to the formation of boron–hydrogen pairs. Carrier concentration profiles were estimated from Schottky diodes fabricated successfully on the hydrogenated surfaces. Boiling for times longer than 30 min was not effective for the reduction of the carrier concentration near the surface. Instead, the repetition of the process, which consists of removal of the oxide and boiling in water for 15 min, was found to introduce a large quantity of hydrogen. For the total boiling time of 28 h, the carrier concentration decreased from the original value of mid 1018 to 2×1016 cm−3 at the depth of 170 nm. Iron–boron pairs (Ev+0.1 eV) were detected by deep-level transient spectroscopy measurements on hydrogenated p+ silicon, which was intentionally iron-contaminated.