STUDIES ON SI+(+)B+ DUAL IMPLANTATIONS INTO THE TOP SILICON LAYER OF SIMNI MATERIAL

Abstract SIMNI material was formed by N + implantation into crystalline silicon wafers at 170 keV with a dose of 1.8 × 10 18 cm −2 and annealing at 1200° C for 2 h. The top silicon of these SIMNI wafers was amorphized at different depths by Si + implantation at three conditions: (1) 25 keV, 5 × 10 15 cm −2 ; (2) 140 keV, 5 × 10 15 cm −2 ; (3) 25 keV, 5 × 10 15 cm −2 + 80 keV, 5 × 10 15 cm −2 + 140 keV, 5 × 10 15 cm −2 . Then the three groups of SIMNI wafers and another group with no implantation by Si + were implanted by B + at 25 keV with a dose of 1 × 10 15 cm −2 , and annealed at a series of temperatures for 30 min. Glancing RBS/C measurement shows that an epitaxial regrowth toward the surface or the inner part of the top silicon exists for the samples in group (1) and (2), respectively, with increasing annealing temperature. No epitaxial regrowth exists for the samples in group (3). Raman measurement shows that a phase transformation from amorphized silicon to polysilicon exists for the top silicon of samples in group (3) when the annealing temperature is increased from 500° C to 600° C. SRP measurement shows that Si + + B + dual implantations are able to increase the activation rate of boron in the top silicon of SIMNI material.