Hydrogen in semi-insulating polycrystalline silicon films

Abstract
Infrared (IR) spectroscopy, nuclear reaction analysis (NRA), and Rutherford backscattering (RBS) were used on semi‐insulating polycrystalline silicon (SIPOS) films deposited at atmospheric pressure (AP) and low pressure (LP) to determine film composition and hydrogen content. The amount of hydrogen in SIPOS ranges from less than 0.1 at. % H for films annealed in nitrogen at 800 °C for 30 min to 11 at. % H for higher oxygen content LP SIPOS films. For AP SIPOS films, the H content is directly proportional to the O content of the film and is uniformly distributed with depth into the SIPOS film. Based on the absorption cross section, the narrow, very weak 2270‐cm−1 peak in the IR is identified as the Si‐H absorption. The higher oxygen content LP SIPOS film contains additional H not bound as Si‐H. The IR, NRA, and RBS data are interpreted in terms of a structural model involving Si‐H and Si‐O where the O is nonbridging. The 865‐cm−1 peak in the IR is believed due to this nonbridging O‐Si interaction.