Chemical Vapor Deposition of Selective Epitaxial Silicon Layers

Abstract

A process of selective epitaxial growth of silicon on an oxide-patterned substrate is developed, and the quality of the deposited silicon film is characterized. Good selectivity is achieved in depositing silicon only in the area where the silicon substrate is exposed and not in the areas covered with the oxide. The quality of the deposited silicon film is investigated by SEM and TEM. No dislocations are observed in the samples investigated by TEM. The j unction leakage of diodes fabricated on these samples is measured. At a reverse bias of 5V, a leakage current density of 30 nA/cm 2 is obtained. Precleaning at 1025~ for 3 rain in H2 for the patterned Si substrate was found to be adequate to produce good quality Si films. The size of the facet was found to be reduced by lowering the flow rate of the HC1 during the deposition.

Selective Epitaxial Growth in Deep Trenches for Integrated Photodetector Applications

“…Silicon photodiodes have existed for a long time (8), but have not been suitable for integration with silicon VLSI because of the absence of proper isolation. Here, we report results of selective epitaxial growth (SEG) (9) of Si in deep trenches which is intended to be the basic structure of a short wavelength (0.8-0.9 ~m) Si photodiode for integration with Si VLSI. To our knowledge, this is the first attempt to achieve SEG of thickness in excess of 30 ~m in a trench structure.…”