High-quality hydrogen-diluted a-SiNx:H films deposited by hot-wire chemical vapor deposition

We have studied the effect of H dilution on silicon nitride films deposited by the hot-wire chemical vapor deposition (HWCVD) technique using SiH(4), NH(3), and H(2) gases. We found that H dilution significantly enhances the properties at silicon nitride films. The N content in the film increases by more than 2 times compared to the film without dilution, based on FTIR measurements. As a result, we can achieve high-quality a-SiN(x):H films at low substrate temperature using a much lower gas ratio Of NH(3)/SiH(4) (similar to1) compared to a ratio of about 100 for conventional deposition by HWCVD. We also found that dilution decreases the H content in the films. More importantly, diluted SiN(x). films are conformal. Scanning electron microscopy measurements show a nearly 100% surface coverage over a sharp object. Electric breakdown measurement shows a well-insulated film with more then a few MV/cm for the breakdown field.