Identification of nitriding mechanisms in high purity reaction bonded silicon nitride.

摘要

The rapid, low-temperature nitriding results from surface effects on the Si particles beginning with loss of chemisorbed H and sequential formation of thin amorphous Si nitride layers. Rapid complete conversion to Si(sub 3)N(sub 4) during the fast reaction can be inhibited when either too few or too many nuclei form on Si particels. Optimally, (approximately) 10 Si(sub 3)N(sub 4) nuclei form per Si particles under rapid, complete nitridation conditions. Nitridation during the slow reaction period appears to progress by both continued reaction of nonpreferred Si(sub 3)N(sub 4) growth interfaces and direct nitridation of the remaining Si/vapor interfaces.