T. Watanabe et al., ATOMIC-ORDER THERMAL NITRIDATION OF SILICON AT LOW-TEMPERATURES, Journal of the Electrochemical Society, 145(12), 1998, pp. 4252-4256
Citations number
15
Categorie Soggetti
Electrochemistry,"Materials Science, Coatings & Films
Atomic-order nitridation of Si(100) in an NH3 environment (124-1400 Pa
) at 300-650 degrees C has been investigated using an ultraclean low p
ressure hot-wall reactor system. At 500 degrees C or higher, the N ato
m concentration (n(N)) initially increases and tends to saturate to a
certain value (d similar to 5 Angstrom, n(N) similar to 3 x 10(15) cm(
-2)). At 400 degrees C or lower, on the H-terminated Si surface, the S
i-hydride decreases with increasing NH3 exposure time and becomes hard
ly observed when n(N) reaches nearly to the surface Si atom concentrat
ion (6.8 x 10(14) cm(-2)). On the H-free Si surface, n(N) increases up
to similar to 2 x 10(14) cm(-2) with the appearance of the Si-hydride
instantly after NH3 exposure. It is expected that NH3 dissociatively
adsorbs on the Si dangling bonds. It is found that n(N), is well descr
ibed by Langmuir-type physical adsorption and reaction of NH3 on the S
i surface. The ultrathin nitride film shows Very good characteristics
as a mask against oxidation.