Formation of silicon nitride films by remote plasma‐enhanced chemical vapour deposition

Abstract

In this paper we describe the growth of silicon nitride from nitrogen and silane for the first time by capacitively coupled remote PECVD. We report on the effect of process parameters on the composition and properties of the deposited films and we show that by adjustment of these parameters it is possible to produce high-quality material which could be of interest for electronic applications. Of particular note is that the growth rate is about one order of magnitude higher than any previously reported for nitride growth with remote PECVD using molecular nitrogen as the nitrogen source. We also discuss the mechanism of growth and propose that electron excitation of nitrogen and silane occurs in the gas phase, producing SiHx species which are adsorbed on the growing surface. The nitrogen is then incorporated into the layer by heterogeneous reaction. -

Atmospheric Plasma Deposition of Coatings Using a Capacitive Discharge Source

“…In low-pressure N 2 /SiH 4 plasmas, the hydrogen bonds to silicon and, in most cases, there is no detectable N±H. [82,94,95] By contrast, the N±H bonds dominate when ammonia is substituted for N 2 in the gas feed. [82,92,95] It has been shown that the conformality of silicon nitride films correlates with the hydrogen bond type.…”

Regularities of remote plasma enhanced chemical vapor deposition of silicon nitride films

“…1а). In a setup with capacitively coupled plasma, developed in [5] for deposition of silicon nitride films (Fig. 1b), the discharge region and the substrate in both reaction chambers are spacially separated.…”

“…Second, the total pressure controls the partial pressures of the starting reactants, and, therefore, increasing p tot drives homogeneous reactions of silane radicals with the starting SiH 4 [17]. Sufficiently high p tot not infrequently cause polymerization of silane radicals [5,15], as a result of which by-products deposit on the walls of the reaction chamber as a fine yellowish brown powder. Third, increased pressure hinders electron energy transport to the lower part of the reactor.…”

Remote PECVD : a Route to Controllable Plasma Deposition

“…In the majority of remote processes, RF power is coupled into the system inductively for excitation of some of initial reagents (see Figure 1). A schematic diagram of the experimental apparatus with capacitively coupled RF power, which was developed two years ago for formation of silicon nitride films [6], is shown in Figure 2. As one can see in both reaction chambers the plasma generation regions and the areas of reactors used for substrate location are separated in space.…”

“…A detailed discussion and interpretation of these two peaks has been given elsewhere [6]. From the intensities of these peaks the bonded hydrogen content in the deposited films was calculated.…”