Chemical vapor deposition of SiC at different molar ratios of hydrogen to methyltrichlorosilane

Abstract

Chemical vapor deposition (CVD) of SiC from methyltrichlorosilane (MTS) was studied at two different molar ratios of H 2 to MTS (n(H 2 )/n(MTS)). The total pressure was kept as 100 kPa and the temperature was varied from 850 to 1 100 at ℃ a total residence time of 1 s. Steady-state deposition rates as functions of reactor length and of temperature, investigated at different n(H 2 )/n(MTS) values, show that hydrogen exhibits strongly influences on the deposition rate. Especially, the deposition of Si co-deposit can be obtained in broader substrate length and at higher temperatures with increasing hydrogen partial pressure. Influence of hydrogen on the deposition process was also studied using gas phase composition and deposit composition analysis at various n(H 2 )/n(MTS). SEM micrographs directly show the variation of surface morphologies at various n(H 2 )/n(MTS). It can be found that the crystal grain of the deposit at 1 100 is better developed and the crystallization is also improved with increasing ℃ n(H 2 )/n(MTS).

Transient stages during the chemical vapour deposition of silicon carbide from CH3SiCl3/H2: impact on the physicochemical and interfacial properties of the coatings

“…From the early times to very recently, theoretical -thermodynamic and kinetic-approaches have been proposed to describe the homogeneous reactions taking place in the reactor and the nature of the gas species, particularly of the effective precursors of the Si-C solid [13][14][15][16][17][18][19][20][21]. In parallel, experimental studies have been conducted to investigate the influence of the CVD parameters on the growth rate [23-34, 36-46, 48-49], the composition of the gas phase (in situ or downstream of the reactor) [6][7][8][9][10][11][12]48], the nature (i.e. the stoichiometry and the structure) of the deposited solid [10-11, 27, 30, 32, 34-35, 37-42, 45-49] and even its mechanical properties [22][23].…”

Kinetic and gas-phase study of the chemical vapor deposition of silicon carbide from C2H3SiCl3/H2

“…The latter effect is due to the inhibition of the silicon adsorption sites by chlorine blockage [13]. It has often been mentioned in CVD studies of the MTS/H2 system [8,9,12,29] and described by modelling [47]. It could also explain the decrease of the deposition rate observed in the CRR2 regime (at T = 1000 °C) after the addition of SiHCl3 in the VTS/H2 mixture (Fig.…”

“…This process often leads to some silicon excess at low temperature and low gas residence time [4,5], leading to a decrease of the lifetime of the final material [6]. Previous works from the literature mentioned that both the high reactivity of chlorosilanes and the low reactivity of hydrocarbons formed in the gas phase at low temperature could explain the low carbon content in the deposit [4,[7][8][9][10]. Some authors have proposed to add HCl in order to promote silicon etching [17,[11][12][13].…”

Surface Kinetic Mechanisms of Epitaxial Chemical Vapour Deposition of 4H Silicon Carbide Growth by Methyltrichlorosilane-H2 Gaseous System

“…Besides, an alternative chlorinated compound, methyltrichlorosilane (CH 3 SiCl 3 , MTS), which contains not only Si and C but also Cl, is commercially used as a precursor for silicon carbide with a wide range of allowable deposition temperatures [ 26 , 27 , 28 , 29 , 30 ], and its decomposition is catalyzed by hydrogen, the carrier gas [ 31 ]. MTS will decompose in the CVD reactor to form intermediate species containing silicon, carbon and chlorine, and some of these intermediate species contribute greatly to form the SiC film by participating in surface reactions on the substrate.…”