PECVD Synthesis of Silicon Carbonitride Layers Using Methyltris(diethylamino)silane as the New Single-Source Precursor

Abstract

Deposition of thin SiC x N y layers from a new single-source organosilicon compound, methyltris(diethylamino)silane (MTDEAS) mixed with helium or nitrogen is studied by using thermodynamic simulation of Si-C-N-H(He)-O system and experimentally by low pressure (10 −2 -10 Torr) plasma enhanced chemical vapor decomposition (PECVD) in the temperature range of 300-1300 K. Thermodynamic simulation allowed to find the temperature boundaries of solid phase formation. The phase composition, as well as physicochemical and functional properties of the layers has been studied using a complex of modern experimental techniques, including Raman spectroscopy, scanning electron (SEM) and atomic force microscopy (AFM), X-ray diffraction using synchrotron radiation (XRD-SR), ellipsometry and spectrophotometry. The electrophysical parameters were measured using the C-V characteristics. The microhardness and Young's modulus were determined by Nanoindentation method. It was shown that the layers contain crystals of phases belonging to Si 3-x C x N 4 structures, such as α-Si 3 N 4 , α-Si 2 CN 4 , α-SiC 2 N 4 , and α-C 3 N 4 which, possibly, are embedded in the amorphous matrix of silicon carbonitride layers.

Selective Gas-Phase Functionalization of SiO2 and SiNx Surfaces with Hydrocarbons

“…54,57 The large increase in absorbance from ∼2650−3000 cm −1 is broadly assigned to the −CH 3 and −CH 2 asymmetric and symmetric stretching vibrations of the C−H bonds. 55,58 Of particular interest is the appearance of a shoulder at ∼2790 cm −1 , which indicates the presence of a −CH 3 group back-bonded to N (NH−CH 3 ) which redshifts the C−H stretching frequency compared to −CH 3 back-bonded to C. 38 This redshifted feature in the infrared spectrum indicates that the surface is terminated in a secondary amine (see Figure 3b). A slight increase in absorbance is also observed at ∼3250 cm −1 , which is assigned to >NH stretching vibrations, 44,59 which further confirms secondary amine surface termination.…”

“… As expected, in Figure a, we can observe a large increase in absorbance at ∼1070 cm –1 , which indicates that Si–O–Si bridges are formed on the SiO 2 surface. The sharp increase at ∼1270 cm –1 is identified as the deformation mode of −CH 3 back-bonded to Si (Si–CH 3 ). ,− The vibrational modes from ∼1340 to 1470 cm –1 are assigned to a combination of both the −CH 2 – and −CH 3 asymmetric and symmetric deformation modes in the carbon backbone (see Figure b). , The large increase in absorbance from ∼2650–3000 cm –1 is broadly assigned to the −CH 3 and −CH 2 asymmetric and symmetric stretching vibrations of the C–H bonds. , Of particular interest is the appearance of a shoulder at ∼2790 cm –1 , which indicates the presence of a −CH 3 group back-bonded to N (NH–CH 3 ) which redshifts the C–H stretching frequency compared to −CH 3 back-bonded to C . This redshifted feature in the infrared spectrum indicates that the surface is terminated in a secondary amine (see Figure b).…”

Hard silicon carbonitride thin‐film coatings by remote hydrogen plasma chemical vapor deposition using aminosilane and silazane precursors. 2: Physical, optical, and mechanical properties of deposited films

“…It is worth mentioning that the refractive index values reported for a‐SiCN films produced by (DP‐CVD) from TMDSN, [ 34 ] HMDSN, [ 34 ] methyltris(diethylamino)silane, [ 45 ] and divinyltetramethyldisilazane, [ 46 ] are: n = 2.1–2.3 [ 34 ] , n = 1.5–2.1 [ 45 ] ( T S = 200–400°C), and n = 1.5–1.9 [ 46 ] ( T S = 250–400°C), respectively.…”

“…The optical bandgap reported for a‐SiCN films produced by DP‐CVD from TMDSN, [ 48 ] HMDSN, [ 48 ] and methyltris(diethylamino)silane, [ 45 ] were E o = 2.5–5.0 eV, [ 48 ] E o = 2.0–4.3 eV, [ 48 ] and E o = 0.7–2.8, [ 45 ] respectively.…”

Hard silicon carbonitride thin‐film coatings produced by remote hydrogen plasma chemical vapor deposition using aminosilane and silazane precursors. 1: Deposition mechanism, chemical structure, and surface morphology

“…It is interesting to compare our AFM data with those reported in the literature on silicon carbonitride films deposited on c‐Si wafers from organosilicon precursors by other CVD methods. For example, a‐SiCN films produced by DP‐CVD using bis(trimethylsilyl)carbodiimide, [ 53 ] tris(diethylamino)methylsilane, [ 54 ] and hexamethyldisilazane [ 55,56 ] exhibited much rougher surfaces with the roughness varying in the following ranges: R rms = 3–5 nm, [ 53 ] R rms = 5–7 nm, [ 54 ] and R rms = 2–14 nm. [ 55,56 ] A much smoother surface was obtained by film deposition on the negatively biased substrate during the DP‐CVD process.…”