Surface passivation of n-type crystalline Si by plasma-enhanced-chemical-vapor-deposited amorphous SiCx:H and amorphous SiCxNy:H films

Abstract

Excellent passivation of n-type crystalline silicon surface is demonstrated by means of intrinsic amorphous silicon carbide (a-SiCx:H) thin films. An optimum CH4/SiH4 ratio is determined, leading to an effective surface recombination velocity, Seff, lower than 54 cm s−1. By adding a constant flow of N2 to the precursor gases, the surface passivation is improved to Seff⩽16 cm s−1. From infrared spectroscopy measurements of these films, it can be deduced that the N2 flow increases the carbon content of the layers for a constant CH4/SiH4 ratio. The dependence of the effective lifetime, τeff, on the excess charge carrier density, Δn, is measured using the quasisteady-state photoconductance technique, and these curves are simulated through an electrical model based on an insulator/semiconductor structure.

Effect of Porogen Incorporation on Pore Morphology of Low-k SiCxNyFilms Prepared Using PECVD

“…• C. 11 These asdeposited films also possess low film density of 1.6-2.0 g/cm 3 , which can be attributed to the existence of micropores, but limited porosity, in the as-deposited SiC x N y films due to the induced pores resulting from organic phase and the formation of Si-(CH 2 ) n -Si with the matrix structure. 12 In order to explore and fabricate porous SiC x N y films with higher porosity, a sacrificial porogen, epoxycyclohexane (ECH) as illustrated in Fig.…”

“…A conservative approach was proposed by Nguyen et al, 7 who prepared a dielectric barrier bilayer of dense SiN y /porous SiC x N y , exhibiting 12% porosity, by performing plasma deposition of dimethylsilacyclopentane and NH 3 and then using UV to cure the samples. The dense films of the bilayer on top helped protect the underlying copper layer against plasma-induced damage and oxidation caused by the diffusion of oxygen, whereas the bottom porous film of the bilayer contributed to a reduction in the dielectric constant.…”

“…10 1,3,5-trimethyl-1,3,5-trivinylcyclotrisilazane (VSZ), a cyclic organosilazane with 3 vinyl side-groups as illustrated in Fig. 1a, has been used as the single source precursor for depositing low-k SiC x N y by using PECVD and a low power density (0.15 W/cm 3 ) to obtain SiC x N y films of low dielectric constant ranging between 3.6 and 4.6 z E-mail: jimleu@mail.nctu.edu.tw for deposition temperatures ranging from 25 to 400…”

“…1 Silicon carbonitride films are typically prepared by performing plasma-enhanced chemical vapor deposition (PECVD) of multi-precursors such as silane/ammonia (or nitrogen)/methane 2,3 and trimethylsilane/amonia. 4 Recently, single source precursors such as hexamethyldisilazane 5 and BASICN 6 have been used for preparing dense low-k SiC x N y films by using PECVD because these films display low defects (i.e., low leakage current) and higher etch selectivity due to high C/Si ratio.…”

Hydrogen-free SiCN Films Obtained by Electron Cyclotron Resonance Plasma

“…1,2 A number of different techniques, such as ion implantation, 3,4 chemical vapor deposition, [5][6][7][8][9][10][11][12][13][14][15][16] or sputtering, 17 among others, have been employed to obtain this material, since Gómez et al suggested the possible miscibility of ␤-Si 3 N 4 and the hypothetical one, ␤-C 3 N 4 . 18 The optical properties of SiCN suggest the behavior as a wide-bandgap semiconductor in the case of the crystalline phase, with potential applications for blue or ultraviolet optoelectronic devices.…”