Deposition of device quality silicon nitride with ultra high deposition rate (>7 nm/s) using hot-wire CVD

Abstract

The application of hot-wire (HW) CVD deposited silicon nitride (SiN x ) as passivating anti-reflection coating on multicrystalline silicon (mc-Si) solar cells is investigated. The highest efficiency reached is 15.7% for SiN x layers with an N/Si ratio of 1.20 and a high mass density of 2.9 g/cm 3 . These cell efficiencies are comparable to the reference cells with optimized plasma enhanced (PE) CVD SiN x even though a very high deposition rate of 3 nm/s is used. Layer characterization showed that the N/Si ratio in the layers determines the structure of the deposited films. And since the volume concentration of Si-atoms in the deposited films is found to be independent of the N/Si ratio the structure of the films is determined by the quantity of incorporated nitrogen. It is found that the process pressure greatly enhances the efficiency of the ammonia decomposition, presumably caused by the higher partial pressure of atomic hydrogen. With this knowledge we increased the deposition rate to a very high 7 nm/s for device quality SiN x films, much faster than commercial deposition techniques offer [S. von Aichberger, Photon Int. 3 (2004) 40].

The effect of composition on the bond structure and refractive index of silicon nitride deposited by HWCVD and PECVD

“…SiN x films were deposited using Hot Wire (HW) CVD [1], radio frequency (RF) plasma enhanced (PE) CVD [2], pulsed low frequency (LF) PECVD [3] and microwave (MW) PECVD [4]. The composition of the films was varied by adjusting the silane to ammonia flow ratio, except for the LF PECVD films where only the substrate temperature was altered.…”

Deposition of silicon nitride thin films by hot-wire CVD at 100 °C and 250 °C

“…Several groups have shown that the Hot-wire chemical vapor deposition technique, HWCVD, presented clear advantages over plasma-assisted deposition techniques for SiN x deposition [6][7][8].…”

Investigation of structural properties of high‐rate deposited SiNx films prepared at low temperatures (100–300 °C) by atmospheric‐pressure plasma CVD

“…As a result, a SiN x film with reasonabe quality is obtained at 300 °C despite the very high deposition rate. However, the film density is still lower than that of the device-quality films formed by a hot-wire CVD method [24]. Besides, the decrease in T sub causes a further deterioration of film quality as shown in Fig.…”