Paper TF-ThP16
Effect of DC bias on the Characteristics of Low Temperature Silicon-Nitride Films Deposited by Internal Linear Inductively Coupled Plasma Source

Thursday, November 12, 2009, 6:00 pm, Room Hall 3

There has been a growing interest in the dielectric material that can be deposited at low substrate temperatures for the applications such as organic devices and flexible display devices. Of diverse dielectric materials, silicon-nitride film has been widely used for various important applications from semiconductor to flat panel display, such as a gate dielectric material for thin film transistor (TFT), passivation layers for diverse microelectronics and as anti-reflection (AR) coating for solar cell. In addition, due to their chemical inertness, excellent dielectric properties, and thermal stability compared with those of silicon oxide, many researchers have been studied to develop high quality low temperature silicon-nitride films using various types of plasma sources. Generally, conventional technique for depositing SiN at a low temperature is plasma-Enhanced CVD (PECVD) (~300℃).

In this study, we carried out the deposition of silicon nitride thin films at the temperature lower than 100℃ by using an internal linear ICP source. To obtain high quality silicon-nitride films, the effects of the ratio of NH₃ to SiH₄ and DC bias on the properties of thin film were investigated. The results showed that, by using 2:1 ratio of NH₃:SiH, and by using -150V DC bias, the high quality silicon nitride film having the refractive index of 1.83, dielectric constant of 7.2 with negligible interface traps could be observed. The compositions, binding states, and the refractive indices of the films were measured using a XPS, FTIR, and an ellipsometer, respectively. In addition, metal/insulator/semiconductor (MIS) capacitors having Al/insulator/p-Si were fabricated and the flat-band voltage and hysteresis voltage were measured by the capacitance-voltage (C-V) method.