Fabrication of sin thin films by rf biased microwave plasma CVD

Abstract

The purpose of this study is to clarify the effect of ion bombardment during the deposition of silicon nitride film. Since silicon nitride is an insulator, ion bombardment was controlled by RF bias to the substrate. When the effective value of the RF voltage was increased from 0 to 120 V, the self‐bias, which is an indicator of the acceleration voltage of ions is impinging on the film, monotonically changed from 0 to −75 V. Therefore, when RF voltage is increased, the ion bombardment increased, hydrogen content in the film decreased, the content of nitrogen and silicon in the film increased, and the film density increased. This phenomenon is caused by the acceleration of surface reaction due to the thermal effect on the film surface by the increase of ion bombardment. The Si/N ratio was constant regardless of the RF voltage.

Effect of DC Bias Voltage on the Characteristics of Low Temperature Silicon–Nitride Films Deposited by Internal Linear Antenna Inductively Coupled Plasma Source

“…3) In this case, film formation takes place as a result of the reactions between a number of exited species such as N, NH x , and SiH x . 4) In addition, by the application of a plasma during the CVD, that is, by using plasma enhanced CVD (PECVD), silicon nitride can be deposited at a lower temperature ($300 C), [5][6][7] whereas it is deposited at a temperature of $800 C in the case of LPCVD. 8) However, the deposition of silicon nitride at a lower temperature by using conventional PECVD shows some problems, such as poor nitride/Si interface properties and a high bulk trap density in the silicon nitride film, causing the degradation of the electric properties of the devices, in addition to the presence of hydrogen in the film.…”

Si 3 N 4 on GaAs by direct electron cyclotron resonance plasma assisted nitridation of Si layer in Si/GaAs structure

“…1-3 For example, thermal nitridation of pre-deposited silicon, 4 only possible at temperatures higher than 1000°C, and chemical vapor deposition ͑CVD͒ using silane and ammonia at 700-900°C 5,6 would both result in arsenic loss and a consequent increase in dangling bonds at the interface. 11 In this article, we report on an improved approach in which a GaAs surface was coated with a thin layer of Si which was subsequently converted to Si 3 N 4 by RPECVD nitridation. [7][8][9] Unfortunately, energetic species from the plasma are likely to have damaged the GaAs surface, and again the interface was found to have degraded.…”

Fabrication of SiN films at low temperature by RF biased coaxial‐line microwave plasma CVD

“…Since SiN film is an insulating material, the film is charged if a DC bias is applied. Therefore, in this study, the RF bias method is used [8,9]. The substrate temperatures are room temperature and 200°C.…”

“…21 .O MHz RF energy is fed to the stainless steel substrate table in the deposition chamber (ID = 25.4 cm) via a matching circuit; the substrate table (4.5 cm x 1 1 cm) is electrically isolated from the deposition chamber. Because the RF biased substrate table is placed in the spatial afterglow plasma region, the plasma condition does not change even though the substrate table is RF-biased [8,9]. The RF bias is a self-bias which is generated at the substrate table when RF power is applied.…”