Effect of N sub(2O/SiH) sub(4) flow ratios on properties of amorphous silicon oxide thin films deposited by inductively-coupled plasma chemical vapor deposition with application to silicon surface passivation

• Published in: Vacuum 2009-11, Vol.84 (3), p.410-414
• Main Authors: Dao, Vinh-Ai, Nguyen, Van-Duy, Heo, Jongkyu, Choi, Hyungwook, Kim, Youngkuk, Lakshminarayan, Nariangadu, Yi, Junsin
• Format: Article
• Language: English
• Subjects: Density; Deposition; Nitrous oxides; Passivation; Silicon; Silicon dioxide; Silicon oxides; Thin films
• ISSN: 0042-207X
• DOI: 10.1016/j.vacuum.2009.09.002

Silicon oxide (SiO sub(x) thin films have been deposited at a substrate temperature of 300 degree C by inductively-coupled plasma chemical vapor deposition (ICP-CVD) using N) sub(2)O/SiH sub(4 plasma. The effect of N) sub(2)O/SiH sub(4 flow ratios on SiO) sub(x) film properties and silicon surface passivation were investigated. Initially, the deposition rate increased up to the N sub(2O/SiH) sub(4) flow ratio of 2/1, and then decreased with the further increase in N sub(2O/SiH) sub(4) flow ratio. Silicon oxide films with refractive indices of 1.47-2.64 and high optical band-gap values (3.3 eV) were obtained by varying the nitrous oxide to silane gas ratios. The measured density of the interface states for films was found to have minimum value of 4.3 x 10 super(11 eV) super(-)1 cm super(-2. The simultaneous highest tau ) sub(e)ff and lowest density of interface states indicated that the formation of hydrogen bonds at the SiO sub(x/c-Si interface played an important role in surface passivation of p-type silicon.)