Center for Nanoscale Science and Engineering, North Dakota State University, Research Park Drive, Fargo, North Dakota 58102, USA. guruvenket.srinivasan@ndsu
ACS Appl Mater Interfaces. 2012 Oct 24;4(10):5293-9. doi: 10.1021/am301157p. Epub 2012 Sep 28.
Atmospheric pressure plasma enhanced chemical vapor deposition (AP-PECVD) using Surfx Atomflow(TM) 250D APPJ was utilized to synthesize amorphous silicon carbonitride coatings using tetramethyldisilizane (TMDZ) and hexamethyldisilizane (HMDZ) as the single source precursors. The effect of precursor chemistry and substrate temperature (T(s)) on the properties of a-SiCN:H films were evaluated, while nitrogen was used as the reactive gas. Surface morphology of the films was evaluated using atomic force microscopy (AFM); chemical properties were determined using Fourier transform infrared spectroscopy (FTIR); thickness and optical properties were determined using spectroscopic ellipsometry and mechanical properties were determined using nanoindentation. In general, films deposited at substrate temperature (T(s)) < 200 °C contained organic moieties, while the films deposited at T(s) > 200 °C depicted strong Si-N and Si-CN absorption. Refractive indices (n) of the thin films showed values between 1.5 and 2.0, depending on the deposition parameters. Mechanical properties of the films determined using nanoindentation revealed that these films have hardness between 0.5 GPa and 15 GPa, depending on the T(s) value. AFM evaluation of the films showed high roughness (R(a)) values of 2-3 nm for the films grown at low T(s) (<250 °C) while the films grown at T(s) ≥ 300 °C exhibited atomically smooth surface with R(a) of ~0.5 nm. Based on the gas-phase (plasma) chemistry, precursor chemistry and the other experimental observations, a possible growth model that prevails in the AP-PECVD of a-SiCN:H thin films is proposed.
采用 Surfx Atomflow(TM) 250D APPJ 的大气压等离子体增强化学气相沉积 (AP-PECVD)，使用四甲基二硅氮烷 (TMDZ) 和六甲基二硅氮烷 (HMDZ) 作为单源前体合成非晶碳氮化硅 (a-SiCN:H) 薄膜。评估了前驱体化学和基底温度 (T(s)) 对 a-SiCN:H 薄膜性能的影响，同时使用氮气作为反应气体。使用原子力显微镜 (AFM) 评估薄膜的表面形貌；使用傅里叶变换红外光谱 (FTIR) 确定化学性质；使用光谱椭圆偏振法确定厚度和光学性质；使用纳米压痕法确定力学性质。一般来说，沉积在基底温度 (T(s)) < 200°C 的薄膜含有有机基团，而沉积在 T(s) > 200°C 的薄膜显示出强的 Si-N 和 Si-CN 吸收。薄膜的折射率 (n) 根据沉积参数在 1.5 到 2.0 之间。使用纳米压痕法确定的薄膜力学性能表明，这些薄膜的硬度在 0.5 GPa 到 15 GPa 之间，取决于 T(s) 值。AFM 对薄膜的评估表明，沉积在低 T(s) (<250°C) 的薄膜具有 2-3nm 的高粗糙度 (R(a)) 值，而沉积在 T(s) ≥ 300°C 的薄膜具有原子级光滑表面，R(a)约为 0.5nm。基于气相 (等离子体) 化学、前驱体化学和其他实验观察结果，提出了一种适用于 AP-PECVD 生长 a-SiCN:H 薄膜的可能生长模型。
