Park Yoonsoo, Lim Hyuna, Baek Namwuk, Park Seung Hun, Lee Sungwoo, Yang Jeayoung, Jung Donggeun
Department of Physics, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
Advanced Research Laboratory, TES Co., Yongin 17162, Republic of Korea.
J Nanosci Nanotechnol. 2021 Aug 1;21(8):4470-4476. doi: 10.1166/jnn.2021.19416.
In semiconductor industry, low-dielectric-constant SiCOH films are widely used as inter-metal dielectric (IMD) material to reduce a resistance-capacitance delay, which could degrade performances of semiconductor chips. Plasma enhanced chemical vapor deposition (PECVD) system has been employed to fabricate the low-dielectric-constant SiCOH films. In this work, among various parameters (plasma power, deposition pressure, substrate temperature, precursor injection flow rate, etc.), helium carrier gas flow rate was used to modulate the properties of the low-dielectric-constant SiCOH films. Octamethylcyclotetrasiloxane (OMCTS) precursor and helium were injected into the process chamber of PECVD. And then SiCOH films were deposited varying helium carrier gas flow rate. As helium carrier gas flow rate increased from 1500 to 5000 sccm, refractive indices were increased from 1.389 to 1.428 with enhancement of mechanical strength, i.e., increased hardness and elastic modulus from 1.7 and 9.1 GPa to 3.3 and 19.8 GPa, respectively. However, the relative dielectric constant () value was slightly increased from 2.72 to 2.97. Through analysis of Fourier transform infrared (FTIR) spectroscopy, the effects of the helium carrier gas flow rate on chemical structure, were investigated. It was thought that the increase in helium carrier gas flow rate could affect the density with changes of chemical structure and composition. In conclusion, regulation of helium carrier gas flow rate can effectively modulate values and mechanical strength, which is needed for IMD material in semiconductor fabrication possess.
在半导体工业中，低介电常数的SiCOH薄膜被广泛用作金属间介质（IMD）材料，以减少电阻 - 电容延迟，这种延迟会降低半导体芯片的性能。等离子体增强化学气相沉积（PECVD）系统已被用于制备低介电常数的SiCOH薄膜。在这项工作中，在各种参数（等离子体功率、沉积压力、衬底温度、前驱体注入流速等）中，氦载气流量被用来调节低介电常数SiCOH薄膜的性能。八甲基环四硅氧烷（OMCTS）前驱体和氦气被注入到PECVD的工艺腔室中。然后在不同的氦载气流量下沉积SiCOH薄膜。随着氦载气流量从1500 sccm增加到5000 sccm，折射率从1.389增加到1.428，同时机械强度增强，即硬度和弹性模量分别从1.7 GPa和9.1 GPa增加到3.3 GPa和19.8 GPa。然而，相对介电常数（）值从2.72略微增加到2.97。通过傅里叶变换红外（FTIR）光谱分析，研究了氦载气流量对化学结构的影响。据认为，氦载气流量的增加会随着化学结构和组成的变化影响密度。总之，调节氦载气流量可以有效地调节值和机械强度，这是半导体制造中IMD材料所需要具备的。
