Plasma-assisted polishing for atomic surface fabrication of single crystal SiC

Abstract

At present, owing to the inherent limitations of the material characteristics of Si based semiconductor materials, Si based semiconductors are facing more and more challenges in meeting the performance requirements of the rapidly developing modern power electronic technologies used in semiconductor devices. As a new generation of semiconductor material, SiC has significant performance advantages, but it is difficult to process the SiC wafers with high-quality and high-efficiency in their industrial application. Reviewing the research progress of ultra-precision machining technology of SiC in recent years, we introduce plasma oxidation modification based highly efficient polishing technology of SiC in this paper. The material removal mechanism, typical device, modification process, and polishing result of this technology are analyzed. The analysis shows that the plasma oxidation modification possesses high removal efficiency and atomically flat surfaces without surface or subsurface damages. Furthermore, aiming at step-terrace structures produced during SiC surface processing with different polishing technologies, the generation mechanism and control strategy of periodic atomic layer step-terrace structures are discussed. Finally, the development and challenge of plasma-assisted polishing technology are prospected.

Energy beam-based direct and assisted polishing techniques for diamond: A review

“…As shown in figure 23(d), the MRR of SiC surface with water vapor as the reaction gas is significantly higher than that with O 2 as the reaction gas. Since the oxidation potential of OH radicals (2.80 V) is greater than that of O radicals (2.42 V) [131], the MRR with water vapor as the reaction gas is higher than that with O 2 as the reaction gas.…”

“…This is because the ablation rate of ECR plasma in this experiment is lower than the graphitization rate of diamond, so there is residual graphite on the surface after etching. [131]. Reproduced with permission from [131].…”

“…Since the emergence of PAP technology, its material removal mechanism has received considerable research attention. Deng and Ji et al [130,131] proposed the principle of PAP for SiC. As shown in figure 15, the SiC surface is first irradiated with atmospheric plasma.…”

“…Many types of gases can be used as the reaction gas for PAP, but the oxidizing strength of free radicals generated by the ionization of different gases varies. Deng et al [130,131] used optical emission spectroscopy to compare the free radicals in two plasmas when the reaction gas was either water vapor or O 2 . As illustrated in figures 23(a) and (b), a strong signal of OH radicals (λ = 309 nm) is observed when water vapor is used as the reaction gas [151], and a strong signal of O free radicals (λ = 777 nm and λ = 845 nm) is observed when the reaction gas is O 2 [152].…”

Study on Improving the Precise Machinability of Single Crystal SiC by an Ultrasonic-Assisted Hybrid Process

“…Therefore, domestic and foreign scholars in the field of precise machining have put forward many hybrid machining methods by introducing the external energy field. Electrochemical mechanical polishing (ECMP) [ 8 , 9 ], plasma-assisted polishing [ 10 , 11 ], UV (ultraviolet) photocatalytic-assisted polishing [ 12 , 13 ], laser-induced assisted polishing [ 14 , 15 ], and Fenton oxidation-assisted polishing [ 16 ] were included. In essence, these methods improved the oxidation corrosion performance of SiC by different external energies, which made the material easy to be removed.…”