scholarly journals Development of computer-controlled atmospheric pressure plasma structuring for 2D/3D pattern on fused silica

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Duo Li ◽  
Peng Ji ◽  
Yang Xu ◽  
Bo Wang ◽  
Zheng Qiao ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Mechanical Load ◽  
Removal Rate ◽  
Atmospheric Pressure Plasma ◽  
Fused Silica ◽  
Phase Plate ◽  
Gaussian Shape ◽  
Lens Array ◽  
Pressure Plasma ◽  
Computer Controlled

AbstractFused silica with structured and continuous patterns is increasingly demanded in advanced imaging and illumination fields because of its excellent properties and functional performance. Atmospheric pressure plasma, based on pure chemical etching under atmospheric pressure, is developed as a promising fabrication technique for fused silica due to its deterministic high material removal rate, controllable removal imprint and no mechanical load. The stable and controllable Gaussian-shape removal function makes computer-controlled plasma tool potential to generate complex structures with high accuracy, efficiency and flexibility. In the paper, computer-controlled atmospheric pressure plasma structuring (APPS) is proposed to fabricate 2D/3D patterns on fused silica optics. The capacitively coupled APPS system with a double-layer plasma torch and its discharge characteristics are firstly developed. By means of multi-physics simulation and process investigation, the stable and controllable Gaussian-shape removal function can be achieved. Two different structuring modes, including discrete and continuous APPS, are explored for 2D/3D patterns. A series of structuring experiments show that different kinds of 2D patterns (including square lens array, hexagon lens array and groove array) as well as complex 3D phase plate patterns have been successfully fabricated, which validates the effectiveness of the proposed APPS of 2D/3D patterns on fused silica optics.

Study of Form Control Algorithm in Atmospheric Pressure Plasma Processing

2014 ◽  
Vol 620 ◽  
pp. 49-54
Author(s):  
Duo Li ◽  
Bo Wang ◽  
Jun Wang ◽  
Qiang Xin
Keyword(s):  
Atmospheric Pressure ◽  
Dwell Time ◽  
Control Algorithm ◽  
Removal Rate ◽  
Ion Beam ◽  
Plasma Processing ◽  
Atmospheric Pressure Plasma ◽  
Fused Silica ◽  
Time Function ◽  
Pressure Plasma

Atmospheric Pressure Plasma Processing (APPP) has demonstrated that it can achieve high removal rate and induce no sub-surface damage on the silica based material of optical surface. Compared with traditional mechanical polishing and ion beam figuring, APPP technology is cost effective and very promising in the optics fabrication field. In principle, Atmospheric Pressure Plasma Processing can be described by the two-dimensional convolution equation with dwell time function and plasma removal function. Thus, dwell time function can be solved theoretically by the process of de-convolution, which is the essence of form control algorithm. First, this paper compares and analyzes common de-convolution algorithms by the simulated processing. From the simulation results, the algorithm based on the principle of image restoration has good solving speed, high calculation accuracy. Therefore, we choose it as the form control algorithm for Atmospheric Pressure Plasma Processing. However, the high temperature of plasma plume results in the non-linear relationship between the removal depth and time, further affecting the stability of the algorithm. Then, using the actual experiment data, we build the nonlinear relationship function model to compensate the heat effect in the algorithm. Finally, the modified algorithm is verified by the 7um uniform removal on the fused silica using Atmospheric Pressure Plasma Processing.

scholarly journals High-Accuracy Surface Topography Manufacturing for Continuous Phase Plates Using an Atmospheric Pressure Plasma Jet

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 683
Author(s):  
Huiliang Jin ◽  
Caixue Tang ◽  
Haibo Li ◽  
Yuanhang Zhang ◽  
Yaguo Li
Keyword(s):  
Surface Topography ◽  
Atmospheric Pressure ◽  
High Efficiency ◽  
Atmospheric Pressure Plasma ◽  
Plasma Jet ◽  
Continuous Phase ◽  
High Accuracy ◽  
Phase Plate ◽  
Atmospheric Pressure Plasma Jet ◽  
Pressure Plasma

The continuous phase plate (CPP) is the vital diffractive optical element involved in laser beam shaping and smoothing in high-power laser systems. The high gradients, small spatial periods, and complex features make it difficult to achieve high accuracy when manufacturing such systems. A high-accuracy and high-efficiency surface topography manufacturing method for CPP is presented in this paper. The atmospheric pressure plasma jet (APPJ) system is presented and the removal characteristics are studied to obtain the optimal processing parameters. An optimized iterative algorithm based on the dwell point matrix and a fast Fourier transform (FFT) is proposed to improve the accuracy and efficiency in the dwell time calculation process. A 120 mm × 120 mm CPP surface topography with a 1326.2 nm peak-to-valley (PV) value is fabricated with four iteration steps after approximately 1.6 h of plasma processing. The residual figure error between the prescribed surface topography and plasma-processed surface topography is 28.08 nm root mean square (RMS). The far-field distribution characteristic of the plasma-fabricated surface is analyzed, for which the energy radius deviation is 11 μm at 90% encircled energy. The experimental results demonstrates the potential of the APPJ approach for the manufacturing of complex surface topographies.

Dicing of SiC Wafer by Atmospheric-Pressure Plasma Etching Process with Slit Mask for Plasma Confinement

2014 ◽  
Vol 778-780 ◽  
pp. 759-762 ◽  
Author(s):  
Yasuhisa Sano ◽  
Hiroaki Nishikawa ◽  
Yuu Okada ◽  
Kazuya Yamamura ◽  
Satoshi Matsuyama ◽  
...  
Keyword(s):  
Plasma Etching ◽  
Atmospheric Pressure ◽  
Removal Rate ◽  
Atmospheric Pressure Plasma ◽  
Etching Process ◽  
Plasma Confinement ◽  
Plasma Etching Process ◽  
Pressure Plasma ◽  
High Removal Rate ◽  
Sic Wafer

Silicon carbide (SiC) is a promising semiconductor material for high-temperature, high-frequency, high-power, and energy-saving applications. However, because of the hardness and chemical stability of SiC, few conventional machining methods can handle this material efficiently. A plasma chemical vaporization machining (PCVM) technique is an atmospheric-pressure plasma etching process. We previously proposed a novel style of PCVM dicing using slit apertures for plasma confinement, which in principle can achieve both a high removal rate and small kerf loss, and demonstration experiments were performed using a silicon wafer as a sample. In this research, some basic experiments were performed using 4H-SiC wafer as a sample, and a maximum removal rate of approximately 10 μm/min and a narrowest groove width of 25 μm were achieved. We also found that argon can be used for plasma generation instead of expensive helium gas.

Polishing Characteristics of 4H-SiC Si-Face and C-Face by Plasma Chemical Vaporization Machining

2007 ◽  
Vol 556-557 ◽  
pp. 757-760
Author(s):  
Yasuhisa Sano ◽  
Masayo Watanabe ◽  
Kazuya Yamamura ◽  
Kazuto Yamauchi ◽  
Takeshi Ishida ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Etch Rate ◽  
Removal Rate ◽  
Atmospheric Pressure Plasma ◽  
Plasma Chemical ◽  
Machined Surface ◽  
Pressure Plasma ◽  
High Etch Rate ◽  
High Removal Rate ◽  
Conventional Machining

Silicon carbide (SiC) is a promising semiconductor material for power devices. However, it is so hard and so chemically stable that there is no efficient method of machining it without causing damage to the machined surface. Plasma chemical vaporization machining (PCVM) is plasma etching in atmospheric-pressure plasma. PCVM has a high removal rate equivalent to those of conventional machining methods such as grinding and lapping, because the radical density in atmospheric-pressure plasma is much higher than that in normal low-pressure plasma. In this paper, the polishing characteristics of SiC by PCVM are described. As a result of machining, the surface roughnesses of both Si- and C-faces were improved under a relatively low-etch-rate (100-200 nm/min) condition. The C-face was also improved under a relatively high-etch-rate (approximately 10 μm/min) condition, and a very smooth surface (below 2 nm peak-to-valley in a 500-nm-square area) was achieved.

Beveling of Silicon Carbide Wafer by Plasma Chemical Vaporization Machining

2008 ◽  
Vol 600-603 ◽  
pp. 843-846 ◽  
Author(s):  
Takehiro Kato ◽  
Yasuhisa Sano ◽  
Hideyuki Hara ◽  
Hidekazu Mimura ◽  
Kazuya Yamamura ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Atmospheric Pressure ◽  
Removal Rate ◽  
Atmospheric Pressure Plasma ◽  
High Hardness ◽  
Wafer Surface ◽  
Plasma Chemical ◽  
Pressure Plasma ◽  
Surface Polishing ◽  
High Removal Rate

Beveling is essential for preventing the chipping of the edge of a wafer during surface polishing and other processes. Plasma chemical vaporization machining (PCVM) is an atmospheric-pressure plasma etching process. It has a high removal rate equivalent to those of conventional machining methods such as grinding and lapping, which are used for high-hardness materials such as silicon carbide, due to the generation of high-density radicals in atmospheric-pressure plasma. Furthermore, PCVM does not damage the wafer surface because it is a purely chemical process; therefore, it is considered that PCVM can be used as an effective method of beveling the edge of SiC wafers. In this paper, we report the investigation of the beveling of SiC wafers by PCVM.

Back-Side Thinning of Silicon Carbide Wafer by Plasma Etching Using Atmospheric-Pressure Plasma

2012 ◽  
Vol 516 ◽  
pp. 108-112 ◽  
Author(s):  
Yasuhisa Sano ◽  
Kohei Aida ◽  
Hiroaki Nishikawa ◽  
Kazuya Yamamura ◽  
Satoshi Matsuyama ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Plasma Etching ◽  
Atmospheric Pressure ◽  
Removal Rate ◽  
Thickness Distribution ◽  
Atmospheric Pressure Plasma ◽  
Back Side ◽  
Wafer Level ◽  
Pressure Plasma ◽  
Sic Wafer

Silicon carbide (SiC) power devices have received much attention in recent years because they enable the fabrication of devices with low power consumption. To reduce the on-resistance in vertical power transistors, back-side thinning is required after device processing. However, it is difficult to thin a SiC wafer with a high removal rate by conventional mechanical machining because its high hardness and brittleness cause cracking and chipping during thinning. In this study, we attempted to thin a SiC wafer by plasma chemical vaporization machining (PCVM), which is plasma etching using atmospheric-pressure plasma. The wafer level thinning of a 2-inch 4H-SiC wafer has been possible without a removal thickness distribution caused by the circular shape of the wafer using the newly developed PCVM apparatus for back-side thinning with a spatial wafer stage.

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