Author Affiliations
Abstract
The comparison of domestic and foreign studies has been utilized to extensively employ junction termination extension (JTE) structures for power devices. However, achieving a gradual doping concentration change in the lateral direction is difficult for SiC devices since the diffusion constants of the implanted aluminum ions in SiC are much less than silicon. Many previously reported studies adopted many new structures to solve this problem. Additionally, the JTE structure is strongly sensitive to the ion implantation dose. Thus, GA-JTE, double-zone etched JTE structures, and SM-JTE with modulation spacing were reported to overcome the above shortcomings of the JTE structure and effectively increase the breakdown voltage. They provided a theoretical basis for fabricating terminal structures of 4H-SiC PiN diodes. This paper summarized the effects of different terminal structures on the electrical properties of SiC devices at home and abroad. Presently, the continuous development and breakthrough of terminal technology have significantly improved the breakdown voltage and terminal efficiency of 4H-SiC PiN power diodes.
PiN diode terminal structure mesa-JTE reverse breakdown voltage etching process Journal of Semiconductors
2023, 44(11): 113101
1 广东科技学院，广东东莞523083
2 华南理工大学 机械与汽车工程学院，广东广州510640
针对ITO玻璃表面线路激光刻蚀中因定位问题玻璃工件产生的微变形，采用微孔陶瓷对工件进行微气流阵列加压，确保高精度的激光刻蚀加工。分析不同加工工艺下的微气流压力分布，探究气流压力和刻蚀间隙对ITO玻璃刻蚀表面平面度的作用机制。结果表明：经微孔气流加压后，工件在气体流动的区域受到正压力，加工区域的压力分布较为均匀。由此可知，工件表面受到均布气压有利于刻蚀表面的定位，但过大的压力会导致工件微变形。实验结果显示：在合适的压力下，微孔气流加压可使得平面度低至8 μm，当压力在0.16~0.2 kPa，刻蚀间隙在1.8~1.9 mm时，工件表面压力为13.2~14.4 Pa，此时平面度最好，微米尺度的刻蚀线路清晰，不产生破损。最后，对微孔气流加压的ITO玻璃进行激光刻蚀加工，可得到8 μm以及25 μm的表面微细线路，解决了通常无微孔气流加压的刻蚀工艺导致局部断点或变形线路引起产品短路或开路等问题。
激光刻蚀 微孔气流 ITO玻璃 刻蚀工艺 高精密加工 laser etching microporous airflow ITO glass etching process high precision machining 光学 精密工程
2022, 30(13): 1564
1 长春理工大学 理学院 高功率半导体激光国家重点实验室, 长春 130022
2 中国科学院苏州纳米技术与纳米仿生研究所, 江苏 苏州 215123
针对光学倒锥窄尖的制备工艺困难的问题，通过特殊设计掩膜版，利用步进式光刻机，经过一次步进，对光刻胶进行两次连续的图案化处理，突破紫外光刻机的分辨率极限，制备出尖端接近50 nm的倒锥结构图案.再对光刻胶进行回流处理，解决其分层的问题，保证了结构侧壁的光滑度及尖端的完整性.在深硅刻蚀工艺中，通过对刻蚀中各气体组分进行调整，改善了锥形结构表面形貌，使结构的均匀性和完整性得到提升.最终得到了适用于层间耦合的尖端接近50 nm的光学倒锥.
光学倒锥 层间耦合 步进式光刻 光刻胶回流 刻蚀工艺 Optical inverted taper Interlayer coupling Step lithography Photoresist reflow Etching process 光子学报
2019, 48(12): 1223003
1 长春理工大学 理学院 高功率半导体激光国家重点实验室, 长春 130022
2 中国科学院苏州纳米技术与纳米仿生研究所, 江苏 苏州 215123
采用步进投影式光刻机的步进原理控制曝光剂量, 制备楔形模斑转换器.分析了不同曝光剂量对侧壁形貌的影响以及最佳的刻蚀参数.实验结果表明: 最佳曝光时间为20 ms/次, 回流温度为160℃, 时间为1 min, 当刻蚀气体及比例为SF6∶He=8∶80时, 刻蚀后得到满足需求的样品,且制备方式制作周期短, 精度高, 与电子束灰度曝光方法相比, 具有高效率、低成本等优点.
楔形 模斑转换器 步进式曝光 灰度 刻蚀工艺 Wedge-shaped Mode size converter Stepper exposure Gray scale Etching process
1 长春理工大学 理学院 高功率半导体激光国家重点实验室, 长春 130022
2 中国科学院苏州纳米技术与纳米仿生研究所, 江苏 苏州 215123
为了解决半导体激光器传统刻蚀工艺中侧壁陡直度差和器件难以重复制作的问题, 利用湿法腐蚀与干法刻蚀相结合的刻蚀手段, 对980 nm锥形半导体激光器刻蚀工艺进行优化.通过对台面粗糙度与刻蚀速度的研究, 确定湿法腐蚀液和浓度配比的差异.并分析电感耦合等离子刻蚀对脊波导与腔破坏凹槽表面形貌的影响.研究结果表明, 选择配比为NH3·H2O∶H2O2∶H2O=1∶1∶50的腐蚀液进行湿法腐蚀, 刻蚀速率约为7 nm/s, 速率容易控制.且样品表面具有较好的粗糙度和均匀性, 利用电感耦合等离子刻蚀得到的脊波导与腔破坏凹槽侧壁陡直度良好, 没有出现横向钻蚀的情况.
锥形半导体激光器 陡直度 刻蚀工艺 脊波导 腔破坏凹槽 Tapered semiconductor laser Steepness Etching process Ridge waveguide Cavity failure groove
Author Affiliations
Abstract
1 Higher Institute of Management Tunis, University of Tunis, Tunisia
2 Higher institute of Business and Accounting Bizerte, University of Carthage, Tunisia
Endpoint detection (EPD) is very important undertaking on the side of getting a good understanding and figuring out if a plasma etching process is done on the right way. It is truly a crucial part of supplying repeatable effects in every single wafer. When the film to be etched has been completely erased, the endpoint is reached. In order to ensure the desired device performance on the produced integrated circuit, many sensors are used to detect the endpoint, such as the optical, electrical, acoustical/vibrational, thermal, and frictional. But, except the optical sensor, the other ones show their weaknesses due to the environmental conditions which affect the exactness of reaching endpoint. Unfortunately, some exposed area to the film to be etched is very low (<0.5%), reflecting low signal and showing the incapacity of the traditional endpoint detection method to determine the wind-up of the etch process. This work has provided a means to improve the endpoint detection sensitivity by collecting a huge numbers of full spectral data containing 1201 spectra for each run, then a new unsophisticated algorithm is proposed to select the important endpoint traces named shift endpoint trace selection (SETS). Then, a sensitivity analysis of linear methods named principal component analysis (PCA) and factor analysis (FA), and the nonlinear method called wavelet analysis (WA) for both approximation and details will be studied to compare performances of the methods mentioned above. The signal to noise ratio (SNR) is not only computed based on the main etch (ME) period but also the over etch (OE) period. Moreover, a new unused statistic for EPD, coefficient of variation (CV), is proposed to reach the endpoint in plasma etches process.
Dimension reduction OES plasma etching process wavelet analysis CV SNR Photonic Sensors
2016, 6(2): 158
