Study of dry etched N-polar (Al)GaN surfaces obtained by inductively coupled plasma etching
We report the Cl-based inductively coupled plasma etching of N-polar Al(Ga)N layers obtained from layer transfer. It is found that debris appeared on the etched N-polar surface after exposing in air for a short period whereas the etched Al-/Ga-polar surface was clean and smooth. The debris can be co...
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| Format: | Article |
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Frontiers Media S.A.
2022-10-01
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| Series: | Frontiers in Physics |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fphy.2022.1042998/full |
| _version_ | 1811234703840116736 |
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| author | Xiaoming Ge Xuebing Yin Qiaoyu Zeng Qi Feng Xiaohui Wang Quantong Li Zhitao Chen Chengguo Li |
| author_facet | Xiaoming Ge Xuebing Yin Qiaoyu Zeng Qi Feng Xiaohui Wang Quantong Li Zhitao Chen Chengguo Li |
| author_sort | Xiaoming Ge |
| collection | DOAJ |
| description | We report the Cl-based inductively coupled plasma etching of N-polar Al(Ga)N layers obtained from layer transfer. It is found that debris appeared on the etched N-polar surface after exposing in air for a short period whereas the etched Al-/Ga-polar surface was clean and smooth. The debris can be completely self-vanished on the N-polar Al0.4Ga0.6N surface after exposing in air for a few hours but still remained on the N-polar GaN surface even after over 1 month. The surface chemical analysis results suggested that the debris is the result of Cl-related byproduct generated during the etching process. Byproducts like Al(Ga)Clx and its derivatives are believed to cover on the N-polar surface after the inductively coupled plasma etching and increase the etched surface roughness significantly. The formation and disappearance of debris are attributed to the formation of Al(Ga)Clx⋅ 6H2O crystals when Al(Ga)Clx absorbs moisture in the air and its spontaneous decomposition on the N-polar surface, respectively. Adding O2/SF6 in the process helps remove Al(Ga)Clx byproducts but at the cost of roughened surface/reduced etch rate. With an additional cleaning process after etching, an uniform and smooth N-polar GaN surface with a low root-mean-square surface roughness of 0.5–0.6 nm has been successfully obtained at a reasonable etch rate (∼150 nm/min). The results can provide valuable guidance for the fabrication of high-performance N-polar GaN devices. |
| first_indexed | 2024-04-12T11:41:15Z |
| format | Article |
| id | doaj.art-d17294de167340448ff803ee58ad5736 |
| institution | Directory Open Access Journal |
| issn | 2296-424X |
| language | English |
| last_indexed | 2024-04-12T11:41:15Z |
| publishDate | 2022-10-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Physics |
| spelling | doaj.art-d17294de167340448ff803ee58ad57362022-12-22T03:34:39ZengFrontiers Media S.A.Frontiers in Physics2296-424X2022-10-011010.3389/fphy.2022.10429981042998Study of dry etched N-polar (Al)GaN surfaces obtained by inductively coupled plasma etchingXiaoming Ge0Xuebing Yin1Qiaoyu Zeng2Qi Feng3Xiaohui Wang4Quantong Li5Zhitao Chen6Chengguo Li7Institute of Semiconductors, Guangdong Academy of Sciences GuangzhouGuangzhouChinaInstitute of Semiconductors, Guangdong Academy of Sciences GuangzhouGuangzhouChinaInstitute of Semiconductors, Guangdong Academy of Sciences GuangzhouGuangzhouChinaSongshan Lake Materials Laboratory, Songshan Lake Innovation and Entrepreneurship Community City A1, Dongguan, ChinaSongshan Lake Materials Laboratory, Songshan Lake Innovation and Entrepreneurship Community City A1, Dongguan, ChinaInstitute of Semiconductors, Guangdong Academy of Sciences GuangzhouGuangzhouChinaInstitute of Semiconductors, Guangdong Academy of Sciences GuangzhouGuangzhouChinaInstitute of Semiconductors, Guangdong Academy of Sciences GuangzhouGuangzhouChinaWe report the Cl-based inductively coupled plasma etching of N-polar Al(Ga)N layers obtained from layer transfer. It is found that debris appeared on the etched N-polar surface after exposing in air for a short period whereas the etched Al-/Ga-polar surface was clean and smooth. The debris can be completely self-vanished on the N-polar Al0.4Ga0.6N surface after exposing in air for a few hours but still remained on the N-polar GaN surface even after over 1 month. The surface chemical analysis results suggested that the debris is the result of Cl-related byproduct generated during the etching process. Byproducts like Al(Ga)Clx and its derivatives are believed to cover on the N-polar surface after the inductively coupled plasma etching and increase the etched surface roughness significantly. The formation and disappearance of debris are attributed to the formation of Al(Ga)Clx⋅ 6H2O crystals when Al(Ga)Clx absorbs moisture in the air and its spontaneous decomposition on the N-polar surface, respectively. Adding O2/SF6 in the process helps remove Al(Ga)Clx byproducts but at the cost of roughened surface/reduced etch rate. With an additional cleaning process after etching, an uniform and smooth N-polar GaN surface with a low root-mean-square surface roughness of 0.5–0.6 nm has been successfully obtained at a reasonable etch rate (∼150 nm/min). The results can provide valuable guidance for the fabrication of high-performance N-polar GaN devices.https://www.frontiersin.org/articles/10.3389/fphy.2022.1042998/fullAl(Ga)NN-polarICP etchingsurface roughnessbyproducts |
| spellingShingle | Xiaoming Ge Xuebing Yin Qiaoyu Zeng Qi Feng Xiaohui Wang Quantong Li Zhitao Chen Chengguo Li Study of dry etched N-polar (Al)GaN surfaces obtained by inductively coupled plasma etching Frontiers in Physics Al(Ga)N N-polar ICP etching surface roughness byproducts |
| title | Study of dry etched N-polar (Al)GaN surfaces obtained by inductively coupled plasma etching |
| title_full | Study of dry etched N-polar (Al)GaN surfaces obtained by inductively coupled plasma etching |
| title_fullStr | Study of dry etched N-polar (Al)GaN surfaces obtained by inductively coupled plasma etching |
| title_full_unstemmed | Study of dry etched N-polar (Al)GaN surfaces obtained by inductively coupled plasma etching |
| title_short | Study of dry etched N-polar (Al)GaN surfaces obtained by inductively coupled plasma etching |
| title_sort | study of dry etched n polar al gan surfaces obtained by inductively coupled plasma etching |
| topic | Al(Ga)N N-polar ICP etching surface roughness byproducts |
| url | https://www.frontiersin.org/articles/10.3389/fphy.2022.1042998/full |
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