{"title":"The use of ZnS as a sacrificial layer in the construction of PECVD SiN/sub x/ self-supporting structures","authors":"K. Winchester, S.M.R. Spaargaren, J. Dell","doi":"10.1109/COMMAD.1998.791698","DOIUrl":null,"url":null,"abstract":"The construction of freestanding microstructures requires the use of a sacrificial etch layer. Whilst SiO/sub 2/ is commonly employed as a sacrificial layer for LPCVD silicon nitride structures, we have found that it is incompatible with thin self-supporting membranes of PECVD silicon nitride. Specifically, when fabricating such self-supporting membranes the selectivity of the membrane to the SiO/sub 2/ etch is too low. This problem causes the membrane structure to be etched significantly during the long etch times required to release a device from the sacrificial layer. It is shown that by using ZnS as a sacrificial layer, thin self-supporting membrane microstructures formed from PECVD silicon nitride can be accomplished. This process allows integration of MEMs structures with semiconductors that are incompatible with high temperature processing.","PeriodicalId":300064,"journal":{"name":"1998 Conference on Optoelectronic and Microelectronic Materials and Devices. Proceedings (Cat. No.98EX140)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"1998-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"9","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"1998 Conference on Optoelectronic and Microelectronic Materials and Devices. Proceedings (Cat. No.98EX140)","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/COMMAD.1998.791698","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 9
Abstract
The construction of freestanding microstructures requires the use of a sacrificial etch layer. Whilst SiO/sub 2/ is commonly employed as a sacrificial layer for LPCVD silicon nitride structures, we have found that it is incompatible with thin self-supporting membranes of PECVD silicon nitride. Specifically, when fabricating such self-supporting membranes the selectivity of the membrane to the SiO/sub 2/ etch is too low. This problem causes the membrane structure to be etched significantly during the long etch times required to release a device from the sacrificial layer. It is shown that by using ZnS as a sacrificial layer, thin self-supporting membrane microstructures formed from PECVD silicon nitride can be accomplished. This process allows integration of MEMs structures with semiconductors that are incompatible with high temperature processing.