Rui Zhang, Po-Chin Huang, Ju-Chin Lin, M. Takenaka, S. Takagi
{"title":"Physical mechanism determining Ge p- and n-MOSFETs mobility in high Ns region and mobility improvement by atomically flat GeOx/Ge interfaces","authors":"Rui Zhang, Po-Chin Huang, Ju-Chin Lin, M. Takenaka, S. Takagi","doi":"10.1109/IEDM.2012.6479051","DOIUrl":null,"url":null,"abstract":"Hall measurements have been carried out for the Ge p-and n-MOSFETs with different substrate orientations and GeO<sub>x</sub>/Ge interface qualities. It is found that the significant reduction of effective mobility in high surface carrier concentration (N<sub>s</sub>) or high normal field in Ge MOSFETs is attributed partly to the N<sub>s</sub> loss due to large amounts of interface states inside the valence and conduction bands of Ge. The GeO<sub>x</sub>/Ge interface roughness is another reason limiting the high N<sub>s</sub> mobility. It has been revealed that room temperature plasma post oxidation can realize Al<sub>2</sub>O<sub>3</sub>/GeO<sub>x</sub>/Ge gate stacks with atomically-flat GeO<sub>x</sub>/Ge interfaces. Ge MOSFETs with these interfaces have provided record high effective hole and electron mobility, which overcome the Si universal mobility in both low and high N<sub>s</sub> regions.","PeriodicalId":6376,"journal":{"name":"2012 International Electron Devices Meeting","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"22","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"2012 International Electron Devices Meeting","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/IEDM.2012.6479051","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 22
Abstract
Hall measurements have been carried out for the Ge p-and n-MOSFETs with different substrate orientations and GeOx/Ge interface qualities. It is found that the significant reduction of effective mobility in high surface carrier concentration (Ns) or high normal field in Ge MOSFETs is attributed partly to the Ns loss due to large amounts of interface states inside the valence and conduction bands of Ge. The GeOx/Ge interface roughness is another reason limiting the high Ns mobility. It has been revealed that room temperature plasma post oxidation can realize Al2O3/GeOx/Ge gate stacks with atomically-flat GeOx/Ge interfaces. Ge MOSFETs with these interfaces have provided record high effective hole and electron mobility, which overcome the Si universal mobility in both low and high Ns regions.