Cheng‐Ming Lin, Hung-Chih Chang, Yen‐Ting Chen, I-Hsieh Wong, H. Lan, S. Luo, Jing-Yi Lin, Y.-J. Tseng, Cheewee Liu, C. Hu, Fu-Liang Yang
{"title":"Interfacial layer-free ZrO2 on Ge with 0.39-nm EOT, κ∼43, ∼2×10−3 A/cm2 gate leakage, SS =85 mV/dec, Ion/Ioff =6×105, and high strain response","authors":"Cheng‐Ming Lin, Hung-Chih Chang, Yen‐Ting Chen, I-Hsieh Wong, H. Lan, S. Luo, Jing-Yi Lin, Y.-J. Tseng, Cheewee Liu, C. Hu, Fu-Liang Yang","doi":"10.1109/IEDM.2012.6479086","DOIUrl":null,"url":null,"abstract":"0.39-nm ultrathin EOT ZrO<sub>2</sub> having κ value as high as ~43 without an interfacial layer (IL) is demonstrated on Ge substrates. The EOT and gate leakage are much lower than the recent reported data [1]. In situ NH<sub>3</sub>/H<sub>2</sub> remote plasma treatment (RPT) after RTO-grown ultrathin (<;1nm) GeO<sub>2</sub>/Ge and prior to PEALD ZrO<sub>2</sub> leads to the formation of tetragonal phase ZrO<sub>2</sub> and the inhibition of GeO<sub>x</sub> IL regrowth. As the number of RPT cycles increases, it is observed that not only higher [N] but more GeO<sub>2</sub> component formed on Ge surface. GeO diffuses into ZrO<sub>2</sub> layer via the interface reaction (Ge+GeO<sub>2</sub> → 2GeO) and stabilize the tetragonal phase ZrO<sub>2</sub>. The gate dielectric has a leakage current ~10<sup>4</sup>X lower than other reported dielectrics in this EOT region. Ge (001) pMOSFET has low SS of 85 mV/dec and high I<sub>on</sub>/I<sub>off</sub> of ~6×10<sup>5</sup> at V<sub>d</sub>= -1V, while nMOSFET has SS of 90 mV/dec and I<sub>on</sub>/I<sub>off</sub> of ~1×10<sup>5</sup> at V<sub>d</sub>=1V. The peak electron mobility is determined by the remote phonon scattering stemming from the high-κ value. The biaxial tensile strain of ~0.04% applied on Ge (111) nMOSFET with an EOT=0.78nm produces a 4.8% drain current enhancement along the <;110> channel.","PeriodicalId":6376,"journal":{"name":"2012 International Electron Devices Meeting","volume":"1 1","pages":"23.2.1-23.1.4"},"PeriodicalIF":0.0000,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"21","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"2012 International Electron Devices Meeting","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/IEDM.2012.6479086","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 21
Abstract
0.39-nm ultrathin EOT ZrO2 having κ value as high as ~43 without an interfacial layer (IL) is demonstrated on Ge substrates. The EOT and gate leakage are much lower than the recent reported data [1]. In situ NH3/H2 remote plasma treatment (RPT) after RTO-grown ultrathin (<;1nm) GeO2/Ge and prior to PEALD ZrO2 leads to the formation of tetragonal phase ZrO2 and the inhibition of GeOx IL regrowth. As the number of RPT cycles increases, it is observed that not only higher [N] but more GeO2 component formed on Ge surface. GeO diffuses into ZrO2 layer via the interface reaction (Ge+GeO2 → 2GeO) and stabilize the tetragonal phase ZrO2. The gate dielectric has a leakage current ~104X lower than other reported dielectrics in this EOT region. Ge (001) pMOSFET has low SS of 85 mV/dec and high Ion/Ioff of ~6×105 at Vd= -1V, while nMOSFET has SS of 90 mV/dec and Ion/Ioff of ~1×105 at Vd=1V. The peak electron mobility is determined by the remote phonon scattering stemming from the high-κ value. The biaxial tensile strain of ~0.04% applied on Ge (111) nMOSFET with an EOT=0.78nm produces a 4.8% drain current enhancement along the <;110> channel.