Influence of Pocket Implant Angles on Digital and Analog Performances of Nano-MOSFETs
| Autor: | Wen-Cheng Lin, 林文政 |
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| Rok vydání: | 2006 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 94 Pocket or halo implant is commonly used in the process of high performance logic CMOS technology in order to control the short channel effect (SCE) of MOSFETs. But, it is believed that the implant also degrades the MOSFETs’ analog performance such as early voltage (VA) and output resistance (Rout). However, our previous research revealed that that heavy pocket implant can improve the Rout and VA of very short channel nMOSFETs because the implant has generated laterally flat doping concentration along the channel. Accordingly, it is necessary to thoughtfully investigate what analog and digital characteristics the MOSFETs will generate in respect to the different lateral doping profiles constructed by different pocket implants. To implement above motivation, ISE TCAD simulation in cooperation with UMC 90 nm node experimental data were performed in this research. To be specific, three channel doping profiles named M, F and A types were constructed by using small (15°), medium (30°) and large (40°) pocket implant angles, respectively. Differences of using species of boron and BF2 were also included in this research after analyzing the simulation results, it is found that A type can suppress off-state current but can cause serious reverse short channel effect (RSCE). Therefore, A type is recommended suitable for low standby power (LSTP) applications. M type shows excellent analog performance in comparison with other two types, especially for M type with boron species, which is recommended most suitable for analog circuits. As for the F type, the simulation shows it applicable to digital devices. Finally, the probable best choice for mixed-signal applications is using boron pocket implant though choosing appropriate pocket implant angles between small and medium. Thus, the device may not need trade-off at short channel region when facing both analog and digital requirements. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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