Characterization and Analysis of Oxide Interface Charge for FinFETs

• Main Authors: Ju-LiangLai, 賴如諒
• Other Authors: Meng-Hsueh Chiang
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/rbn262

碩士 === 國立成功大學 === 奈米積體電路工程碩士學位學程 === 105 === With the progress of semiconductor process and device scaling, there is serious short channel effect when proceeding the scaling of transistors. Increasing the gate controllability by multi gate structure is one of methods to improve the short channel effect. FinFETs has been widely applied and used for manufacturing CMOS devices in the semiconductor industrial field. However, while manufacturing FinFETs on the bulk silicon wafer, it is necessary to control the fin height by high intensity plasma etching and deposition of insulating oxide layer. The interface oxide charge is thus produced at the interfacial region between silicon and oxide in this process, which cause degrading of device performance. In this thesis. We calibrate successfully the electrical performance of device, such as capacitance-voltage (C-V) and current-voltage (I-V) by measurements of devices and three dimensional mathematical simulation software. From the C-V curve, equivalent oxide thickness (EOT) can be calculated and then the extracted EOT could be substituted into device simulation. From the I-V curve, the charge density of interface oxide layer can be obtained. In order to further investigate the influence of interface oxide charge on devices, we consider the impact of different parameters on FinFETs. The simulated results show that wide fin width, heavy substrate doping, shallow junction depth and proper punch through stopper layer depth tend to effectively reduce the leakage current when high interface oxide charge density and thus degraded subthreshold swing (SS) and drain-induced barrier lowering (DIBL) have occurred. By using oxygen ion implantation under the channel and further oxidation into oxide layer, it is found to be the most effective method to inhibit leakage current.