150–200 V Split-Gate Trench Power MOSFETs with Multiple Epitaxial Layers

A rating voltage of 150 and 200 V split-gate trench (SGT) power metal-oxide- semiconductor field-effect transistor (Power MOSFET) with different epitaxial layers was proposed and studied. In order to reduce the specific on-resistance (Ron,sp) of a 150 and 200 V SGT power MOSFET, we used a multiple epitaxies (EPIs) structure to design it and compared other single-EPI and double-EPIs devices based on the same fabrication process. We found that the bottom epitaxial (EPI) layer of a double-EPIs structure can be designed to support the breakdown voltage, and the top one can be adjusted to reduce the Ron,sp. Therefore, the double-EPIs device has more flexibility to achieve a lower Ron,sp than the single-EPI one. When the required voltage is over 100 V, the on-state resistance (Ron) of double-EPIs device is no longer satisfying our expectations. A triple-EPIs structure was designed and studied, to reduce its Ron, without sacrificing the breakdown voltage. We used an Integrated System Engineering-Technology Computer-Aided Design (ISE-TCAD) simulator to investigate and study the 150 V SGT power MOSFETs with different EPI structures, by modulating the thickness and resistivity of each EPI layer. The simulated Ron,sp of a 150 V triple-EPIs device is only 62% and 18.3% of that for the double-EPIs and single-EPI structure, respectively

Raised Source/Drain (RSD) and Vertical Lightly Doped Drain (LDD) Poly-Si Thin-Film Transistor

The raised source/drain (RSD) structure is one of thin film transistor designs that is often used to improve device characteristics. Many studies have mentioned that the high impact ionization rate occurring at a drain side can be reduced, owing to a raised source/drain area that can disperse the drain electric field. In this study, we will discuss how the electric field at the drain side of an RSD device is reduced by a vertical lightly doped drain (LDD) scheme rather than a RSD structure. We used different raised source/drain forms to simulate the drain side electric field for each device, as well as their output characteristics, using Integrated Systems Engineering (ISE-TCAD) simulators. Different source and drain thicknesses and doping profiles were applied to verify the RSD mechanism. We found that the electric fields of a traditional device and uniform doping RSD structures are almost the same (~2.9 × 105 V/cm). The maximum drain electric field could be reduced to ~2 × 105 V/cm if a vertical lightly doped drain RSD scheme was adopted. A pure raised source/drain structure did not benefit the device characteristics if a vertical lightly doped drain design was not included in the raised source/drain areas

Thin-Film Transistors

Thin film transistors (TFTs) are key components used in a variety of fields such as solar cell, active-matrix liquid crystal displays (AM-LCDs), pixel switches, peripheral driver circuit and flexible electronics [...

The influence of sports lottery purchase on sports participation behavior

The purpose of this research is to understand the influence of sports lottery consumption motivation and sport spectators on sports participation behavior. In thepresent study, a total of 500 questionnaires were issued. Out of those, 479 valid questionnaires were returned. Self-compiled consumption motivation scale, sports spectators scale and sports participation behavior scale were used as research tools, with sports lottery ticket purchasers as the research object of the current study.The effective return rate is up to 95.8%. Followed by data collection, statistical analysis was done using various statistical tests which include, descriptive statistics, independent sample t test, single factor variance analysis and snow-fee method post-comparison, Pearson product difference correlation, multiple stepwise regression analysis and logistic regression. Conclusion: The overall consumption motivation of sports lotteryconsumers present a medium-level cognition situation. The sports spectators scale present a medium-to-low level situation, and the overall sports participation behavior-goal identity present a medium-to-high level cognition situation. Gender has a significant role with respect to entertainment factors and sports spectators in the consumption motivation factor dimension. Age has a significant role with respect to the public welfare factor in the consumption motivation factor dimension; education degree is in the consumption motivation factor dimension of economic factor, public welfare factor and sports spectators and sports participation behaviors-goal identification were found to be significantly different. Marriage had a significant difference in consumption motivation factor in terms of entertainment factor, public welfare factor and sports spectators and sports participation behaviors-goal identification; occupation is in consumption motivation factors economic factor, public welfare factors have reached a significant difference; monthly income has a significant difference in consumption motivation and sports spectators. Significant correlation was found between consumption motivation and sports appreciation. Consumption motivation had a positive effect on sports participation behavior-goal identification shows entertainment factor and public welfare factor; sports spectators show a positive influence on sports participation behavior-goal identification. Sports spectators had shown a significant relationship between sports participation behavior and actual participation

Raised Source/Drain (RSD) and Vertical Lightly Doped Drain (LDD) Poly-Si Thin-Film Transistor

The raised source/drain (RSD) structure is one of thin film transistor designs that is often used to improve device characteristics. Many studies have mentioned that the high impact ionization rate occurring at a drain side can be reduced, owing to a raised source/drain area that can disperse the drain electric field. In this study, we will discuss how the electric field at the drain side of an RSD device is reduced by a vertical lightly doped drain (LDD) scheme rather than a RSD structure. We used different raised source/drain forms to simulate the drain side electric field for each device, as well as their output characteristics, using Integrated Systems Engineering (ISE-TCAD) simulators. Different source and drain thicknesses and doping profiles were applied to verify the RSD mechanism. We found that the electric fields of a traditional device and uniform doping RSD structures are almost the same (~2.9 × 105 V/cm). The maximum drain electric field could be reduced to ~2 × 105 V/cm if a vertical lightly doped drain RSD scheme was adopted. A pure raised source/drain structure did not benefit the device characteristics if a vertical lightly doped drain design was not included in the raised source/drain areas

Double-Gate Two-Step Source/Drain Poly-Si Thin-Film Transistor

A current improved and electric field reduced double-gate (DG) polycrystalline silicon thin-film transistor with two-step source/drain (DGTSD-TFT) design is proposed and demonstrated in this study. The two-step source/drain (TSD) design, which consists of a raised source/drain (RSD) area together with a partial gate overlapped lightly doped drain (P-GOLDD) structure, can lower the device drain electric field (DEF) to reveal a better device performance. Comparisons have been made with respect to a traditional single top gate (STG) device. The operation current of the proposed DGTSD-TFT is almost twice as large as that of the STG structure. The OFF-state leakage current and kink effect, as well as the ON/OFF current ratio for this double-gate and two-step source/drain structure, are also improved simultaneously because of a reduced DEF. A hot carrier stress test reveals that that two-step source/drain structure can achieve more stable device characteristics than the traditional device

Normally-Off p-GaN Gated AlGaN/GaN MIS-HEMTs with ALD-Grown Al2O3/AlN Composite Gate Insulator

A metal–insulator–semiconductor p-type GaN gate high-electron-mobility transistor (MIS-HEMT) with an Al2O3/AlN gate insulator layer deposited through atomic layer deposition was investigated. A favorable interface was observed between the selected insulator, atomic layer deposition–grown AlN, and GaN. A conventional p-type enhancement-mode GaN device without an Al2O3/AlN layer, known as a Schottky gate (SG) p-GaN HEMT, was also fabricated for comparison. Because of the presence of the Al2O3/AlN layer, the gate leakage and threshold voltage of the MIS-HEMT improved more than those of the SG-HEMT did. Additionally, a high turn-on voltage was obtained. The MIS-HEMT was shown to be reliable with a long lifetime. Hence, growing a high-quality Al2O3/AlN layer in an HEMT can help realize a high-performance enhancement-mode transistor with high stability, a large gate swing region, and high reliability