The V th is defined as the gate voltage at I d = 10−9 A. The temperature coefficients of V th are −1.34 and −5.01 mV/°C for GAA and planar XAV-939 clinical trial JL TFTs, respectively. According to , the variation of in n-type JL devices can be expressed as follows : (4) Figure 4 Impact of temperature dependence on the (a) V th and (b) on-state currents. For JL GAA TFTs (L g = 1 μm, 60 nm) and JL planar TFTs (L g = 1 μm). The Vth and Ion for JL GAA TFTs are less sensitive to temperature than JL planar TFTs. where V fb is the flat-band voltage, C ox is the gate oxide capacitance per unit length, A is the device cross-sectional area and P is the gate perimeter. The first term in the right side of Equation
4 is depended on the flat-band voltage variation with temperature. For N D = 1 × 1019 cm−3, the value of is approach to −0.49 mV/°C as the devices in , which has a P+ polycrystalline silicon gate and the same doping concentration. The second term
represents the Selleckchem Volasertib effect of incomplete ionization. The doped impurities are almost completely ionized at those temperatures higher than room temperature. Thus, the doping concentration variation with the temperature has a slight dependence on temperature. The third term, depending on the electron effective mass, also has a smaller dependence on T than the other terms. The theoretical value of is about −0.49 mV/°C; although the of −1.34 mV/°C in JL GAA TFTs is larger than theoretical value, but is comparable with current SOI-based JNT ( approximately −1.63 mV/°C)  due to the use of the multi-gate structure and formation of
a crystal-like nanosheet GSK621 price channel with fewer traps by oxidation process. Therefore, JL TFTs with the GAA structure and ultra-thin channel shows an excellent immunity to the temperature dependence on V th and competes with SOI-based JNT. Figure 4b presents the measured on-current (I on) as a function of temperature. The I on is defined as the drain current at V g = 3 V for JL planar TFTs and at V g = 6 V for JL GAA TFTs. The JL GAA TFTs show a slightly better I on variation with Depsipeptide temperature than the planar ones, possibly owing to a smaller in JL GAA TFTs. Conclusion This work has presented a high-temperature operation of JL TFTs. The high temperature dependence of JL GAA and planar TFTs is also studied. The variation of parameters such as V th, I on, SS, and I off are analyzed as well. The variation of the SS with temperature for JL GAA TFTs is close to the ideal value (0.2 mV/dec/K) owing to the ability of the oxidation process to form a nanosheet channel and crystal-like channel. Additionally, I off is negligibly small for JL GAA TFTs, owing to quantum confinement effect; its E g of 1.35 eV is also extracted. The JL GAA TFTs have a smaller than that of JL planar TFTs owing to the GAA structure and ultra-thin channel.