High-performance GaAs metal-oxide-semiconductor capacitor by using NbAlON as high-k gate dielectric

Abstract

A GaAs metal-oxide-semiconductor (MOS) capacitor using NbAlON as a gate dielectric with different Nb contents is fabricated. Experimental results show that the k value and crystallization temperature of the AlON dielectric can be improved by Nb incorporation, together with reduction in negative oxide charges. However, the interface quality and gate leakage become poorer as the Nb content increases, as confirmed by TEM and X-ray photoelectron spectroscopy results. Therefore, through comprehensively considering the advantages and disadvantages, the sample with a Nb/(AlþNb) atomic ratio of 62.5% exhibits the best characteristics: high k value (23.3), low interface-state density (2.7 Â 10 12 cm À2 /eV), small hysteresis (55 mV), small frequency dispersion, and low gate leakage current (2.66 Â 10 À5 A/cm 2 at V fb þ 1 V). By comparing with reported GaAs MOS devices with different high-k gate dielectrics, it can be suggested that NbAlON is a promising gate dielectric material to achieve excellent electrical performance for GaAs MOS devices.

Modulating the Interface Chemistry and Electrical Properties of Sputtering-Driven HfYO/GaAs Gate Stacks by ALD Pulse Cycles and Thermal Treatment

“…As a result, III–V compound semiconductors with high mobility are being investigated as one of the promising technology boosters to enhance MOSFET performance. Among III–V semiconductors, more attention has been paid to the investigation of GaAs-based channel materials for continuing the scaling of MOSFETs devices due to its larger band gap, higher breakdown field, and higher carrier mobility than other candidates. − However, due to the existence of native oxides, GaAs are likely to form extrinsic defects attributed to the high interface state density ( D it ). The high D it associated with the dielectric/III–V interface causes Fermi-level pinning at the midgap and large capacitance frequency dispersion, which leads to the degraded electrical performance. , Additionally, the oxygen atoms in high- k gate dielectrics can diffuse easily into the substrate, leading to the formation of a low- k interfacial layer and increased oxygen vacancies between high- k and the GaAs substrate.…”

“…Among III–V semiconductors, more attention has been paid to the investigation of GaAs-based channel materials for continuing the scaling of MOSFETs devices due to its larger band gap, higher breakdown field, and higher carrier mobility than other candidates. 11−13 However, due to the existence of native oxides, GaAs are likely to form extrinsic defects attributed to the high interface state density ( D it ). The high D it associated with the dielectric/III–V interface causes Fermi-level pinning at the midgap and large capacitance frequency dispersion, which leads to the degraded electrical performance.…”

Single β-Ga2O3 nanowire back-gate field-effect transistor

“…The subthreshold swing (SS) and maximum transconductance (g m ) are 250 mV dec −1 and 0.19 µS, respectively. The use of high-k value materials, such as Al 2 O 3 and HfO 2 to replace SiO 2 may potentially increase the g m and SS [32][33][34][35][36]. In fact, the clockwise hysteresis in figure 3…”

Improved Electrical Properties and Reliability of GaAs Metal-Oxide-Semiconductor Capacitor by Using LaAlON Passivation Layer

“…However, it is well known that hygroscopicity is a crucial problem of La‐based materials, negatively affecting the device performance . So, it is expected that replacing the expensive La by Nb in LaAlO 3 could result in higher moisture resistance and much higher k value ( k > 40 for Nb 2 O 5 ) for the gate dielectric to enhance the device performance at a lower cost . Furthermore, interface states caused severer impact on the performance of MOS device with n‐type GaAs substrate than that of its p‐type counterpart, leading to much larger frequency dispersion, and so improving the properties of n‐GaAs MOS device has become a bigger challenge to achieve GaAs CMOS applications.…”