Ga2O3 material-based cap layer composite double-gate P-type metal-oxide-semiconductor field-effect transistor (PMOSFET) and preparation method thereof

Abstract

The invention relates to a Ga2O3 material-based cap layer composite double-gate P-type metal-oxide-semiconductor field-effect transistor (PMOSFET) and a preparation method thereof. The method comprises the steps of selecting an N-type semi-insulation substrate, growing an N-type Beta-Ga2O3 layer by molecular beam epitaxy, and forming a table surface by dry etching; forming a source region and a drain region at two side positions of the table surface by an ion injection process; forming a source electrode and a drain electrode at two side positions near to the source region and the drain region; forming a first gate dielectric layer and a second gate dielectric layer at inclined surface positions of the other two sides, near to a source region side, of the table surface by a magnetron sputtering process; forming cap layers on surfaces of the first gate dielectric layer and the second gate dielectric layer; and forming gate electrodes on surfaces of the cap layers. Two materials with different dielectric constants are used as composite gate oxide layers to transmit holes and block electrons so as to improve the transmission efficiency; and the relatively thin cap layers are used, a dipole layer is formed at a gate oxide layer / Ga2O3 interface by a high-temperature process, thus, the adjustment of a band edge function is achieved, and the device reliability is improved.

Description

technical field [0001] The invention belongs to the technical field of integrated circuits, in particular to a Ga-based 2 o 3 Cap layer compound double-gate PMOSFET of material and its preparation method. Background technique [0002] MOS devices, that is, metal-oxide-semiconductor field effect transistors, have been completely different in structure and performance from the previous bipolar integrated circuits since their inception. MOS integrated circuits have high input impedance, strong anti-interference ability, low power consumption, The advantages of high integration and so on have become the mainstream of the VLSI era. MOS devices are divided into NMOS, PMOS, and CMOS according to different substrates and different conductive channels. Among them, MOS devices that use N-type substrates to form P-type channels are PMOS. [0003] PMOS is turned on after Vgs is less than a fixed value. The carrier that the current transmission of the device depends on is a hole, so i...

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Problems solved by technology

[0005] The current third-generation wide-bandgap semiconductor material Ga 2 o 3 As a new research direction of semiconductor integrated circuit power devices and optoelectronic devices, MOSFETs of materials, but due to β-Ga 2 o 3 When the substrate is applied to high-speed devices, there are disadvantages such as insufficient hole transport rate and low thermal conductivity compared with other wide-bandgap materials. In addition, the metal gate / high-k gate dielectric structure is applied to Ga 2 o 3 The serious Fermi pinning effect appears on the substrate, which greatly affects the Ga 2 o 3 Device Performance of PMOSFET

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