Gaas-based phemt device and preparation method thereof

Abstract

The invention provides a GaAs-based pHEMT device and a preparation method therefor. The device comprises a GaAs substrate, a buffer layer, a first AlGaAs barrier layer, an InGaAs channel layer, a second AlGaAs barrier layer and a N<+>-GaAs layer. The channel layer and two barrier layers form two-dimensional electron gases respectively. A source electrode and a drain electrode are formed on the N<+>-GaAs layer. A recessed groove exposed from the second AlGaAs barrier layer is arranged between the source electrode and the drain electrode. A grid electrode is formed in the recessed groove. A nodal region with a high dielectric constant is arranged in a recessed groove between the grid electrode and the drain electrode. The nodal region with a high dielectric constant is embedded from the upper surface of the second AlGaAs barrier layer and extends into the interior. The distance of the source electrode to the grid electrode is equal to the distance of the drain electrode to the grid electrode. The transverse width of the recessed groove between the grid electrode and the drain electrode is more than the transverse width of the recessed groove between the grid electrode and the source electrode. The grid-drain breakdown voltage can be raised under a condition that device performances are not affected.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a GaAs-based pHEMT device and a preparation method thereof. Background technique [0002] GaAs (gallium arsenide) is the most important and widely used semiconductor material among III-V compound semiconductors. The electron mobility in GaAs is 6 times that of Si (silicon), and its electron peak drift speed is 2 times that of Si. Therefore, GaAs devices have the characteristics of high frequency, high speed, low power consumption, low noise, and monolithic integration. [0003] GaAs-based pHEMT device is a relatively mature three-terminal device among GaAs devices. It has the advantages of superior microwave and high-speed performance, relatively simple process, and stability. It is the focus of people's research. Output power and reliability are two important performance indicators of GaAs-based pHEMT devices. When the GaAs-based pHEMT device works in the s...

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Problems solved by technology

[0005] However, with the continuous advancement of semiconductor technology, improving the gate-drain breakdown voltage has gradually entered the bottleneck. For example, the working voltage and breakdown voltage of the 0.15μm process are generally difficult to exceed 8V and 20V, and the continuous improvement of RF front-end performance requirements requires The operating voltage of GaAs-based pHEMT devices continues to increase, which also means that GaAs-based pHEMT devices are required to have a higher gate-drain breakdown voltage, and the existing process can no longer meet this requirement

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