Composite channel MHEMT (Metamorphic High Electron Mobility Transistor) microwave oscillator and preparation method thereof

Abstract

The invention discloses a composite channel MHEMT (Metamorphic High Electron Mobility Transistor) microwave oscillator and a preparation method thereof. The device is of a composite channel structure; mesa isolation of combined ion injection and wet corrosion is adopted; a source-drain metallic system of Ni / AuGe / Ni / Au forms ohmic contact; a T-shaped gate is manufactured by using a three-layer resist technology of two self-alignment processes of an electronic exposure beam and one development process; two different kinds of corrosion solution are used for corroding to form a gate groove; a vaporized Pt / Ti / Pt / Au metallic system forms schottky contact in the gate groove; buried Pt is formed through annealing treatment; a silicon nitride passivation layer is formed; thus the preparation of the device is finished. The oscillator and the method have the advantages of simple process, high reliability of the device and convenience in repetition. Superior direct current performance and alternating current performance are obtained by using the prepared device with gate length of 80 nanometers, the maximum output saturation current reaches 920 mA / mm, and the extrinsic transconductance reaches 1,100 mS / mm. The characteristic frequency of the device reaches 246GHz, and the maximum oscillation frequency is 301GHz.

Description

technical field [0001] The invention belongs to the field of microwave communication devices, in particular to a composite channel MHEMT (variable composition high electron mobility transistor) microwave oscillator and a preparation method thereof. Background technique [0002] Microwave oscillators are very important components in microwave receiving systems. At present, there are two types of commonly used microwave oscillations, namely electric vacuum devices and solid state devices. Electric vacuum devices mainly include microwave electric vacuum triodes, reflection klystrons, magnetrons and return wave tubes; solid devices include crystal triodes, body effect diodes (also known as Gunn diodes) and avalanche diodes. Due to the relatively harsh requirements on the manufacturing environment and process of the electric vacuum device, its manufacturing cost is high, and it cannot be popularized and promoted, so it is rarely used in microwave mobile communication equipment. ...

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Problems solved by technology

However, the channel two-dimensional electron gas concentration and electron mobility of the traditional GaAs substrate HEMT are affected by the material structure and cannot make the conductive channel electron mobility and two-dimensional electron gas concentration very large, making the device work The small dynamic range limits the development of GaAs substrate HEMT devices in microwave oscillation circuits and microwave communications

Although the high electron mobility transistor channel of the InP substrate has a high two-dimensional electron gas concentration and electron mobility in the channel, the manufacturing cost of the InP substrate is high and the material is brittle, which is not conducive to popularization.

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