CN201927612U - GaN HEMT - Google Patents

Abstract

The utility model relates to a GaN (gallium nitride) HEMT (high electron mobility transistor). The GaN HEMT comprises a substrate, wherein a buffer layer, an interposed layer, an insulating layer, a barrier layer and a cap layer sequentially grow on the substrate in an extension manner; the grid electrode, the source electrode and the drain electrode of the transistor are positioned on the cap layer; the buffer layer is GaN with a thickness of 2.5Mum; the interposed layer is A10.04Ga0.96N with a thickness of 4nm; the insulating layer is A10.31Ga0.69N with a thickness of 3nm; the barrier layer doped with silicon is A10.31Ga0.69N with a thickness of 20nm and has the doping concentration of 3.5*10<18>cm<-3>; and the cap layer is A10.31Ga0.69N with a thickness of 2nm. In the utility model, the epilayer structure of the GaN HEMT is changed, and the related parameters of the epilayer structure is optimized, so that the transconductance change of the GaN HEMT in operation is smaller when the grid voltage is within a certain working range, and the GaN HEMT has higher degree of linearity.

Description

A kind of GaN high electron mobility transistor

Technical field

The utility model belongs to microelectronics technology, particularly a kind of GaN high electron mobility transistor.

Background technology

Along with developing rapidly of radio communication, more and more higher to the performance requirement of microwave amplifier, promptly require high frequency, low noise, high power, high efficiency and high linearity.In traditional communication system, under the low frequency, silicon device occupies leading and ascendancy in occupation of the staple market at microwave and millimeter wave frequency range GaAs device.In recent years along with the development of technology, the silicon device millimeter wave frequency band of also can having worked, but the low power density of silicon device can't satisfy the requirement of high-power component.The GaAs device of the microwave and millimeter wave frequency range of can having worked, on high power performance also near its limiting value.In order to obtain higher power density, a kind of broad-band gap, high-breakdown-voltage and good hot property semi-conducting material gallium nitride are subjected to people's very big concern and research.

Compare with GaAs material with silicon, gallium nitride material has better electric property, makes Al _XGa _1-XN/GaNHEMT (High Electron Mobility Transistor) become have high frequency, high power density, high temperature, high linearity and low-noise device, also make it become the main replacer of amplifier, modulator and other Primary Component in the following high level communication network.All have a wide range of applications in military-civil fields such as cellular base station, automobile, aviation and phased array radars.In the real work,, require device to have high linearity in order to obtain high-quality audio frequency and video.Although Al _XGa _1-XN/GaN HEMT has remarkable advantages with respect to silicon and GaAs device on the power and the linearity, but passes through the improvement and the Parameter Optimization of device epitaxial layers structure, can further improve its linearity.

The utility model content

The purpose of this utility model just provides the GaN high electron mobility transistor of a kind of epitaxial layer structure and parameter optimization.

The utility model comprises substrate, in the substrate successively epitaxial growth resilient coating, insert layer, separator, barrier layer and cap layer are arranged, transistorized grid, source electrode and drain electrode are positioned on the cap layer.

The material of described substrate is sapphire, silicon or carborundum;

Described resilient coating is that thickness is the GaN of 2.5um;

Described insert layer is that thickness is the Al of 4nm _0.04Ga _0.96N;

Described separator is that thickness is the Al of 3nm _0.31Ga _0.69N;

Described barrier layer is the Al of doped silicon element _0.31Ga _0.69N, doping content is 3.5 * 10 ¹⁸Cm ^-3, thickness is 20nm:

Described cap layer is the cap layer Al of 2nm for thickness _0.31Ga _0.69N;

Described gate metal is that nickel or gold, source metal are that titanium or aluminium or nickel or gold, drain metal are titanium or aluminium or nickel or gold.

The routine techniques means are adopted in the epitaxial growth of each layer in the utility model method, and inventive point of the present utility model is the epitaxial layer structure of device and the relevant parameter of each epitaxial loayer.

The utility model is optimized the relevant parameter of epitaxial layer structure simultaneously by changing the epitaxial layer structure of device, makes that device mutual conductance variation of grid voltage device in the certain limit working range when work is very little, also is that device has higher linearity.

Description of drawings

Fig. 1 is a structural representation of the present utility model.

Embodiment

A kind of GaN high electron mobility transistor comprises sapphire substrates 1, on the sapphire substrates 1 successively epitaxial growth thickness is arranged is that GaN resilient coating 2, the thickness of 2.5um is the Al of 4nm _0.04Ga _0.96N insert layer 3, thickness are the Al of 3nm _0.31Ga _0.69N separator 4, thickness are the Al of 20nm _0.31Ga _0.69N barrier layer 5 and thickness are the Al of 2nm _0.31Ga _0.69N cap layer 6, barrier layer 5 doped silicon elements wherein, doping content is 3.5 * 10 ¹⁸Cm ^-3Transistorized grid 8, source electrode 7 and draining 9 is positioned on the cap layer 6, and gate metal is that nickel or gold, source metal are that titanium or aluminium or nickel or gold, drain metal are titanium or aluminium or nickel or gold.

Practice shows, the mutual conductance of grid voltage device in the certain limit working range changes very for a short time during the GaN high electron mobility transistor work of this kind structure and parameter, and device has higher linearity.

Claims (1)

1. a GaN high electron mobility transistor comprises substrate, it is characterized in that: in the substrate successively epitaxial growth resilient coating, insert layer, separator, barrier layer and cap layer are arranged, transistorized grid, source electrode and drain electrode are positioned on the cap layer;

Described substrate is sapphire, silicon or carborundum;

The thickness of described resilient coating is 2.5um;

The thickness of described insert layer is 4nm;

The thickness of described separator is 3nm;

The thickness of described barrier layer is 20nm;

The thickness of described cap layer is 2nm;

Described gate metal is that nickel or gold, source metal are that titanium or aluminium or nickel or gold, drain metal are titanium or aluminium or nickel or gold.