CN205211760U

CN205211760U - Non - alloy ohmic contact's gaN HEMT device

Info

Publication number: CN205211760U
Application number: CN201521049123.0U
Authority: CN
Inventors: 黎明; 陈汝钦
Original assignee: Chengdu Hiwafer Technology Co Ltd
Current assignee: Chengdu Hiwafer Technology Co Ltd
Priority date: 2015-12-16
Filing date: 2015-12-16
Publication date: 2016-05-04
Anticipated expiration: 2025-12-16

Abstract

The utility model provides a non - alloy ohmic contact's gaN HEMT device, it includes by the lower supreme substrate that stacks gradually, doping gaN buffer layer, non - doping gaN channel layer and non - doping alGaN barrier layer, form two dimensional electron gas between non - doping gaN channel layer and the non - doping alGaN barrier layer, the slot has been offered in the source region and the region that drains of non - doping alGaN barrier layer, the slot gos deep into inside the doping gaN buffer layer from the surface of non - doping alGaN barrier layer, it has n type inGaN epitaxial layer to grow in the slot, be formed with the source electrode on the n of source region type inGaN epitaxial layer, be formed with the drain electrode on the n type inGaN epitaxial layer in drain electrode region. In this way, the utility model discloses can avoid high temperature annealing to bring lattice damage to the gaN device.

Description

The GaN HEMT device of non-alloyed ohmic contact

Technical field

The utility model relates to technical field of semiconductor device, particularly relates to a kind of GaNHEMT device of non-alloyed ohmic contact.

Background technology

Because wide bandgap semiconductor gallium nitride (GaN) material has the Johnson figure of merit (5THzV) of superelevation, when its device channel size reaches 10nm magnitude, puncture voltage still can remain on about 10V, cause gradually and extensively pay attention to both at home and abroad, require high conversion efficiency and accurate threshold control, broadband, great dynamic range the digital and electronic field of circuit (as ultra broadband ADC, DAC) there is wide and special application prospect, be particularly useful for supporting national defense communication, airborne and space system.At present, the processing yardstick of GaNHEMT logical device has entered the category of GaN nano-electron, f _treach 190GHz, just march towards 300GHz to 500GHz, become the developing new opportunity of third generation semiconductor, in ultrahigh speed field, there is boundless development potentiality.

But to be limited to GaN cap work function higher due to conventional GaN device, conventional doping way such as cannot to realize at the defect, cannot form good ohmic contact at present, cause device power to fail serious.In order to realize good ohmic contact, the common way of industry adopts the mode of high annealing to realize ohmic contact, but, the temperature of high annealing reaches 850-900 degree, this close to the growth temperature of GaN (920 degree), so can bring lattice damage to GaN, can increase the weight of electric leakage and the current collapse of GaN device, and cause the integrity problem of GaN device, be the Main Bottleneck hindering the raising of GaN device performance and practical application.

Utility model content

The technical problem that the utility model mainly solves is to provide a kind of GaNHEMT device of non-alloyed ohmic contact, and high annealing can be avoided to bring lattice damage to GaN device.

For solving the problems of the technologies described above, the technical scheme that the utility model adopts is: the GaNHEMT device providing a kind of non-alloyed ohmic contact, comprise the substrate stacked gradually from the bottom to top, Doped GaN resilient coating, undoped GaN channel layer and undoped AlGaN potential barrier, two-dimensional electron gas is formed between described undoped GaN channel layer and described undoped AlGaN potential barrier, source region and the drain region of described undoped AlGaN potential barrier offer groove, described groove gos deep into described Doped GaN resilient coating from the surface of described undoped AlGaN potential barrier inner, in described groove, growth has N-shaped InGaN epitaxial loayer, the N-shaped InGaN epitaxial loayer of described source region is formed with source electrode, the N-shaped InGaN epitaxial loayer of described drain region is formed with drain electrode.

Preferably, described source electrode and described drain electrode are single or multiple lift metal.

Preferably, described multiple layer metal is Ti/Al/Ni/Au.

Preferably, described substrate is Si substrate, SiC substrate or Sapphire Substrate.

Preferably, doped with Si in described N-shaped InGaN epitaxial loayer, doping content is 1 × 10 ¹⁹-5 × 10 ¹⁹.

Preferably, in described N-shaped InGaN epitaxial loayer, the content of In rises to 80% along with described N-shaped InGaN epitaxy layer thickness increases from 0%.

Be different from the situation of prior art, the beneficial effects of the utility model are: because the energy gap of N-shaped InGaN epitaxial loayer can lower than 1eV, by forming source electrode and drain electrode on N-shaped InGaN epitaxial loayer, good non-alloyed ohmic contact can be formed, without the need to carrying out high annealing, thus high annealing can be avoided to bring lattice damage to GaN device, the Performance And Reliability of device can be improved, effective raising raceway groove two-dimensional electron gas, reduce ohmic contact layer surface and edge roughness, be conducive to the carrying out of subsequent technique.

Accompanying drawing explanation

Fig. 1 is the structural representation of the GaNHEMT device of the utility model embodiment non-alloyed ohmic contact.

Embodiment

Below in conjunction with the accompanying drawing in the utility model embodiment, be clearly and completely described the technical scheme in the utility model embodiment, obviously, described embodiment is only a part of embodiment of the present utility model, instead of whole embodiments.Based on the embodiment in the utility model, those of ordinary skill in the art are not making the every other embodiment obtained under creative work prerequisite, all belong to the scope of the utility model protection.

See Fig. 1, it is the structural representation of the GaNHEMT device of the utility model embodiment non-alloyed ohmic contact.The GaNHEMT device of the non-alloyed ohmic contact of the present embodiment comprises the substrate 1 stacked gradually from the bottom to top, Doped GaN resilient coating 2, undoped GaN channel layer 3 and undoped AlGaN potential barrier 4, two-dimensional electron gas 31 is formed between undoped GaN channel layer 3 and undoped AlGaN potential barrier 4, the source region of undoped AlGaN potential barrier 4 and drain region offer groove 41, groove 41 gos deep into Doped GaN resilient coating 2 from the surface of undoped AlGaN potential barrier 4 inner, in groove 41, growth has N-shaped InGaN epitaxial loayer 5, the N-shaped InGaN epitaxial loayer 5 of source region is formed with source electrode 6, the N-shaped InGaN epitaxial loayer 5 of drain region is formed with drain electrode 7.

In the present embodiment, source electrode 6 and drain electrode 7 are single or multiple lift metal, and multiple layer metal can be Ti/Al/Ni/Au structure.Being suitable for mutually with the semiconductor material system of GaNHEMT device of the work function of metals that source electrode 6 adopts with drain electrode 7.

Substrate 1 can be Si substrate, SiC substrate or Sapphire Substrate.

Doped with Si in N-shaped InGaN epitaxial loayer 5, doping content is 1 × 10 ¹⁹-5 × 10 ¹⁹.Further, in N-shaped InGaN epitaxial loayer 5, the content of In rises to 80% along with N-shaped InGaN epitaxial loayer 5 thickness increases from 0%.In content in N-shaped InGaN epitaxial loayer 5 is due to can up to 80%, therefore the energy gap of N-shaped InGaN epitaxial loayer 5 can lower than 1eV, and because the In content in N-shaped InGaN epitaxial loayer 5 is gradual change, so the unmatched problem of lattice can be reduced and then guarantee quality of materials.

Because source electrode 6 and drain electrode 7 are formed on N-shaped InGaN epitaxial loayer 5, so do not need to adopt high annealing to form ohmic contact, and ohmic contact resistance can far below the ohmic contact resistance adopting high annealing to realize.

The GaNHEMT device of the present embodiment, when specifically making, first forms the substrate 1, Doped GaN resilient coating 2, undoped GaN channel layer 3 and the undoped AlGaN potential barrier 4 that stack gradually from the bottom to top, then in undoped AlGaN potential barrier 4, makes SiO ₂mask, then to SiO ₂mask carries out dry etching, etches groove 41, and in groove 41, regrowth N-shaped InGaN epitaxial loayer 5, finally removes SiO ₂mask, and on the N-shaped InGaN epitaxial loayer 5 of source region and drain region, form source electrode 6 and drain electrode 7.

By the way, the GaNHEMT device of the non-alloyed ohmic contact of the utility model embodiment due to the energy gap of N-shaped InGaN epitaxial loayer can lower than 1eV, by forming source electrode and drain electrode on N-shaped InGaN epitaxial loayer, good non-alloyed ohmic contact can be formed, without the need to carrying out high annealing, thus high annealing can be avoided to bring lattice damage to GaN device, the Performance And Reliability of device can be improved, effective raising raceway groove two-dimensional electron gas, reduce ohmic contact layer surface and edge roughness, be conducive to the carrying out of subsequent technique.

The foregoing is only embodiment of the present utility model; not thereby the scope of the claims of the present utility model is limited; every utilize the utility model specification and accompanying drawing content to do equivalent structure or equivalent flow process conversion; or be directly or indirectly used in other relevant technical fields, be all in like manner included in scope of patent protection of the present utility model.

Claims

1. the GaNHEMT device of a non-alloyed ohmic contact, it is characterized in that, comprise the substrate stacked gradually from the bottom to top, Doped GaN resilient coating, undoped GaN channel layer and undoped AlGaN potential barrier, two-dimensional electron gas is formed between described undoped GaN channel layer and described undoped AlGaN potential barrier, source region and the drain region of described undoped AlGaN potential barrier offer groove, described groove gos deep into described Doped GaN resilient coating from the surface of described undoped AlGaN potential barrier inner, in described groove, growth has N-shaped InGaN epitaxial loayer, the N-shaped InGaN epitaxial loayer of described source region is formed with source electrode, the N-shaped InGaN epitaxial loayer of described drain region is formed with drain electrode.

2. the GaNHEMT device of non-alloyed ohmic contact according to claim 1, is characterized in that, described source electrode and described drain electrode are single or multiple lift metal.

3. the GaNHEMT device of non-alloyed ohmic contact according to claim 2, is characterized in that, described multiple layer metal is Ti/Al/Ni/Au.

4. the GaNHEMT device of non-alloyed ohmic contact according to claim 1, is characterized in that, described substrate is Si substrate, SiC substrate or Sapphire Substrate.