CN105352636A - GaN pressure sensor device and manufacturing method thereof - Google Patents

GaN pressure sensor device and manufacturing method thereof Download PDF

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CN105352636A
CN105352636A CN201510765592.0A CN201510765592A CN105352636A CN 105352636 A CN105352636 A CN 105352636A CN 201510765592 A CN201510765592 A CN 201510765592A CN 105352636 A CN105352636 A CN 105352636A
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pressure sensor
source electrode
passivation layer
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CN105352636B (en
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陈一峰
陈汝钦
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Chengdu Gastone Technology Co Ltd
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Chengdu Gastone Technology Co Ltd
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Abstract

The invention provides a GaN pressure sensor device and a manufacturing method thereof. The device comprises a substrate, an AlN buffer layer, a GaN transition layer, an AlN separating layer, an AlxGa1-xN Schottky barrier layer and a GaN cap layer which are formed successively from bottom to top, the transition layer and the Schottky barrier layer form a 2D electron gas, the 2D electron gas is placed between the transition layer and the separating layer, the GaN cap layer is provided with an isolation region, the isolation region is embedded into the upper surface of the GaN cap layer and extends into the internal of the GaN transition layer, the isolation region divides the GaN cap layer into a sensing area and a device area, passivation layers with tensile stress are grown on the sensing area and the device area respectively, a TaN transmission line is deposited at the surface of the passivation layer of the sensing area, and grid, source and drain electrodes are formed on the passivation layer of the device area, and formed on the GaN cap layer by penetrating the passivation layer. The GaN pressure sensor device can detect the pressure in extreme environments.

Description

GaN pressure sensor and preparation method thereof
Technical field
The present invention relates to field of semiconductor devices, particularly relate to a kind of GaN pressure sensor and preparation method thereof.
Background technology
TaN material has excellent pressure and becomes characteristic, there is high high-temperature stability (fusing point is at about 3000 DEG C), lower temperature-coefficient of electrical resistance, excellent hardness and wearing quality simultaneously, use the pressure transducer of TaN material to have a wide range of applications in fields such as aircraft, high-speed train, automobile, petroleum detections potentiality.GaN material is as the Typical Representative of wide bandgap semiconductor, there is the advantages such as working temperature is high, power stage density is large, high frequency performance good, capability of resistance to radiation is strong, GaNHEMT (HighElectronMobilityTransistor, High Electron Mobility Transistor) device is now widely used third generation semiconductor devices, degree of ripeness is high, realizes technique relatively stable.
Therefore, TaN pressure transducer is combined with GaNHEMT device can realize pressure sensing, signal amplifies and Signal transmissions.But in actual applications, TaN pressure transducer and GaNHEMT device are discrete devices, this is unfavorable for that device is integrated and reduce costs.
Summary of the invention
The technical matters that the present invention mainly solves is to provide a kind of GaN pressure sensor and preparation method thereof, can realize the pressure detection of extreme environment.
For solving the problems of the technologies described above, the technical scheme that the present invention adopts is: provide a kind of GaN pressure sensor, comprise the substrate, AlN cushion, GaN transition layer, AlN separation layer, the Al that are from bottom to top formed successively xga 1-xn schottky barrier layer and GaN cap, described GaN transition layer and described Al xga 1-xn schottky barrier layer forms two-dimensional electron gas, described two-dimensional electron gas is between described GaN transition layer and described AlN separation layer, described GaN cap is provided with isolated area, described isolated area embeds from the upper surface of described GaN cap and extends to described GaN transition layer inside, described isolated area is separated out sensitive zones and device area in described GaN cap, described sensitive zones and device area all grow the passivation layer having and have tension stress, the passivation layer surface of described sensitive zones deposits TaN transmission line, the passivation layer of described device area is formed with grid, source electrode and drain electrode, described drain electrode is between described isolated area and described source electrode, described grid is between described source electrode and described drain electrode, described grid, source electrode and drain electrode are all formed in described GaN cap through described passivation layer.
Preferably, described grid, source electrode and drain electrode all form Ohmic contact by high annealing and described GaN cap.
Preferably, the shape of described TaN transmission line is snakelike.
Preferably, the material of described substrate is Si, SiC, GaN, sapphire or Diamond.
Preferably, the thickness of described AlN cushion is 10-500nm.
Preferably, the thickness 500-3000nm of described GaN transition layer, the material of described GaN transition layer is N-type GaN, and doping content is less than or equal to 5 × 10 17cm -3.
Preferably, the thickness of described AlN separation layer is 1-5nm.
Preferably, Al xga 1-xthe thickness of N schottky barrier layer is the scope of 15-40nm, X is 0.1-0.3, and doping content is less than or equal to 1 × 10 18cm -3.
Preferably, the material of described passivation layer is SiNx or SiO 2, thickness is 20-200nm.
For solving the problems of the technologies described above, another technical solution used in the present invention is: provide a kind of according to any one the method for making of GaN pressure sensor above-mentioned, comprise the following steps: on substrate, from bottom to top form AlN cushion, GaN transition layer, AlN separation layer, Al successively xga 1-xn schottky barrier layer, GaN cap and passivation layer, wherein, described GaN transition layer and described Al xga 1-xn schottky barrier layer forms two-dimensional electron gas, and described two-dimensional electron gas is between described GaN transition layer and described AlN separation layer; Carry out etching to expose described GaN cap at described passivation layer, and isolated area is set at the described GaN cap place etched, wherein, described isolated area embeds from the upper surface of described GaN cap and extends to described GaN transition layer inside, and described isolated area is separated out sensitive zones and device area in described GaN cap; At the passivation layer surface deposition TaN transmission line of described sensitive zones, and grid, source electrode and drain electrode is formed on the passivation layer of described device area, wherein, described drain electrode is between described isolated area and described source electrode, described grid is between described source electrode and described drain electrode, and described grid, source electrode and drain electrode are all formed in described GaN cap through described passivation layer.
Be different from the situation of prior art, the invention has the beneficial effects as follows:
1. compared with traditional pressure transducer, working temperature is higher, can normally work in extreme circumstances
2. integrated level is high, is conducive to reducing pressure sensor systems volume and reducing costs.
The resistivity of 3.TaN transmission line can be regulated by the depositing temperature of adjustment TaN transmission line.
4. sensor is functionally separated with receiver, can effectively reduce volume, can detect pressure parameter certificate on the basis not affecting original aerodynamics, fluid mechanical design.
Accompanying drawing explanation
Fig. 1 is the structural representation of embodiment of the present invention GaN pressure sensor.
Fig. 2 ~ Fig. 3 is the preparation flow figure of embodiment of the present invention GaN pressure sensor.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, be clearly and completely described the technical scheme in the embodiment of the present invention, obviously, described embodiment is only a part of embodiment of the present invention, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.
Referring to Fig. 1, is the structural representation of embodiment of the present invention GaN pressure sensor.The GaN pressure sensor of the embodiment of the present invention comprises the substrate 10, AlN cushion 20, GaN transition layer 30, AlN separation layer 40, the Al that are from bottom to top formed successively xga 1-xn schottky barrier layer 50 and GaN cap 60, GaN transition layer 30 and Al xga 1-xn schottky barrier layer 50 forms two-dimensional electron gas 31, two-dimensional electron gas 31 is between GaN transition layer 3 and AlN separation layer 40, GaN cap 60 is provided with isolated area 61, isolated area 61 embeds from the upper surface of GaN cap 60 and extends to GaN transition layer 30 inside, isolated area 61 is separated out sensitive zones and device area in GaN cap 60, sensitive zones and device area all grow the passivation layer 70 having and have tension stress, passivation layer 70 surface deposition of sensitive zones has TaN transmission line 80, the passivation layer 70 of device area is formed with grid 91, source electrode 92 and drain electrode 93, drain electrode 93 is between isolated area 61 and source electrode 92, grid 91 is between source electrode 92 and drain electrode 93, grid 91, source electrode 92 and drain electrode 93 are all formed in GaN cap 60 through passivation layer 70.In the present embodiment, grid 91, source electrode 92 and drain electrode 93 all form Ohmic contact by high annealing and GaN cap 60.
Wherein, because passivation layer 70 has tension stress, therefore under polarization characteristic, two-dimensional electron gas 31 is created.In the present embodiment, the material of passivation layer 70 is SiNx or SiO 2, thickness is 20-200nm.
The effect of isolated area 61 makes sensitive zones and device area carry out electrical isolation, makes both mutually insulateds.Isolated area 61 can adopt to be injected ionic means or adopts etching technics to be formed.
TaN transmission line 80 can adopt masking process at N 2sputter TaN under protective atmosphere to obtain, also can adopt at N 2first sputter TaN under protective atmosphere, then expose and etch and obtain.The shape of TaN transmission line 80 can be snakelike, and length can be arranged arbitrarily.
The material of substrate 10 is Si, SiC, GaN, sapphire or Diamond, and it mainly plays a supportive role.The thickness of AlN cushion 20 is 10-500nm.
The thickness 500-3000nm of GaN transition layer 30, the material of GaN transition layer 30 is N-type GaN, and doping content is less than or equal to 5 × 10 17cm -3.
The thickness of AlN separation layer 40 is 1-5nm, and Main Function is separated with AlxGa1-xN schottky barrier layer 50 GaN transition layer 30.
Al xga 1-xthe thickness of N schottky barrier layer 50 is the scope of 15-40nm, X is 0.1-0.3, and doping content is less than or equal to 1 × 10 18cm -3.
The embodiment of the present invention also provides a kind of method for making of GaN pressure sensor, refers to Fig. 2 to Fig. 3, and this method for making comprises the following steps:
Step one: from bottom to top form AlN cushion 20, GaN transition layer 30, AlN separation layer 40, Al successively over the substrate 10 xga 1-xn schottky barrier layer 50, GaN cap 60 and passivation layer 70, wherein, GaN transition layer 30 and Al xga 1-xn schottky barrier layer 50 forms two-dimensional electron gas 31, and two-dimensional electron gas 31 is between GaN transition layer 30 and AlN separation layer 40.
Wherein, as shown in Figure 2, substrate 10, AlN cushion 20, GaN transition layer 30, AlN separation layer 40, Al xga 1-xn schottky barrier layer 50, GaN cap 60 and the structure of passivation layer 70 for stacking gradually.
The material of substrate 10 is Si, SiC, GaN, sapphire or Diamond, and it mainly plays a supportive role.
The thickness of AlN cushion 20 is 10-500nm.
The thickness 500-3000nm of GaN transition layer 30, the material of GaN transition layer 30 is N-type GaN, and doping content is less than or equal to 5 × 10 17cm -3.
The thickness of AlN separation layer 40 is 1-5nm, and Main Function is by GaN transition layer 30 and Al xga 1-xn schottky barrier layer 50 is separated.Al xga 1-xthe thickness of N schottky barrier layer 50 is the scope of 15-40nm, X is 0.1-0.3, and doping content is less than or equal to 1 × 10 18cm -3.
The material of passivation layer 70 is SiNx or SiO 2, thickness is 20-200nm.Passivation layer 70 has tension stress, therefore under polarization characteristic, creates two-dimensional electron gas 31.
Step 2: carry out etching to expose GaN cap 60 at passivation layer 70, and isolated area 61 is set at GaN cap 60 place etched, wherein, isolated area 61 embeds from the upper surface of GaN cap 60 and extends to GaN transition layer 30 inside, and isolated area 61 is separated out sensitive zones and device area in GaN cap 60.
Wherein, the effect of isolated area 61 makes sensitive zones and device area carry out electrical isolation, makes both mutually insulateds.Isolated area 61 can adopt to be injected ionic means or adopts etching technics to be formed, and the shape of isolated area 61 as shown in Figure 3.
Step 3: at the passivation layer 70 surface deposition TaN transmission line 80 of sensitive zones, and on the passivation layer 70 of device area, form grid 91, source electrode 92 and drain electrode 93, wherein, drain electrode 93 is between isolated area 61 and source electrode 92, grid 91 is between source electrode 92 and drain electrode 93, and grid 91, source electrode 92 and drain electrode 93 are all formed in GaN cap 60 through passivation layer 70.
Wherein, after step 3, namely the GaN pressure sensor shown in Fig. 1 is obtained, TaN transmission line 80 and grid 91, source electrode 92 and drain and 93 lay respectively at isolated area 61 both sides, TaN transmission line 80 has strain effect, the resistance value of TaN transmission line 80 can change and marked change along with pressure, thus produces piezoelectric signal.In the present embodiment, step 3 also comprises: carry out high annealing to grid 91, source electrode 92 and drain electrode 93, forms Ohmic contact to make grid 91, source electrode 92 and drain electrode 93 with GaN cap 60.
By the way, TaN pressure transducer and GaNHEMT device integrate by GaN pressure sensor of the embodiment of the present invention and preparation method thereof, but they are functionally separated from each other again, thus can realize the pressure detection of extreme environment.
The foregoing is only embodiments of the invention; not thereby the scope of the claims of the present invention is limited; every utilize instructions of the present invention 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 invention.

Claims (10)

1. a GaN pressure sensor, is characterized in that, comprises the substrate, AlN cushion, GaN transition layer, AlN separation layer, the Al that are from bottom to top formed successively xga 1-xn schottky barrier layer and GaN cap, described GaN transition layer and described Al xga 1-xn schottky barrier layer forms two-dimensional electron gas, described two-dimensional electron gas is between described GaN transition layer and described AlN separation layer, described GaN cap is provided with isolated area, described isolated area embeds from the upper surface of described GaN cap and extends to described GaN transition layer inside, described isolated area is separated out sensitive zones and device area in described GaN cap, described sensitive zones and device area all grow the passivation layer having and have tension stress, the passivation layer surface of described sensitive zones deposits TaN transmission line, the passivation layer of described device area is formed with grid, source electrode and drain electrode, described drain electrode is between described isolated area and described source electrode, described grid is between described source electrode and described drain electrode, described grid, source electrode and drain electrode are all formed in described GaN cap through described passivation layer.
2. GaN pressure sensor according to claim 1, is characterized in that, described grid, source electrode and drain electrode all form Ohmic contact by high annealing and described GaN cap.
3. GaN pressure sensor according to claim 1, is characterized in that, the shape of described TaN transmission line is snakelike.
4. GaN pressure sensor according to claim 1, is characterized in that, the material of described substrate is Si, SiC, GaN, sapphire or Diamond.
5. GaN pressure sensor according to claim 1, is characterized in that, the thickness of described AlN cushion is 10-500nm.
6. GaN pressure sensor according to claim 1, is characterized in that, the thickness 500-3000nm of described GaN transition layer, and the material of described GaN transition layer is N-type GaN, and doping content is less than or equal to 5 × 10 17cm -3.
7. GaN pressure sensor according to claim 1, is characterized in that, the thickness of described AlN separation layer is 1-5nm.
8. GaN pressure sensor according to claim 1, is characterized in that, described Al xga 1-xthe thickness of N schottky barrier layer is the scope of 15-40nm, X is 0.1-0.3, and doping content is less than or equal to 1 × 10 18cm -3.
9. GaN pressure sensor according to claim 1, is characterized in that, the material of described passivation layer is SiNx or SiO 2, thickness is 20-200nm.
10. a method for making for the GaN pressure sensor according to any one of claim 1-9, is characterized in that, comprise the following steps:
Substrate from bottom to top forms AlN cushion, GaN transition layer, AlN separation layer, Al successively xga 1-xn schottky barrier layer, GaN cap and passivation layer, wherein, described GaN transition layer and described Al xga 1-xn schottky barrier layer forms two-dimensional electron gas, and described two-dimensional electron gas is between described GaN transition layer and described AlN separation layer;
Carry out etching to expose described GaN cap at described passivation layer, and isolated area is set at the described GaN cap place etched, wherein, described isolated area embeds from the upper surface of described GaN cap and extends to described GaN transition layer inside, and described isolated area is separated out sensitive zones and device area in described GaN cap;
At the passivation layer surface deposition TaN transmission line of described sensitive zones, and grid, source electrode and drain electrode is formed on the passivation layer of described device area, wherein, described drain electrode is between described isolated area and described source electrode, described grid is between described source electrode and described drain electrode, and described grid, source electrode and drain electrode are all formed in described GaN cap through described passivation layer.
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CN108682734A (en) * 2018-04-04 2018-10-19 华南理工大学 A kind of gallium nitride based sensor of integrated peripheral circuit and preparation method thereof

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