CN116741635A - HEMT device manufacturing method based on maskless regrowth low-resistance extension layer - Google Patents
HEMT device manufacturing method based on maskless regrowth low-resistance extension layer Download PDFInfo
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- 238000002161 passivation Methods 0.000 claims abstract description 23
- 238000002360 preparation method Methods 0.000 claims abstract description 13
- 238000002955 isolation Methods 0.000 claims abstract description 12
- 238000007667 floating Methods 0.000 claims abstract description 11
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- 230000003071 parasitic effect Effects 0.000 description 8
- 238000004891 communication Methods 0.000 description 7
- 230000005533 two-dimensional electron gas Effects 0.000 description 7
- 238000009616 inductively coupled plasma Methods 0.000 description 6
- 239000004065 semiconductor Substances 0.000 description 5
- 230000009286 beneficial effect Effects 0.000 description 4
- 238000001312 dry etching Methods 0.000 description 4
- 238000000623 plasma-assisted chemical vapour deposition Methods 0.000 description 4
- 230000005540 biological transmission Effects 0.000 description 3
- 230000015556 catabolic process Effects 0.000 description 3
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- H01L29/66227—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials the devices being controllable only by the electric current supplied or the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched, e.g. three-terminal devices
- H01L29/66409—Unipolar field-effect transistors
- H01L29/66446—Unipolar field-effect transistors with an active layer made of a group 13/15 material, e.g. group 13/15 velocity modulation transistor [VMT], group 13/15 negative resistance FET [NERFET]
- H01L29/66462—Unipolar field-effect transistors with an active layer made of a group 13/15 material, e.g. group 13/15 velocity modulation transistor [VMT], group 13/15 negative resistance FET [NERFET] with a heterojunction interface channel or gate, e.g. HFET, HIGFET, SISFET, HJFET, HEMT
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- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
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Abstract
The application discloses a preparation method of a HEMT device based on a maskless regrowth low-resistance extension layer, which comprises the following steps: epitaxially growing an N-face GaN/AlGaN heterojunction structure on a substrate; defining a source region and a drain region of the HEMT device on the surface of the N-face GaN/AlGaN heterojunction structure and forming a source region groove and a drain region groove; low temperature epitaxial growth of n + GaN material or n + An InGaN material, forming a maskless regrowth low-resistance extension layer; manufacturing a device isolation region; forming a source electrode and a drain electrode; forming a passivation layer; forming a grid groove; depositing a dielectric layer on the surface; and manufacturing a floating T-shaped gate based on the gate groove to obtain the HEMT device after manufacturing. The HEMT device prepared by the application can be used for a 6G terahertz frequency band.
Description
Technical Field
The application belongs to the field of semiconductors, and particularly relates to a preparation method of a HEMT (High electron mobility transistor ) device based on a maskless regrowth low-resistance extension layer.
Background
The 6G, sixth generation mobile communication technology, adopts terahertz frequency band (100 GHz-10 THz) communication, and compared with 5G communication (the low frequency band is Sub-6 GHz), the frequency of the communication frequency band is greatly improved, the corresponding network capacity can be greatly improved, the transmission capacity can be theoretically improved by 100 times, and the network delay can be correspondingly reduced from millisecond to microsecond.
In order to realize mass information and low-delay transmission, the frequency of a communication frequency band needs to be continuously increased to transition to a 6G technology based on terahertz frequency band communication. Based on this, the rf power device for future 6G communication applications needs to have good frequency characteristics, so that the device can operate in the W-band, and meanwhile, the device needs to have higher efficiency to reduce transmission loss.
In recent years, the third generation wide bandgap semiconductor material GaN has become the first choice material for preparing high-frequency and high-power radio frequency power devices by virtue of the advantages of large bandgap, high breakdown electric field strength and electron saturation speed. The GaN-based HEMT device is widely applied to key technical fields such as 5G base stations, satellites, radars and the like by means of high-concentration and high-mobility two-dimensional electron gas generated at a GaN/AlGaN heterojunction interface due to polarization induction. However, the application of the GaN-based HEMT device to 6G requires further enhancement of the operating frequency of such devices.
In the prior art, a GaN-based HEMT device is mostly prepared from Ga-surface GaN materials. By Ga-face GaN material, it is meant that the arrangement of crystal atoms in the material is non-centrally symmetric along the C-axis, with reference to Ga-N bonds parallel to the C-axis, the Ga atoms in each Ga-N bond being closer to the substrate. The method for improving the working frequency of the HEMT device mainly comprises the steps of shortening the gate length to the nanometer level and adopting ultrathin barriers such as strong polarization InAlN, alN and the like. However, in the process of gradually shortening the gate length of the device, a series of characteristics such as increased gate parasitic capacitance, poor gate control capability, short channel effect and the like, which deteriorate the performance of the device, occur. The adoption of the ultrathin barrier layer has a certain inhibition effect on the short channel effect, but can cause the increase of gate leakage to a certain extent, thereby affecting the efficiency of the device. Therefore, how to prepare a GaN-based HEMT device facing to future 6G terahertz frequency band communication is a technical problem to be solved urgently.
Disclosure of Invention
In order to solve the problems in the prior art, the application provides a preparation method of a HEMT device based on a maskless regrowth low-resistance extension layer.
The technical problems to be solved by the application are realized by the following technical scheme:
in a first aspect, the present application provides a method for preparing a HEMT device based on maskless regrowth of a low-resistance extension layer, including:
epitaxially growing an N-face GaN/AlGaN heterojunction structure on a substrate;
defining a source region and a drain region of the HEMT device on the surface of the N-face GaN/AlGaN heterojunction structure, etching the source region and the drain region downwards, and extending the etching depth into a barrier layer of the N-face GaN/AlGaN heterojunction structure to form a source region groove and a drain region groove;
low temperature epitaxial growth of n on the surface of the current sample + GaN material or n + InGaN material, so that the grown material fills the source region groove and the drain region groove and covers the surface of the N-face GaN/AlGaN heterojunction structure to form a maskless regrowth low-resistance extension layer;
manufacturing an isolation region of a device;
depositing ohmic metal on the surface of the maskless regrowth low-resistance extension layer right above the source region groove and the drain region groove to form a source electrode and a drain electrode;
forming a passivation layer on the surface of the current sample, and removing the passivation layers covered on the source electrode and the drain electrode;
defining a gate region of the HEMT device on the surface of the passivation layer between the source electrode and the drain electrode, etching the passivation layer and the maskless regrowing low-resistance extension layer in the gate region, and forming a gate groove;
depositing a dielectric layer on the surface of the current sample, and removing the dielectric layers covered on the source electrode and the drain electrode;
and manufacturing a floating T-shaped gate based on the gate groove to obtain the HEMT device after manufacturing.
In one embodiment, the substrate provided by the application comprises a SiC substrate, a Si substrate or a sapphire substrate.
In one embodiment, the N-plane GaN/AlGaN heterojunction structure comprises from bottom to top: the GaN buffer layer, the barrier layer, the GaN channel layer and the AlGaN cap layer.
In one embodiment, n in the maskless regrowth low resistance extension layer + GaN or n + InGaN doping concentration of 5×10 19 cm -3 Up to 5X 10 20 cm -3 。
In one embodiment, the fabricating the isolation region of the device includes: n, B or Ar ions are injected into two sides of the N-face GaN/AlGaN heterojunction structure, so that an isolation region of the device is formed.
In one embodiment, the ohmic metal is a metal stack structure formed by sequentially stacking Ti, al, ni and Au.
In one embodiment, the passivation layer includes: a SiN passivation layer.
In one embodiment, the dielectric layer includes: a SiN dielectric layer.
In a second aspect, the application provides a HEMT device based on a maskless regrowth low-resistance extension layer, which is prepared by any one of the preparation methods.
The preparation method of the HEMT device based on the maskless regrowth low-resistance extension layer has the following beneficial effects:
(1) In the application, an N-face GaN/AlGaN heterojunction structure is epitaxially grown on a substrate, and then an HEMT device is prepared based on the heterojunction structure. Therefore, the N-face GaN-based HEMT device is prepared. The gate metal of the N-face GaN-based HEMT can be directly deposited on the GaN channel layer and form metal-semiconductor contact with the channel layer to increase the gate control capability. Meanwhile, the control capability of the grid on the channel layer can be further modulated by controlling the thickness of the GaN channel layer without considering the thickness of the barrier layer, and the AlGaN layer is used as a natural back barrier layer, so that the limiting field of the two-dimensional electron gas can be further improved to inhibit the short channel effect. Therefore, the HEMT device prepared by the method has strong gate control capability, small short channel effect or no short channel effect. And the barrier layer in the N-face GaN/AlGaN heterojunction structure is positioned below the channel layer, so that the gate length is shorter, and the higher cut-off frequency is obtained. Therefore, the HEMT device prepared by the application can be used for a 6G terahertz frequency band.
(2) According to the application, the maskless regrowing low-resistance extension layer is prepared in the N-face GaN/AlGaN heterojunction structure, so that the ultra-short source-drain interval can be realized in the N-face GaN-based HEMT device, and the ultra-short source-drain interval can increase the movement path of electrons, so that the on-resistance and parasitic resistance of the device are effectively reduced.
(3) In the application, before the floating T-shaped gate is manufactured, a dielectric layer is deposited on the surface of the sample, and the dielectric layer has higher resistivity, so that the short circuit between the gate electrode and the source and drain electrodes can be prevented. Meanwhile, the high-resistivity dielectric layer is not beneficial to the passage of electrons, so that the gate leakage can be reduced. The smaller gate leakage can improve the breakdown voltage of the device, the off-state characteristic and the subthreshold characteristic of the device and the saturated leakage current of the device so as to improve the direct current characteristic of the device.
(4) The floating T-shaped grid can reduce the grid capacitance, the working frequency of the device can be improved by reducing the grid capacitance, and meanwhile, the manufacturing process of the floating T-shaped grid is mature and easy to manufacture.
In conclusion, the HEMT device based on the maskless regrowth low-resistance extension layer, which is prepared by the method, has higher working frequency, improves short channel effect, reduces on-resistance and parasitic resistance of the device, and has simple preparation process.
The present application will be described in further detail with reference to the accompanying drawings.
Drawings
Fig. 1 is a flowchart of a preparation method of a HEMT device based on maskless regrowth of a low-resistance extension layer provided by an embodiment of the present application;
fig. 2 to 10 are exploded views of a fabrication process of a HEMT device based on maskless regrowth of a low-resistance extension layer according to an embodiment of the present application;
fig. 11 is a schematic structural diagram of a HEMT device based on maskless regrowth of a low-resistance extension layer according to an embodiment of the present application.
Detailed Description
The present application will be described in further detail with reference to specific examples, but embodiments of the present application are not limited thereto.
Current gain cut-off frequency f of GaN-based HEMT device T Generally greater than the device operating frequency, determines the upper limit of the device operating frequency. Therefore, to increase the operating frequency of the device, f should be increased T The parameters are as follows:
wherein g m,int Representing intrinsic transconductance, C gs And C gd The gate source capacitance and the gate drain capacitance are respectively. If g of the device is increased m,int Parameters, while reducing gate parasitic capacitance, f T There is a significant increase in the parameters. g m,int The formula of the parameters is:
wherein I is ds To be the current between the drain and the source, V g Representing the voltage applied to the gate electrode of the device, V ds =ons means that the fixed inter-drain-source voltage is constant,when the inter-drain-source voltage is constant, the inter-drain-source current changes with the change of the gate electrode voltage, and μ represents the channel regionMobility of internal electrons, ε 0 Represents the vacuum dielectric constant, ε r Represents the relative dielectric constant, W, of the barrier layer g Representing the gate width of the device, L g Represents the gate length of the device, d represents the thickness of the barrier layer, V th Representing the threshold voltage of the device, v s The saturation velocity of electrons in the channel region.
Therefore, in the GaN-based HEMT device, the gate length L of the device is reduced g To lift the device g m,int And parameters are such that the operating frequency of the device is increased. However, as the gate length of the device is reduced to nanometer level, a series of adverse effects such as short channel effect can be generated, which is caused by the weakening of the two-dimensional electron gas control capability in the channel.
At present, more GaN-based HEMT devices are researched to adopt Ga-surface GaN materials, a layer of AlGaN barrier layer is arranged between a grid electrode and a channel of the Ga-surface GaN-based HEMT device, the distance from the grid electrode to the channel is not improved well so as to improve the grid control capability, and in the process that the grid length of the device is gradually shortened, a series of characteristics of deteriorating the device performance such as increase of the parasitic capacitance of the grid electrode, deterioration of the transconductance linearity, short channel effect and the like can occur. The adoption of the ultrathin barrier layer has a certain inhibition effect on the short channel effect, but can cause the increase of gate leakage to a certain extent, thereby affecting the efficiency of the device.
Due to the factors of limiting frequency characteristics and improving efficiency of the Ga-surface GaN-based HEMT device, it is particularly important to shorten the gate length of the device and simultaneously maintain good gate control capability so as to improve the working frequency of the device and reduce the parasitic resistance of the device so as to improve the working efficiency.
In order to achieve the above purpose, the embodiment of the application provides a preparation method of an HEMT device based on a maskless regrowth low-resistance extension layer, wherein an N-face GaN-based HEMT device is prepared by adopting an N-face GaN material. The polarity of the N-face GaN-based HEMT device is opposite to that of the Ga-face GaN-based HEMT device, and there are some natural advantages such as: the ohmic contact of the N-face GaN-based HEMT can be directly deposited on a GaN material with a smaller forbidden band width than AlGaN, which is helpful for realizing smaller ohmic contact resistance; the gate metal can be directly deposited on the GaN channel layer and form metal-semiconductor contact with the channel layer to increase the gate control capability, meanwhile, the control capability of the gate on the channel layer can be further modulated by controlling the thickness of the GaN channel layer without considering the thickness problem of the barrier layer, and the AlGaN layer is used as a natural back barrier layer, so that the limiting field of two-dimensional electron gas can be further improved to inhibit short channel effect.
The preparation method of the HEMT device based on the maskless regrowth low-resistance extension layer provided by the embodiment of the application is described in detail below.
Referring to fig. 1, the method comprises the steps of:
s1: and epitaxially growing an N-face GaN/AlGaN heterojunction structure on the substrate.
The substrate may include a SiC substrate, a Si substrate, or a sapphire substrate. The SiC substrate has good heat dissipation performance, and can improve the performance of the radio frequency high-power device; the Si substrate has mature process and large wafer size, and can reduce the cost of process equipment and single devices; the sapphire substrate can obtain better lattice matching, and the dislocation defect isodensity is reduced.
Referring to fig. 2, the N-plane GaN/AlGaN heterojunction structure includes, from bottom to top: the GaN buffer layer, the barrier layer, the GaN channel layer and the AlGaN cap layer. The dotted line in the GaN channel layer shows where the Two-dimensional electron gas (Two-Dimensional Electron Gas,2 DEG) is located, i.e., the main path of electrons from source to drain.
Specifically, an N-plane GaN/AlGaN heterojunction structure is epitaxially grown on a substrate, comprising: a GaN buffer layer, a barrier layer, a GaN channel layer, and an AlGaN cap layer were sequentially epitaxially grown on a substrate using a Metal-organic chemical vapor deposition (Metal-organic Chemical Vapor Deposition, MOCVD) apparatus.
Optionally, the GaN buffer layer includes, from bottom to top: fe or C doped high resistance GaN layer and Si doped n-type GaN layer.
Optionally, the barrier layer comprises Al arranged from bottom to top x Ga 1-x An N layer and a UID-AlGaN layer, wherein, al x Ga 1-x The N layer is a layer structure of AlGaN material doped with N-type Si and gradually changed in Al composition, and UID represents unintentional doping (unintentionally doped).
Wherein, preferablyThe Si doping concentration of the barrier layer may be 3.5X10 18 cm -3 Left and right to increase the areal density of 2DEG in the channel; the Al component is graded in the range of 5% -40%. The UID-AlGaN layer employs an unintentional doping process to isolate the doped n-type Si impurity from the 2DEG in the channel to reduce ionized impurity scattering of Si impurities on carriers in the 2 DEG.
S2: and defining a source region and a drain region of the HEMT device on the surface of the N-face GaN/AlGaN heterojunction structure, etching the source region and the drain region downwards, and extending the etching depth into a barrier layer of the N-face GaN/AlGaN heterojunction structure to form a source region groove and a drain region groove.
Specific: defining a source region and a drain region of the HEMT device on the surface of the N-face GaN/AlGaN heterojunction structure by adopting a photoetching method; and etching the source region and the drain region on the surface of the GaN-based heterojunction structure downwards by using an inductively coupled plasma spectrum generator (Inductive Coupled Plasma Emission Spectrometer, ICP) by using a dry etching process, wherein the etching depth extends into the barrier layer of the N-face GaN/AlGaN heterojunction structure. E.g., etched to at least 20nm below the barrier layer interface, to form source and drain trenches, see fig. 3, where 301 is the source trench and 302 is the drain trench.
S3: low temperature epitaxial growth of n on the surface of the current sample + GaN material or n + InGaN material, so that the grown material fills the source region groove and the drain region groove and covers the surface of the N-face GaN/AlGaN heterojunction structure, and a maskless regrowing low-resistance extension layer is formed.
Specific: low temperature epitaxial growth of n on current sample surfaces using molecular beam epitaxy (Molecular beam epitaxy, MBE) apparatus + GaN material or n + And (3) an InGaN material, so that the grown material fills the source region groove and the drain region groove and covers the surface of the N-face GaN/AlGaN heterojunction structure, and a maskless regrowth low-resistance extension layer is formed, as shown in fig. 4.
Preferably: epitaxially grown n + GaN or n + The doping concentration of the InGaN layer may be 5×10 19 cm -3 ～5×10 20 cm -3 。
S4: and manufacturing an isolation region of the device.
Specifically, N, B or Ar ions are injected into two sides of the N-face GaN/AlGaN heterojunction structure by using ion injection equipment to form an isolation region of the device, as shown in fig. 5.
S5: and depositing ohmic metal on the surface of the maskless regrowth low-resistance extension layer right above the source region groove and the drain region groove to form a source electrode and a drain electrode.
Specific: for example, ti, al, ni and Au are sequentially deposited on the surface of the maskless regrowth low-resistance extension layer right above the source region trench and the drain region trench of the current sample by using an electron beam evaporation process, so as to form a source electrode and a drain electrode, as shown in fig. 6.
S6: and forming a passivation layer on the surface of the current sample, and removing the passivation layer covered on the source electrode and the drain electrode.
Specific: a layer of SiN with a thickness of 20nm to 40nm is deposited on the surface of the current sample by using a plasma enhanced chemical vapor deposition (plasma enhanced chemical vapor deposition, PECVD) apparatus, and then passivation layers covered on the source electrode and the drain electrode are removed by using an ICP etching apparatus by using a dry etching process, as shown in fig. 7.
S7: and defining a gate region of the HEMT device on the surface of the passivation layer between the source electrode and the drain electrode, etching the passivation layer in the gate region and growing the low-resistance extension layer again without a mask to form a gate groove.
Specific: defining a gate region of the HEMT device on a passivation layer surface between a source electrode and a drain electrode by using electron-blocking layer (EBL) equipment; and a gate foot region needing to be etched is arranged below the gate region, a passivation layer and a maskless regrowth low-resistance extension layer in the gate foot region are etched by adopting a dry etching process through ICP etching equipment, and a gate groove is formed, as shown in figure 8, wherein 801 is a device gate groove.
Wherein the etching gas can be preferably SF 6 And BCl 3 So that self-terminating etching can be performed in the gate foot region. Because the etching gas cannot etch the Al-containing cap layer material, the etching gas can self-terminate when etching the AlGaN cap layer.
Exemplary embodimentsIn using SF 6 And BCl 3 When the mixed gas of (a) is subjected to self-termination etching, the gas SF 6 The flow rate of (2) was 10sccm, and the gas BCl 3 The flow rate of (2) is 30sccm, the pressure is 5mTorr, the ICP upper electrode power is 200W, and the lower electrode power is 30W.
S8: and depositing a dielectric layer on the surface of the current sample, and removing the dielectric layers covered on the source electrode and the drain electrode.
Specific: a layer of SiN with the thickness of 5nm is deposited on the surface of the current sample by utilizing a PECVD device, and then a dielectric layer covered on a source electrode and a drain electrode is removed by utilizing an ICP etching device by adopting a dry etching process, as shown in fig. 9.
S9, performing S9; and manufacturing a floating T-shaped gate based on the gate groove to obtain the HEMT device after manufacturing.
Specifically, two layers of photoresist are deposited on the surface of the device, and exposure is carried out twice, so that a T-shaped gate groove is formed in the gate region. And after depositing ohmic metal in the grid groove, preparing the floating T-shaped grid through photoresist stripping. The finished HEMT device is shown in fig. 10.
The preparation method of the HEMT device based on the maskless regrowth low-resistance extension layer provided by the embodiment of the application has the following beneficial effects:
(1) In the embodiment of the application, an N-face GaN/AlGaN heterojunction structure is epitaxially grown on a substrate, and then an HEMT device is prepared based on the heterojunction structure. Therefore, the N-face GaN-based HEMT device is prepared by the embodiment of the application. The gate metal of the N-face GaN-based HEMT can be directly deposited on the GaN channel layer and form metal-semiconductor contact with the channel layer to increase the gate control capability. Meanwhile, the control capability of the grid on the channel layer can be further modulated by controlling the thickness of the GaN channel layer without considering the thickness of the barrier layer, and the AlGaN layer is used as a natural back barrier layer, so that the limiting field of the two-dimensional electron gas can be further improved to inhibit the short channel effect. Therefore, the HEMT device prepared by the embodiment of the application has stronger gate control capability, smaller short channel effect or no short channel effect. And the barrier layer in the N-face GaN/AlGaN heterojunction structure is positioned below the channel layer, so that the gate length is shorter, and the higher cut-off frequency is obtained. Therefore, the HEMT device prepared by the application can be used for a 6G terahertz frequency band.
(2) According to the embodiment of the application, the maskless regrowing low-resistance extension layer is prepared in the N-face GaN/AlGaN heterojunction structure, so that the ultra-short source-drain interval can be realized in the N-face GaN-based HEMT device, and the ultra-short source-drain interval can increase the movement path of electrons, so that the on-resistance and parasitic resistance of the device are effectively reduced.
(3) In the embodiment of the application, before the floating T-shaped gate is manufactured, a dielectric layer is deposited on the surface of the sample, and the dielectric layer has higher resistivity, so that the short circuit between the gate electrode and the source and drain electrodes can be prevented. Meanwhile, the high-resistivity dielectric layer is not beneficial to the passage of electrons, so that the gate leakage can be reduced. The smaller gate leakage can improve the breakdown voltage of the device, the off-state characteristic and the subthreshold characteristic of the device and the saturated leakage current of the device so as to improve the direct current characteristic of the device.
(4) The floating T-shaped gate adopted in the embodiment of the application can reduce the gate capacitance, and the reduction of the gate capacitance can improve the working frequency of the device, and meanwhile, the manufacturing process of the floating T-shaped gate is mature and easy to manufacture.
The embodiment of the application also provides a HEMT device based on the maskless regrowth low-resistance extension layer, which is prepared by adopting any preparation method of the HEMT device based on the maskless regrowth low-resistance extension layer. Referring to fig. 11, fig. 11 is a schematic structural diagram of a HEMT device manufactured by using the manufacturing method provided by the embodiment of the present application. As shown in fig. 11, a HEMT device based on maskless regrowth of a low-resistance extension layer provided by an embodiment of the present application includes: substrate, gaN buffer layer, barrier layer, gaN channel layer, alGaN cap layer, n + GaN material or n + The maskless regrowth low-resistance extension layer, the source electrode, the drain electrode, the gate electrode, the passivation layer, the dielectric layer and the isolation region are formed by InGaN materials.
Wherein, the substrate, the GaN buffer layer, the barrier layer, the GaN channel layer and the AlGaN cap layer are sequentially laminated from bottom to top; n is n + GaN material or n + A maskless regrowth low-resistance extension layer formed by InGaN material is arranged on the AlGaN barrier layer, a source electrode and a leakage electrodeUnder the electrode and extending to the gate electrode side; the source electrode and the drain electrode are respectively arranged on the maskless regrowth low-resistance extension layer; the gate electrode is arranged above the dielectric layer and is positioned between the source electrode and the drain electrode; the passivation layer covers the maskless regrowth low-resistance extension layer and the isolation region; the dielectric layer covers the AlGaN cap layer, the maskless regrowth low-resistance extension layer and the passivation layer; the isolation regions are located on both sides of the device.
According to the HEMT device based on the maskless regrowth low-resistance extension layer, which is provided by the embodiment of the application, the maskless regrowth low-resistance extension layer is arranged in the N-face GaN/AlGaN heterojunction structure, so that the parasitic resistance of the device can be greatly reduced, the working frequency of the device can be effectively improved, and the HEMT device based on the maskless regrowth low-resistance extension layer can be applied to a 6G terahertz frequency band.
Although the application has been described herein in connection with the embodiments, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed application, from a study of the drawings and the disclosure.
The foregoing is a further detailed description of the application in connection with the preferred embodiments, and it is not intended that the application be limited to the specific embodiments described. It will be apparent to those skilled in the art that several simple deductions or substitutions may be made without departing from the spirit of the application, and these should be considered to be within the scope of the application.
Claims (9)
1. A preparation method of a HEMT device based on a maskless regrowth low-resistance extension layer is characterized by comprising the following steps:
epitaxially growing an N-face GaN/AlGaN heterojunction structure on a substrate;
defining a source region and a drain region of the HEMT device on the surface of the N-face GaN/AlGaN heterojunction structure, etching the source region and the drain region downwards, and extending the etching depth into a barrier layer of the N-face GaN/AlGaN heterojunction structure to form a source region groove and a drain region groove;
low temperature epitaxial growth of n on the surface of the current sample + GaN material or n + InGaN material, so that the grown material fills the source region groove and the drain region groove and covers the surface of the N-face GaN/AlGaN heterojunction structure to form a maskless regrowth low-resistance extension layer;
manufacturing an isolation region of a device;
depositing ohmic metal on the surface of the maskless regrowth low-resistance extension layer right above the source region groove and the drain region groove to form a source electrode and a drain electrode;
forming a passivation layer on the surface of the current sample, and removing the passivation layers covered on the source electrode and the drain electrode;
defining a gate region of the HEMT device on the surface of the passivation layer between the source electrode and the drain electrode, etching the passivation layer and the maskless regrowing low-resistance extension layer in the gate region, and forming a gate groove;
depositing a dielectric layer on the surface of the current sample, and removing the dielectric layers covered on the source electrode and the drain electrode;
and manufacturing a floating T-shaped gate based on the gate groove to obtain the HEMT device after manufacturing.
2. The method of manufacturing according to claim 1, wherein the substrate comprises a SiC substrate, a Si substrate, or a sapphire substrate.
3. The method of claim 1, wherein the N-plane GaN/AlGaN heterojunction structure comprises from bottom to top: the GaN buffer layer, the barrier layer, the GaN channel layer and the AlGaN cap layer.
4. The method of claim 1, wherein n in the maskless regrowth low resistance extension layer + GaN or n + InGaN doping concentration of 5×10 19 cm -3 Up to 5X 10 20 cm -3 。
5. The method of manufacturing of claim 1, wherein the fabricating the isolation region of the device comprises:
n, B or Ar ions are injected into two sides of the N-face GaN/AlGaN heterojunction structure, so that an isolation region of the device is formed.
6. The method according to claim 1, wherein the ohmic metal is a metal stack structure formed by sequentially stacking Ti, al, ni and Au.
7. The method of manufacturing of claim 1, wherein the passivation layer comprises: a SiN passivation layer.
8. The method of manufacturing of claim 1, wherein the dielectric layer comprises: a SiN dielectric layer.
9. A HEMT device based on a maskless regrowth low-resistance extension layer, which is characterized in that the HEMT device is prepared by adopting the preparation method of the HEMT device based on the maskless regrowth low-resistance extension layer as set forth in any one of claims 1-8.
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| CN118398492A (en) * | 2024-06-28 | 2024-07-26 | 合肥欧益睿芯科技有限公司 | Enhanced GaAs HEMT device, manufacturing method thereof and electronic equipment |
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| CN118398492A (en) * | 2024-06-28 | 2024-07-26 | 合肥欧益睿芯科技有限公司 | Enhanced GaAs HEMT device, manufacturing method thereof and electronic equipment |
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