CN113594021A - Manufacturing method of silicon-based GaN-HEMT epitaxial structure - Google Patents

Manufacturing method of silicon-based GaN-HEMT epitaxial structure Download PDF

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CN113594021A
CN113594021A CN202110825054.1A CN202110825054A CN113594021A CN 113594021 A CN113594021 A CN 113594021A CN 202110825054 A CN202110825054 A CN 202110825054A CN 113594021 A CN113594021 A CN 113594021A
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gan
layer
epitaxial structure
carrier gas
hemt
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韩甲俊
孙明
庄文荣
颜建锋
敖辉
陈兴虎
严鹏
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Sino Nitride Semiconductor Co Ltd
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Sino Nitride Semiconductor Co Ltd
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    • C30B25/00—Single-crystal growth by chemical reaction of reactive gases, e.g. chemical vapour-deposition growth
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    • C30B25/00—Single-crystal growth by chemical reaction of reactive gases, e.g. chemical vapour-deposition growth
    • C30B25/02—Epitaxial-layer growth
    • C30B25/18—Epitaxial-layer growth characterised by the substrate
    • C30B25/186—Epitaxial-layer growth characterised by the substrate being specially pre-treated by, e.g. chemical or physical means
    • C—CHEMISTRY; METALLURGY
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    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/10—Inorganic compounds or compositions
    • C30B29/40—AIIIBV compounds wherein A is B, Al, Ga, In or Tl and B is N, P, As, Sb or Bi
    • C30B29/403—AIII-nitrides
    • C30B29/406—Gallium nitride
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    • H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof  ; Multistep manufacturing processes therefor
    • H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
    • H01L29/66007—Multistep manufacturing processes
    • H01L29/66075—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials
    • 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

Abstract

The invention provides a manufacturing method of a silicon-based GaN-HEMT epitaxial structure, which comprises the following steps: forming a GaN-HEMT epitaxial structure on a silicon substrate by adopting a metal organic chemical vapor deposition process, wherein the GaN-HEMT epitaxial structure comprises a nucleating layer, a buffer layer, a carbon-doped GaN high-resistance layer, a non-doped GaN channel layer, an AlN spatial layer, an AlGaN barrier layer and a GaN cap layer; the gas source adopted by the epitaxial growth of the GaN-HEMT epitaxial structure comprises an organic metal source and a nitrogen source, and H is used as the gas source2And N2As carrier gas, among others, carrier gas H of nitrogen source2And N2The volume ratio of (A) is 1.75-2.5, and the carrier gas H of the organic metal source2And N2The volume ratio of (A) to (B) is 0.4 to 1. The invention can effectively improve the growth rate uniformity and the thickness uniformity of different areas, the Al component uniformity of the AlGaN barrier layer, the 2DEG density and the mobility of two-dimensional electron gas in the epitaxial growth process of the GaN-HEMT.

Description

Manufacturing method of silicon-based GaN-HEMT epitaxial structure
Technical Field
The invention belongs to the field of design and manufacture of semiconductor devices, and particularly relates to a manufacturing method of a silicon-based GaN-HEMT epitaxial structure.
Background
With the development of third-generation semiconductor power electronic devices, gallium nitride (GaN) has attracted attention as a representative third-generation semiconductor material for researchers in various countries. Compared with a Si device, the GaN power device has the advantages that (1) the forbidden band width is large (3.39eV), the GaN power device can adapt to a high-temperature field and a high-electric field, the cooling cost is reduced, and the equipment volume is reduced; high breakdown electric field (4E 6V/cm) can bear higher power, and under the same breakdown voltage, the GaN device depletion region is smaller in length and lower in power consumption; high electron mobility (1000-2000 cm 2/V.s), high electron saturation drift rate (2.5E7cm/s), low power consumption and high power output density under a high field.
The GaN material has a great advantage that the GaN material has polarization (spontaneous polarization and piezoelectric polarization) effect, and can form a large amount of polarized positive charges on an AlGaN/GaN heterojunction interface, so that Two-Dimensional Electron Gas (2 DEG) with very high surface density exists in the AlGaN/GaN heterojunction quantum, the surface density is usually 10E13cm-2 magnitude, and the mobility is very high and can reach 2000cm 2/V.s. Therefore, the AlGaN/GaN High Electron Mobility Transistor (HEMT) based on the GaN material has significant advantages, has a wide application prospect in the fields of phased array radar, electronic countermeasure, 5G communication, automotive electronics, and the like, and has become the focus of current international academic and industrial fields.
Research and application of AlGaN/GaN HEMTs have made many breakthrough advances, but still face a number of difficulties, such as defects and impurities in the epitaxial material, ohmic contact problems, surface passivation problems, device stability and reliability problems, etc. The performance problems of most devices are caused by the poor growth condition of epitaxial materials, wherein the crystal quality of AlGaN/GaN heterogeneous materials, the content of Al components in AlGaN barrier layers, the thickness of barrier layers and other properties can directly influence the mobility of two-dimensional electron gas of HEMT structural materials, and the influence on the device performance is great. More importantly, because Al atoms on the surface are difficult to move in the growth process, when a large-size HEMT epitaxial wafer is grown, the thickness uniformity of the epitaxial wafer and the uniformity of Al components in the AlGaN barrier layer are poor, so that the stability and the reliability of the device are problematic.
Disclosure of Invention
In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a method for fabricating a silicon-based GaN-HEMT epitaxial structure, which is used to solve the problems of poor uniformity of thickness of the GaN-HEMT epitaxial structure and poor uniformity of Al composition in the AlGaN barrier layer in the prior art.
In order to achieve the above and other related objects, the present invention provides a method for fabricating a silicon-based GaN-HEMT epitaxial structure, the method comprising: providing a silicon substrate; forming a GaN-HEMT epitaxial structure on the silicon substrate by adopting a metal organic chemical vapor deposition process, comprising the following steps of: epitaxially growing a nucleation layer on the silicon substrate; epitaxially growing a buffer layer on the nucleation layer; epitaxially growing a carbon-doped GaN high-resistance layer on the buffer layer; epitaxially growing a non-doped GaN channel layer on the carbon-doped GaN high-resistance layer; epitaxially growing an AlN spatial layer on the non-doped GaN channel layer; epitaxially growing an AlGaN barrier layer on the AlN space layer; epitaxially growing a GaN cap layer on the AlGaN barrier layer; the gas source adopted by the epitaxial growth of the GaN-HEMT epitaxial structure comprises an organic metal source and a nitrogen source, wherein the organic metal source and the nitrogen source are both H2And N2As carrier gas, wherein the carrier gas H of the nitrogen source2And N2The volume ratio of (A) to (B) is 1.75-2.5, and the carrier gas H of the organic metal source2And N2The volume ratio of (A) to (B) is 0.4 to 1.
Optionally, the epitaxial growth thickness uniformity of the GaN-HEMT epitaxial structure is less than or equal to 1%.
Further, a carrier gas H for the nitrogen source2And N2The volume ratio of (a) is 2.2-2.3, so that the epitaxial growth thickness uniformity of the GaN-HEMT epitaxial structure is less than or equal to 0.5%.
Optionally, the epitaxial growth of the undoped GaN channel layer uses trimethylgallium as a gallium source, NH3As nitrogen source, H2And N2As carrier gas, wherein the carrier gas H of the nitrogen source2And N2Is 1.75 to 2.5, so that the growth rate uniformity of the undoped GaN channel layer is less than or equal to 1%.
Optionally, the epitaxial growth of the AlGaN barrier layer uses trimethyl gallium and trimethyl aluminum as a gallium source and an aluminum source, respectively, NH3As nitrogen source, H2And N2As a carrier gas, wherein the carrier gas H of trimethyl gallium and trimethyl aluminum2And N2Is 0.4 to 1, so that the Al component uniformity of the AlGaN barrier layer is less than or equal to 1%.
Optionally, the epitaxial growth of the AlGaN barrier layer uses trimethyl gallium and trimethyl aluminum as a gallium source and an aluminum source, respectively, NH3As nitrogen source, H2And N2As a carrier gas, wherein the carrier gas H of trimethyl gallium and trimethyl aluminum2And N2The volume ratio of (A) to (B) is 0.4-1, so that the 2DEG mobility of the GaN-HEMT epitaxial structure is larger than or equal to 1800cm2Has an areal density of 8.5E12cm or more-2。
Further, the carrier gas H of trimethyl gallium and trimethyl aluminum2And N2The volume ratio of (A) to (B) is 0.7-0.8, so that the 2DEG mobility of the GaN-HEMT epitaxial structure is larger than 1900cm2/V·s。
Optionally, the spray header used in the metal organic chemical vapor deposition process includes a middle region air outlet and an edge air outlet surrounding the middle region air outlet, and the middle region air outlet and the edge air outlet are independently controlled.
Optionally, providing a silicon substrate is further followed by providing H2And carrying out heat treatment on the silicon substrate under the atmosphere to remove the oxide on the surface of the silicon substrate.
Optionally, the nucleation layer comprises an AlN nucleation layer, and the buffer layer comprises a plurality of AlGaN buffer layers, wherein the Al composition in the plurality of AlGaN buffer layers is gradually reduced.
As described above, the method for manufacturing the silicon-based GaN-HEMT epitaxial structure of the present invention has the following beneficial effects:
the invention adjusts H when the MOCVD epitaxy grows the GaN-HEMT epitaxy structure2/N2The carrier gas ratio improves the growth rate uniformity and the thickness uniformity of different areas, the Al component uniformity of the AlGaN barrier layer, the 2DEG surface density and the mobility of two-dimensional electron gas in the epitaxial growth process of the silicon-based AlGaN/GaN HEMT.
NH during GaN growth3Carrier gas H of2/N2When the ratio is between 1.75 and 2.5, the thickness uniformity of the whole epitaxial layer can be below 1%, wherein the carrier gas H2/N2At a ratio of 2.25, the thickness uniformity is optimally 0.44%.
Carrier gas H of organic metal source in growth process of AlGaN barrier layer2/N2When the ratio is between 0.5 and 1, the Al component uniformity of the AlGaN barrier layer can be below 1%, wherein the carrier gas H2/N2At a ratio of 2.25, the Al composition uniformity is optimally 0.99%.
Carrier gas H of organic metal source in growth process of AlGaN barrier layer2/N2When the ratio is between 0.5 and 1, the 2DEG surface density of the epitaxial wafer at the center position, the middle ring position and the edge position is more than 8.5E12cm-22DEG mobility of more than 1800cm2V.s, wherein the carrier gas H2/N2At 0.75, the 2DEG areal densities of the epitaxial wafer at the center position, the middle ring position and the edge position were 9.45E12cm-2、1.01E13cm-2And 8.69E12cm-2Near the theoretical value (1E13 cm)-2) 2DEG mobility of 1830cm each2/V·s、1850cm2V.s and 1920cm2/V·s。
Based on the carrier gas debugging method, the invention also carries out partition control transformation on the spray header of the MOCVD wafer reaction cavity, the gas outlet of the spray header is divided into a central area and an edge area, and each area is independently controlled, so that the uniformity of wafer growth is consistent from inside to outside.
Drawings
Fig. 1 to 8 show structural diagrams of steps of the method for manufacturing the silicon-based GaN-HEMT epitaxial structure of the present invention.
Fig. 9 is a schematic view of a wafer partition showing a method for fabricating a silicon-based GaN-HEMT epitaxial structure according to an embodiment of the present invention.
FIGS. 10 and 11 show different carrier gases H during the growth of AlGaN and GaN, respectively, according to embodiments of the present invention2/N2A plot of the growth rate of zone a versus zone B on a 6 inch wafer.
FIG. 12 shows a variation H of the present invention2/N2The ratio and the thickness uniformity of the GaN-HEMT epitaxial structure.
FIG. 13 shows a variation H of the present invention2/N2Ratio and thickness profile of the GaN-HEMT epitaxial structure.
FIG. 14 shows different H in carrier gas of organometallic source MO in accordance with an embodiment of the present invention2/N2The ratio and the aluminum composition uniformity of the AlGaN barrier layer.
FIGS. 15 and 16 show different carrier gases H in the organometallic source MO, respectively2/N2Ratio versus 2DEG areal density and mobility at wafer center, mid-circle and edge positions.
Description of the element reference numerals
101 silicon substrate
102 nucleation layer
103 buffer layer
104 carbon doped GaN high resistance layer
105 undoped GaN channel layer
106 AlN space layer
107 AlGaN barrier layer
108 GaN capping layer
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.
As in the detailed description of the embodiments of the present invention, the cross-sectional views illustrating the device structures are not partially enlarged in general scale for convenience of illustration, and the schematic views are only examples, which should not limit the scope of the present invention. In addition, the three-dimensional dimensions of length, width and depth should be included in the actual fabrication.
For convenience in description, spatial relational terms such as "below," "beneath," "below," "under," "over," "upper," and the like may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that these terms of spatial relationship are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the figures. Further, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present.
In the context of this application, a structure described as having a first feature "on" a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed in between the first and second features, such that the first and second features may not be in direct contact.
It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the drawings only show the components related to the present invention rather than being drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of each component in actual implementation may be changed arbitrarily, and the layout of the components may be more complicated.
The invention adopts H in the MOCVD system2And N2As a carrier gas, H2The atmosphere is favorable for the source metal atoms to move on the surface of the substrate. N is a radical of2The molecular weight is large, the diffusion capability of the V/III group reaction source can be enhanced, and the method is low in cost, safe and reliable. N is a radical of2The flow can affect the diffusion condition of the reaction source and can also affect the gas flow field in a certain range, so that H in the V/III group reaction source2/N2The carrier gas has a regulating effect on the epitaxial growth. The invention adjusts H in the epitaxial growth process of the AlGaN/GaN HEMT structure2/N2The carrier gas ratio improves the growth rate uniformity and thickness uniformity of different areas of a large-size wafer, the Al composition uniformity of the AlGaN barrier layer 107 and the surface density and mobility of 2DEG at different positions.
As shown in fig. 1 to 8, the present embodiment provides a method for manufacturing a silicon-based GaN-HEMT epitaxial structure, where the method includes:
as shown in FIG. 1, step 1) is first performed to provide a silicon substrate 101 at H2And carrying out heat treatment on the silicon substrate 101 in an atmosphere for 3-10 min to remove oxides on the surface of the silicon substrate 101. In this embodiment, the silicon substrate 101 is selected to be a 6-inch silicon substrate 101 with a crystal orientation (111).
As shown in fig. 2 to 8, step 2) is then performed, and a GaN-HEMT epitaxial structure is formed on the silicon substrate 101 by using a metal organic chemical vapor deposition process.
Specifically, the forming of the GaN-HEMT epitaxial structure comprises the following steps:
as shown in fig. 2, step 2-1) is performed, and a nucleation layer 102 is epitaxially grown on the silicon substrate 101 at 1165 ℃; in this embodiment, the nucleation layer 102 comprises an AlN nucleation layer 102.
As shown in fig. 3, performing step 2-2), epitaxially growing a buffer layer 103 on the nucleation layer 102 at 1085 ℃; in the present embodiment, the buffer layer 103 includes a plurality of AlGaN buffer layers 103, wherein the composition of Al in the plurality of AlGaN buffer layers 103 is gradually decreased.
As shown in fig. 4, step 2-3) is performed to epitaxially grow a carbon-doped GaN high-resistance layer 104 on the buffer layer 103.
As shown in fig. 5, performing step 2-4), epitaxially growing an undoped GaN channel layer 105 on the carbon-doped GaN high-resistance layer 104;
as shown in fig. 6, step 2-5) is performed to epitaxially grow an AlN space layer 106 on the undoped GaN channel layer;
as shown in fig. 7, step 2-6) is performed to epitaxially grow an AlGaN barrier layer 107 on the AlN space layer 106, where the AlGaN barrier layer 107 has an Al molar composition of 25% in the present embodiment;
as shown in fig. 8, step 2-7) is performed to epitaxially grow a GaN cap layer 108 on the AlGaN barrier layer 107; the GaN cap 108 is used to prevent the AlGaN barrier layer 107 from being oxidized.
In the steps 2-1) to 2-7), the gas source adopted by the epitaxial growth of the GaN-HEMT epitaxial structure comprises an organic metal source and a nitrogen source, and the organic metal source and the nitrogen source are both H2And N2As carrier gas, wherein the carrier gas H of the nitrogen source2And N2The volume ratio of (A) to (B) is 1.75-2.5, and the carrier gas H of the organic metal source2And N2The volume ratio of the GaN-HEMT epitaxial structure is 0.4-1, and the uniformity of the epitaxial growth thickness of the GaN-HEMT epitaxial structure is less than or equal to 1% through the carrier gas ratio. Further, when the carrier gas H of the nitrogen source is used2And N2The volume ratio of (a) is 2.2-2.3, so that the epitaxial growth thickness uniformity of the GaN-HEMT epitaxial structure is less than or equal to 0.5%.
In this embodiment, the thickness of the GaN-HEMT epitaxial structure is 4.0 μm to 4.5 μm, and in a specific implementation process, the thickness of the GaN-HEMT epitaxial structure is 4.2 μm.
In this embodiment, the epitaxial growth of the undoped GaN channel layer uses trimethylgallium as the gallium source, NH3As nitrogen source, H2And N2As carrier gas, wherein the carrier gas H of the nitrogen source2And N2Is 1.75 to 2.5, so that the growth rate uniformity of the undoped GaN channel layer is less than or equal to 1%.
In this embodiment, the AlGaN barrier layer 107 is epitaxially grown with trimethylgallium and trimethylaluminum as a gallium source and an aluminum source, respectively, NH3As nitrogen source, H2And N2As a carrier gas, wherein the carrier gas H of trimethyl gallium and trimethyl aluminum2And N2Is 0.4 to 1, so that the Al composition uniformity of the AlGaN barrier layer 107 is 1% or less.
In this embodiment, the AlGaN barrier layer 107 is epitaxially grown with trimethylgallium and trimethylaluminum as a gallium source and an aluminum source, respectively, NH3As nitrogen source, H2And N2As a carrier gas, wherein the carrier gas H of trimethyl gallium and trimethyl aluminum2And N2The volume ratio of (A) to (B) is 0.4-1, so that the 2DEG mobility of the GaN-HEMT epitaxial structure is larger than or equal to 1800cm2Has an areal density of 8.5E12cm or more-2. Further, the carrier gas H of trimethyl gallium and trimethyl aluminum2And N2The volume ratio of (A) to (B) is 0.7-0.8, and the 2DEG mobility of the GaN-HEMT epitaxial structure can be larger than 1900cm2/V·s。
In this embodiment, the showerhead used in the metal organic chemical vapor deposition process includes a middle region gas outlet and a rim gas outlet surrounding the middle region gas outlet, and the middle region gas outlet and the rim gas outlet are independently controlled.
As shown in FIGS. 9 to 11, the present embodiment adjusts the carrier gas H2/N2In contrast, the uniformity of growth rate in different regions can be adjusted. FIG. 9 is a schematic view of a wafer zone, and FIGS. 10 and 11 are schematic views of different carrier gases H during AlGaN and GaN growth, respectively2/N2The growth rate of the area A (radius r is 30 mm) and the growth rate of the area B (radius r is 60 mm) on a 6-inch wafer are plotted. Keeping the total flow of the group III organometallic source MO constant and the group V reaction source NH constant3And a carrier gas H2、N2The total flow is not changed, and the carrier gas H in the V group reaction source is adjusted2/N2Ratio, found when H2/N2When the growth rate is gradually increased, the growth rate of the region of the wafer area A is gradually decreased, and the growth rate of the region of the wafer area B is gradually increased. This is because the ammonia gas is introduced from the outlet at the edge of the shower head and diffuses from the outside to the inside as the carrier gas H2/N2When the ratio is gradually increased, N2The NH diffused toward the wafer center is reduced because the diffusion capability of the carrier gas is reduced3The decrease results in a decrease in the reaction rate in the middle of the wafer and an increase in the reaction rate at the edge. As can be seen from the results, NH occurred during the growth of AlGaN3Carrier gas H of2/N2The ratio of the carrier gas H to the carrier gas H is 1.5-2.25, the uniformity of the reaction rate of the A, B regions is less than 1%2/N2The growth rate uniformity is optimally 0.43% when the ratio of (1.75). Carrier gas H in GaN growth process2/N2When the ratio of (A) to (B) is 1.75 to 2.5, the uniformity of the reaction rate is 1% or less, wherein the carrier gas H2/N2When the ratio of (A) to (B) is 2.25, the uniformity is preferably 0.09%.
As shown in FIGS. 12 and 13, the present embodiment adjusts the carrier gas H2/N2The epitaxial layer thickness uniformity can be adjusted. The thickness uniformity of the epitaxial wafer is one of important indexes of the device, good crystal quality can be guaranteed through good thickness uniformity, and the yield and the reliability of the device are improved. FIG. 12 is a graph showing a difference H2/N2The ratio and the thickness uniformity of the GaN-HEMT epitaxial structure are in a relationship chart, the flow of the III group organic metal source MO is kept unchanged, and the V group reaction source NH is kept3、H2、N2The total flow is constant and NH is adjusted3Middle carrier gas H2/N2Ratio, finding NH3H of (A) to (B)2/N2When the ratio is 1.75-2.5, the thickness uniformity of the whole epitaxial layer can be below 1%, wherein H2/N2The best thickness uniformity was 0.44% at 2.25, and the thickness profile is shown in fig. 13. An optimum H for thickness uniformity can be found2/N2Optimum H ratio to GaN growth rate uniformity2/N2The ratio is the same becauseGood growth rate uniformity allows for the growth of a flat GaN layer, while a thicker GaN layer directly affects the thickness uniformity of the entire epitaxial layer.
As shown in FIG. 14, the present embodiment is implemented by adjusting the carrier gas H2/N2In contrast, the AlGaN barrier layer 107 can adjust the aluminum composition uniformity. The AlGaN barrier layer 107 is the most core part of the AlGaN/GaN HEMT structure, and the growth quality of the AlGaN barrier layer 107 directly determines the practicability of the device. The aluminum composition of the AlGaN barrier layer 107 affects the polarization electric field between AlGaN and GaN, and thus affects the two-dimensional electron gas surface density. Therefore, good aluminum composition uniformity on large-sized wafers is an important guarantee for HEMT devices. FIG. 14 shows different H in carrier gas of organometallic source MO2/N2The ratio and the uniformity of the aluminum composition of the AlGaN barrier layer 107 are plotted in a relationship of the ratio and the uniformity of the aluminum composition of the AlGaN barrier layer, and the group V reactant NH is maintained3Keeping the total flow of the group III organic metal source MO unchanged, and finding out carrier gas H in the organic metal source2/N2When the ratio is between 0.5 and 1, the Al composition uniformity of the AlGaN barrier layer 107 can be below 1%, wherein the carrier gas H2/N2When the composition is 0.75, the AlGaN barrier layer 107 has an optimum Al composition uniformity of 0.95% (Al content 25%). H in an organometallic source2/N2The carrier gas can regulate and control the distribution amount of TMAl on the whole wafer, thereby achieving the uniform distribution of Al components.
As shown in FIGS. 15 and 16, the present embodiment adjusts the carrier gas H2/N2The 2DEG areal density and mobility can be adjusted. FIGS. 15 and 16 show different carrier gases H in the organometallic source MO, respectively2/N2Ratio versus 2DEG areal density and mobility at the Center, Middle, and Edge positions Center, Middle, and Edge of the wafer. Maintaining a group V reactive source NH3Keeping the flow rate of the group III organic metal source MO constant, and finding that the carrier gas H in the organic metal source MO2/N2The 2DEG areal density at the center position, the middle ring position and the edge position is 8.5E12cm when the ratio is between 0.5 and 1-2The 2DEG mobility can be 1800cm 2/V.s or more, wherein when the carrier gas H2/N2 ratio is 0.75, the 2DEG areal density of the wafer at the center position, the center circle position and the edge position is 9.45E12cm-2、1.01E13cm-2And 8.69E12cm-2Near theoretical value (1E13 cm)-2) 2DEG mobility of 1830cm each2/V·s、1850cm2V.s and 1920cm2/V·s。
Further, the MOCVD single wafer reaction chamber can grow high-quality 6-inch and 8-inch epitaxial wafers with better uniformity and less surface defects, but the central epitaxial layer of the non-eccentric single wafer reaction chamber can grow thicker due to the fact that the linear speed is 0 during the rotation process of the central position of the wafer, and the uniformity of epitaxial growth is affected. Based on the above H2/N2The invention also relates to a method for regulating and controlling uniformity by carrier gas, which improves the zone control of a spray header of a single-wafer reaction cavity, and divides an air outlet of the spray header into a center area and an edge area to be independently controlled, thereby ensuring better growth quality in the center and better uniformity of the whole wafer. One of the advantages of this design is: the traditional integrally controlled spray head generally changes the ratio of the amount of a V-group material reaction source to the amount of a III-group material reaction source to adjust the uniformity, and slightly changes the carrier gas to have smaller influence on a system flow field and more controllable and stable growth compared with the change of the V/III ratio. Therefore, the invention designs the spray head controlled by regions and combines the method of regulating and controlling carrier gas, and can more stably and efficiently realize the uniform growth of large-size wafers.
As described above, the method for manufacturing the silicon-based GaN-HEMT epitaxial structure of the present invention has the following beneficial effects:
the invention adjusts H when the MOCVD epitaxy grows the GaN-HEMT epitaxy structure2/N2The carrier gas ratio improves the growth rate uniformity and the thickness uniformity of different areas, the Al component uniformity of the AlGaN barrier layer 107, the 2DEG surface density and the mobility of two-dimensional electron gas in the epitaxial growth process of the silicon-based AlGaN/GaN HEMT.
NH during GaN growth3Carrier gas H of2/N2When the ratio is between 1.75 and 2.5, the thickness uniformity of the whole epitaxial layer can be below 1%, wherein the carrier gas H2/N2At a ratio of 2.25, the thickness uniformity is optimally 0.44%.
Organometallic during growth of AlGaN barrier layer 107Carrier gas H of source2/N2When the ratio is between 0.5 and 1, the Al composition uniformity of the AlGaN barrier layer 107 can be below 1%, wherein the carrier gas H2/N2At a ratio of 0.75, the Al composition uniformity is optimally 0.99%.
Carrier gas H of organic metal source during growth of AlGaN barrier layer 1072/N2When the ratio is between 0.5 and 1, the 2DEG surface density of the epitaxial wafer at the center position, the middle ring position and the edge position is more than 8.5E12cm-22DEG mobility of more than 1800cm2V.s, wherein the carrier gas H2/N2At 0.75, the 2DEG areal densities of the epitaxial wafer at the center position, the middle ring position and the edge position were 9.45E12cm-2、1.01E13cm-2And 8.69E12cm-2Near theoretical value (1E13 cm)-2) 2DEG mobility of 1830cm each2/V·s、1850cm2V.s and 1920cm2/V·s。
Based on the carrier gas debugging method, the invention also carries out partition control transformation on the spray header of the MOCVD wafer reaction cavity, the gas outlet of the spray header is divided into a central area and an edge area, and each area is independently controlled, so that the uniformity of wafer growth is consistent from inside to outside.
Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.
The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims (10)

1. A manufacturing method of a silicon-based GaN-HEMT epitaxial structure is characterized by comprising the following steps:
providing a silicon substrate;
forming a GaN-HEMT epitaxial structure on the silicon substrate by adopting a metal organic chemical vapor deposition process, comprising the following steps of: epitaxially growing a nucleation layer on the silicon substrate; epitaxially growing a buffer layer on the nucleation layer; epitaxially growing a carbon-doped GaN high-resistance layer on the buffer layer; epitaxially growing a non-doped GaN channel layer on the carbon-doped GaN high-resistance layer; epitaxially growing an AlN spatial layer on the non-doped GaN channel layer; epitaxially growing an AlGaN barrier layer on the AlN space layer; epitaxially growing a GaN cap layer on the AlGaN barrier layer;
the gas source adopted by the epitaxial growth of the GaN-HEMT epitaxial structure comprises an organic metal source and a nitrogen source, wherein the organic metal source and the nitrogen source are both H2And N2As carrier gas, wherein the carrier gas H of the nitrogen source2And N2The volume ratio of (A) to (B) is 1.75-2.5, and the carrier gas H of the organic metal source2And N2The volume ratio of (A) to (B) is 0.4 to 1.
2. The method for manufacturing the epitaxial structure of the silicon-based GaN-HEMT according to claim 1, characterized in that: the epitaxial growth thickness uniformity of the GaN-HEMT epitaxial structure is less than or equal to 1%.
3. The method for manufacturing the epitaxial structure of the silicon-based GaN-HEMT according to claim 2, characterized in that: carrier gas H for the nitrogen source2And N2The volume ratio of (a) is 2.2-2.3, so that the epitaxial growth thickness uniformity of the GaN-HEMT epitaxial structure is less than or equal to 0.5%.
4. The method for manufacturing the epitaxial structure of the silicon-based GaN-HEMT according to claim 1, characterized in that: the epitaxial growth of the non-doped GaN channel layer takes trimethyl gallium as a gallium source and NH3As nitrogen source, H2And N2As carrier gas, wherein the carrier gas H of the nitrogen source2And N2Is 1.75 to 2.5, so that the growth rate uniformity of the undoped GaN channel layer is less than or equal to 1%.
5. The method for manufacturing the epitaxial structure of the silicon-based GaN-HEMT according to claim 1, characterized in that: the epitaxial growth of the AlGaN barrier layer takes trimethyl gallium and trimethyl aluminum as a gallium source and an aluminum source respectively, NH3As nitrogen source, H2And N2As a carrier gas, wherein the carrier gas H of trimethyl gallium and trimethyl aluminum2And N2Is 0.4 to 1, so that the Al component uniformity of the AlGaN barrier layer is less than or equal to 1%.
6. The method for manufacturing the epitaxial structure of the silicon-based GaN-HEMT according to claim 1, characterized in that: the epitaxial growth of the AlGaN barrier layer takes trimethyl gallium and trimethyl aluminum as a gallium source and an aluminum source respectively, NH3As nitrogen source, H2And N2As a carrier gas, wherein the carrier gas H of trimethyl gallium and trimethyl aluminum2And N2Is 0.4 to 1, so that the 2DEG mobility of the GaN-HEMT epitaxial structure is larger than or equal to 1800cm2Has an areal density of 8.5E12cm or more-2。
7. The method for manufacturing the epitaxial structure of the silicon-based GaN-HEMT according to claim 6, wherein the step of forming the epitaxial structure of the silicon-based GaN-HEMT comprises the following steps: carrier gas H of trimethyl gallium and trimethyl aluminum2And N2The volume ratio of (A) to (B) is 0.7-0.8, so that the 2DEG mobility of the GaN-HEMT epitaxial structure is larger than 1900cm2/V·s。
8. The method for manufacturing the epitaxial structure of the silicon-based GaN-HEMT according to claim 1, characterized in that: the spray header adopted by the metal organic chemical vapor deposition process comprises a middle area air outlet and an edge air outlet surrounding the middle area air outlet, wherein the middle area air outlet and the edge air outlet are independently controlled.
9. The method for manufacturing the epitaxial structure of the silicon-based GaN-HEMT according to claim 1, characterized in that: after providing a silicon substrate, the method also comprises2A step of heat-treating the silicon substrate under an atmosphereTo remove the oxide on the surface of the silicon substrate.
10. The method for manufacturing the epitaxial structure of the silicon-based GaN-HEMT according to claim 1, characterized in that: the nucleation layer comprises an AlN nucleation layer, and the buffer layer comprises a plurality of AlGaN buffer layers, wherein the Al component in the plurality of AlGaN buffer layers is gradually reduced.
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1075019A (en) * 1996-06-28 1998-03-17 Toshiba Corp Manufacture of gan compound semiconductor device
JPH11283925A (en) * 1998-03-26 1999-10-15 Univ Shizuoka Method for manufacturing compound semiconductor film
WO2000034990A1 (en) * 1998-12-07 2000-06-15 Deutsche Telekom Ag Production of multilayer semiconductor structures by changing the carrier gas
JP2004119405A (en) * 2002-09-20 2004-04-15 Sharp Corp PROCESS FOR GROWING GaNP CRYSTAL AND SEMICONDUCTOR DEVICE HAVING GaNP CRYSTAL
JP2007246341A (en) * 2006-03-16 2007-09-27 Toyoda Gosei Co Ltd Light element substrate, its manufacturing method, semiconductor light emitting element, and semiconductor light receiving element

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1075019A (en) * 1996-06-28 1998-03-17 Toshiba Corp Manufacture of gan compound semiconductor device
JPH11283925A (en) * 1998-03-26 1999-10-15 Univ Shizuoka Method for manufacturing compound semiconductor film
WO2000034990A1 (en) * 1998-12-07 2000-06-15 Deutsche Telekom Ag Production of multilayer semiconductor structures by changing the carrier gas
DE19856245A1 (en) * 1998-12-07 2000-06-15 Deutsche Telekom Ag Process for the production of multilayer semiconductor structures
JP2004119405A (en) * 2002-09-20 2004-04-15 Sharp Corp PROCESS FOR GROWING GaNP CRYSTAL AND SEMICONDUCTOR DEVICE HAVING GaNP CRYSTAL
JP2007246341A (en) * 2006-03-16 2007-09-27 Toyoda Gosei Co Ltd Light element substrate, its manufacturing method, semiconductor light emitting element, and semiconductor light receiving element

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