Novel GaN common-source amplifier and groove etching preparation method thereof

Abstract

The present invention provides a novel groove etching preparation method for a GaN common source amplifier, the preparation method comprising: growing an epitaxial structure on an n-type highly doped self-supporting GaN substrate, the epitaxial structure comprising a GaN buffer layer and an AlGaN buffer layer; sequentially plating a source electrode and two drain electrodes on the surface of the epitaxial structure; performing groove etching between the two drain electrodes; plating a gate electrode on the surface of the epitaxial structure to form a novel GaN common source amplifier, wherein the gate electrode is located between the source electrode and the drain electrode. The present invention also provides a novel GaN common source amplifier. The preparation method performs groove etching between the two drain electrodes, thereby reducing the movement of carriers therein and increasing the resistance of this part of the area, without the need for external resistance, reducing the production process, and increasing the service life of the product.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical communication, and in particular relates to a novel GaN common-source amplifier and a groove etching preparation method thereof. Background Art

[0002] The amplifier circuit is composed of a transistor (or field effect transistor), a capacitor, a resistor and a power supply. The amplifier circuit enhances the weak electrical signal to the required voltage, current or power value through electrical energy conversion, that is, it uses the amplification and control function of the transistor (or field effect transistor) to convert the energy of the power supply into an output that varies proportionally with the input.

[0003] Common-source amplifiers, also known as common-source amplifiers, together with common gate and common drain form a field-effect transistor (FET) amplifier circuit. They are the basic components of amplifier circuits. Common-source amplifiers are usually used as power amplifiers. Figure 1 As shown, in the field effect transistor amplifier circuit, the common gate is used as the input terminal (G), the common drain is used as the output terminal (D), and the common source (S) is used as the common terminal (for NMOS tubes, it is usually grounded). For AC signals, the common source is the common terminal, so the above circuit is usually called a common source amplifier circuit.

[0004] Existing common-source amplifiers often adjust the gain of the amplifier by adding external resistors, which not only increases the production process, but the loss of the external resistors during use may cause the amplification performance to be unstable and reduce the service life of the product. Summary of the invention

[0005] The embodiment of the present invention provides a novel GaN common-source amplifier and a groove etching preparation method thereof, aiming to solve the problem that the existing preparation method has complex preparation process and the loss of the external resistor during use leads to unstable amplification performance.

[0006] The embodiment of the present invention is implemented as follows: a novel groove etching preparation method for a GaN common source amplifier, the method comprising the following steps:

[0007] Growing an epitaxial structure on an n-type highly doped self-supporting GaN substrate, wherein the epitaxial structure includes a GaN buffer layer and an AlGaN buffer layer;

[0008] Sequentially plating a source electrode and two drain electrodes on the surface of the epitaxial structure;

[0009] Performing groove etching between the two drain electrodes;

[0010] A gate is plated on the surface of the epitaxial structure to form the novel GaN common-source amplifier, wherein the gate is located between the source and the drain.

[0011] Furthermore, before the step of sequentially plating a source electrode and two drain electrodes on the surface of the epitaxial structure, the method further comprises:

[0012] The AlGaN barrier layer and the n - The GaN layer is etched in an etching manner to form a pillar structure on the GaN.

[0013] Furthermore, after the step of performing a groove etching between the two drain electrodes, the method further includes:

[0014] Plasma treatment is performed on the groove formed by the groove etching.

[0015] Furthermore, the step of sequentially plating a source electrode and two drain electrodes on the surface of the epitaxial structure includes:

[0016] A first metal film is deposited on the surface of the AlGaN barrier layer of the GaN epitaxial structure to produce the source and the two drains, and high-temperature rapid annealing is performed to form ohmic contacts between the source and drain electrodes and the AlGaN barrier layer. The metal film is any one of Ti / Al / Ni / Au and Ti / Al / Pt / Au.

[0017] Furthermore, the step of plating a gate on the surface of the epitaxial structure includes:

[0018] The gate is manufactured by depositing a second metal film on the surface of the AlGaN barrier layer of the GaN epitaxial structure, wherein the second metal film is any one of Ni / Au and Ti / Au.

[0019] Furthermore, the step of growing a GaN epitaxial structure on an n-type highly doped self-supporting GaN substrate comprises:

[0020] The n-type highly doped GaN self-supporting substrate is sequentially grown by organic chemical vapor deposition. + Type GaN and n - Type GaN;

[0021] A layer of AlGaN barrier layer is deposited on the surface of the GaN substrate by using a plasma enhanced chemical vapor deposition method or an atomic layer deposition method.

[0022] Furthermore, the n + The thickness of GaN is 1 to 4 μm, and the carrier concentration is 5x10 17 ~3x10 18 cm -3; said n - The thickness of the GaN is 15 to 30 μm, and the carrier concentration is 4x10 15 ~1x10 16 cm -3 ; The thickness of the AlGaN barrier layer is 15 to 35 nm.

[0023] Furthermore, the n + The thickness of GaN is 1.5 to 3 μm, and the carrier concentration is 1x10 18 ~2x10 18 cm -3 ; said n - The thickness of the GaN is 20-25 μm, and the carrier concentration is 6x10 15 ~9x10 15 cm -3 ; The thickness of the AlGaN barrier layer is 20 to 30 nm.

[0024] Furthermore, the n + The thickness of the GaN is 2μm and the carrier concentration is 1.5x10 18 cm -3 ; said n - The thickness of the GaN is 23 μm and the carrier concentration is 8x10 15 cm -3 ; The thickness of the AlGaN barrier layer is 25 nm. In addition, the present application also provides a novel GaN common source amplifier. The novel GaN common source amplifier is prepared by any of the above-mentioned preparation methods.

[0025] The groove etching preparation method of the novel GaN common source amplifier in the present invention first grows an n-type highly doped self-supporting GaN substrate into a GaN epitaxial structure, then sequentially plates a source electrode and two drain electrodes on the grown GaN epitaxial structure, and performs groove etching between the two drain electrodes, and finally plates a gate electrode between the source electrode and the drain electrode to form a novel GaN common source amplifier. The preparation method performs groove etching between the two drain electrodes, thereby reducing the movement of carriers therein and increasing the resistance of this part of the area, without the need for external resistance, reducing the production process, and increasing the service life of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of a field effect transistor amplifier circuit;

[0027] Figure 2 It is a flow chart of a groove etching preparation method of a novel GaN common source amplifier provided by an embodiment of the present invention;

[0028] Figure 3is a schematic diagram of the GaNGaN buffer layer structure in an embodiment of the present invention;

[0029] Figure 4 It is another flow chart of the method for preparing the novel GaN common-source amplifier provided in an embodiment of the present invention.

[0030] Figure 5 1 is a schematic diagram of the structure of the preparation process of the novel GaN common-source amplifier in an embodiment of the present invention; DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0032] Embodiment 1

[0033] like Figure 2 As shown, an embodiment of the present invention provides a novel GaN common source amplifier manufacturing method. The novel GaN common source amplifier manufacturing method comprises the following steps:

[0034] Step S10, growing an n-type highly doped self-supporting GaN substrate into an epitaxial structure, wherein the epitaxial structure includes a GaN buffer layer and an AlGaN buffer layer;

[0035] The dopant of the n-type highly doped self-supporting GaN substrate can use hydrogen silane as the Si raw material, and the specific growth method can be the following steps:

[0036] 1. First, prepare a double-sided polished n-type highly doped free-standing GaN substrate.

[0037] 2. Use metal organic chemical vapor deposition (MOCVD) to grow n + Type GaN and n - Type GaN.

[0038] 3. Deposit an AlGaN barrier layer on the surface of the GaN-based device structure using plasma enhanced chemical vapor deposition (PECVD) or atomic layer deposition (ALD). Figure 3 The GaN epitaxial structure shown.

[0039] Among them, the n + The thickness of GaN is 1 to 4 μm, and the carrier concentration is 5x10 17 ~3x10 18 cm -3 ; said n - The thickness of the GaN is 15 to 30 μm, and the carrier concentration is 4x10 15 ~1x1016 cm -3 ; The thickness of the AlGaN barrier layer is 15 to 35 nm.

[0040] Furthermore, the n + The thickness of GaN is 1.5 to 3 μm, and the carrier concentration is 1x10 18 ~2x10 18 cm -3 ; said n - The thickness of the GaN is 20-25 μm, and the carrier concentration is 6x10 15 ~9x10 15 cm -3 ; The thickness of the AlGaN barrier layer is 20 to 30 nm.

[0041] Preferably, the n + The thickness of the GaN is 2μm and the carrier concentration is 1.5x10 18 cm -3 ; said n - The thickness of the GaN is 23 μm and the carrier concentration is 8x10 15 cm -3 ; The thickness of the AlGaN barrier layer is 25nm.

[0042] In addition, gallium nitride (GaN) is an important third-generation semiconductor material. It has excellent properties such as large bandgap, high breakdown electric field, large thermal conductivity, high electron saturation drift rate, and strong radiation resistance. It is used in the fields of solid-state light sources, power electronics, microwave radio frequency devices, etc. Existing common-source amplifiers are mostly made of silicon. Compared with silicon, gallium nitride has a larger bandgap and is more suitable for high-power components.

[0043] Step S20, sequentially plating a source electrode and two drain electrodes on the upper surface of the GaN epitaxial structure;

[0044] By photolithography adding a partial barrier layer on the surface of the AlGaN barrier layer of the GaN epitaxial structure, and then coating the metal film with a hot vapor coating machine as the source (S) and drain (D and V) of the device DD ), and form ohmic contacts between the electrodes (source and drain) and the AlGaN barrier layer by high temperature rapid annealing (RTA) at 800°C.

[0045] The metal film used for the source and drain can be Ti / Al / Ni / Au or Ti / Al / Pt / Au.

[0046] Step S30, performing groove etching between the two drain electrodes.

[0047] The groove etching method can be any of the following:

[0048] First, a barrier layer is formed between two drains (D and Vdd) using photoresist, and then ICP is used for etching, with the etching gas being Cl2 or Cl2 / CF4 mixed gas;

[0049] Secondly, a barrier layer is formed between two drains (D and Vdd) using photoresist, and then RIE is used for etching, with the etching gas being Cl2 or Cl2 / CF4 mixed gas.

[0050] Furthermore, the etched grooves are treated with O2 plasma to reduce the damage caused by etching and maintain the physical and chemical properties of the GaN epitaxial structure.

[0051] A groove is etched between the two drain electrodes by groove etching, and a groove is formed in the GaN epitaxial structure, thereby reducing the movement of carriers therein and increasing the resistance of this area, thereby achieving voltage amplification.

[0052] Step S40, plating a gate on the surface of the epitaxial structure to form the novel GaN common-source amplifier, wherein the gate is located between the source and the drain.

[0053] The formation of the gate is similar to that of the source and drain. The barrier layer is made using a photolithography process, and then a metal film is plated on the surface of the AlGaN barrier layer of the GaN epitaxial structure using a metal hot vapor coating machine as the gate of the device. The metal film used for the gate can be Ni / Au or Ti / Au, and the gate is located between the source and the drain.

[0054] The groove etching preparation method of the novel GaN common source amplifier in the present invention first grows an n-type highly doped self-supporting GaN substrate into a GaN epitaxial structure, then sequentially plates a source electrode and two drain electrodes on the grown GaN epitaxial structure, and performs groove etching between the two drain electrodes, and finally plates a gate electrode between the source electrode and the drain electrode to form a novel GaN common source amplifier. DD ) to reduce the movement of carriers therein and increase the resistance of this area. No external resistor is required, which reduces the production process and increases the service life of the product.

[0055] Embodiment 2

[0056] like Figure 4 As shown, an embodiment of the present invention provides a novel GaN common source amplifier preparation method. Based on the previous embodiment, before step S20, the novel GaN common source amplifier preparation method further includes the following steps:

[0057] Step S50, AlGaN barrier layer and n- The GaN layer is etched by dry etching to form a pillar structure on the GaN epitaxial structure.

[0058] A partial barrier layer is added on the surface of the AlGaN barrier layer of the GaN epitaxial structure by photolithography, and then both sides of the unblocked device are etched away by etching, thereby separating the AlGaN barrier layer and the n - The GaN layer is etched into a pillar structure by etching, and the pillar structure is used to prevent the current from being conducted on the substrate and affecting the device performance. The etching equipment is ICP or RIE, the gas used for etching is Cl2 or Cl2 / CF4 mixed gas, and the etching height is 70-90nm, preferably 80nm.

[0059] After forming a pillar structure on the GaN epitaxial structure, a source (S) and a drain (D and V) are sequentially plated on the upper surface of the pillar. DD ) and at both drains (D and V DD ) to etch a groove, and finally, plate a gate (G) between the source (S) and the drain (D) to form the novel GaN common-source amplifier. By etching a groove between the two drains, the movement of carriers therein is reduced, and the resistance of this area is increased, thereby achieving voltage amplification.

[0060] The structural schematic diagram of the novel GaN common source amplifier in the novel GaN common source amplifier preparation method of the present invention is as follows Figure 5 shown.

[0061] 1. Use organic chemical vapor deposition (MOCVD) to grow n-type highly doped self-supporting GaN substrate + Type GaN and n - Then, a layer of AlGaN barrier layer is deposited on the surface of the GaN-based device structure by plasma enhanced chemical vapor deposition (PECVD) or atomic layer deposition (ALD) to form a GaN epitaxial structure.

[0062] 2. AlGaN barrier layer and n - The type GaN layer is etched into a pillar structure by etching;

[0063] 3. Sequentially plate a source electrode and two drain electrodes on the upper surface of the column. Add a partial barrier layer by photolithography on the surface of the AlGaN barrier layer of the GaN epitaxial structure, and then use a hot vapor coating machine to coat a metal film as the source (S) and drain (D and V) of the device. DD ), and forming an ohmic contact between the electrode (source and drain) and the AlGaN barrier layer by high temperature rapid annealing at 800°C;

[0064] 4. At the two drains (D and V DD) are used to perform groove etching, and the groove etching method is the same as that described in the first embodiment;

[0065] 5. Use photolithography to make a barrier layer, and then use a hot vapor coating machine to coat a metal film on the surface of the AlGaN barrier layer of the GaN epitaxial structure (between the source S and the drain D) as the gate (G) of the device to form a new GaN common source amplifier.

[0066] In this embodiment, before the step of sequentially plating a source electrode and two drain electrodes on the GaN upper surface, the AlGaN barrier layer and the n - The GaN layer is etched to form a pillar structure on the GaN. A source electrode and two drain electrodes are plated on the surface of the pillar in sequence. The pillar structure is used to prevent current from being conducted on the substrate and affecting device performance.

[0067] In addition, the groove etching preparation method of the novel GaN common source amplifier of the present invention is also applicable to the preparation of an amplifier with SiC as a substrate.

[0068] Furthermore, the present invention also provides a novel GaN common-source amplifier, which is prepared by the preparation method of the above embodiment.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a GaN common source amplifier by groove etching, characterized in that: The preparation method of the common source amplifier comprises the following steps: Growing an epitaxial structure on an n-type highly doped self-supporting GaN substrate, wherein the epitaxial structure includes a GaN buffer layer and an AlGaN barrier layer; A source electrode, a drain electrode and a V electrode are sequentially plated on the surface of the epitaxial structure. dd pole; At the drain and V dd A groove is etched between the electrodes to form a groove in the GaN epitaxial structure, thereby reducing the movement of carriers and increasing the resistance of this area, thereby amplifying the voltage. A gate is plated on the surface of the epitaxial structure to form the GaN common-source amplifier, wherein the gate is located between the source and the drain.

2. The method for preparing a GaN common source amplifier by groove etching according to claim 1, characterized in that: A source electrode, a drain electrode and a V dd Before the extreme steps, it also includes: The GaN buffer layer comprises n + Type GaN and n - type GaN, the AlGaN barrier layer and n - The GaN layer is etched in an etching manner to form a pillar structure on the GaN epitaxial structure.

3. The method for preparing a GaN common source amplifier by groove etching according to claim 1, characterized in that: The drain and V dd After the step of etching grooves between the electrodes, the method further comprises: Plasma treatment is performed on the groove formed by the groove etching.

4. The method for preparing a GaN common source amplifier by groove etching according to claim 1, characterized in that: A source electrode, a drain electrode and a V dd The steps include: A first metal film is deposited on the surface of the AlGaN barrier layer of the GaN epitaxial structure to form the source electrode, the drain electrode and the V dd The source and drain are formed by high temperature rapid annealing. dd The pole electrode is in ohmic contact with the AlGaN barrier layer, and the metal film is any one of Ti / Al / Ni / Au and Ti / Al / Pt / Au.

5. The method for preparing a GaN common source amplifier by groove etching according to claim 1, characterized in that: The step of plating a gate on the surface of the epitaxial structure comprises: The gate is manufactured by depositing a second metal film on the surface of the AlGaN barrier layer of the GaN epitaxial structure, wherein the second metal film is any one of Ni / Au and Ti / Au.

6. The method for preparing a GaN common source amplifier by groove etching according to any one of claims 1 to 5, characterized in that: The step of growing an epitaxial structure on an n-type highly doped self-supporting GaN substrate comprises: The n-type highly doped GaN self-supporting substrate is sequentially grown by organic chemical vapor deposition. + Type GaN and n - Type GaN; Using plasma enhanced chemical vapor deposition method or atomic layer deposition method in the n - An AlGaN barrier layer is deposited on the surface of the GaN type.

7. The method for preparing a GaN common source amplifier by groove etching according to claim 6, characterized in that: The + The thickness of GaN is 1~4μm and the carrier concentration is 5 x10 17 ~3x10 18 cm -3 ; said n - The thickness of the GaN is 15~30μm and the carrier concentration is 4 x10 15 ~1x10 16 cm -3 ; The thickness of the AlGaN barrier layer is 15~35nm.

8. The method for preparing a GaN common source amplifier by groove etching according to claim 7, characterized in that: The + The thickness of GaN is 1.5~3μm, and the carrier concentration is 1x10 18 ~2x10 18 cm -3 ; said n - The thickness of GaN is 20~25μm and the carrier concentration is 6x10 15 ~9x10 15 cm -3 ; The thickness of the AlGaN barrier layer is 20~30nm.

9. The method for preparing a GaN common source amplifier by groove etching according to claim 8, characterized in that: The + The thickness of the GaN is 2μm and the carrier concentration is 1.5x10 18 cm -3 ; said n - The thickness of the GaN is 23 μm and the carrier concentration is 8x10 15 cm -3 ; The thickness of the AlGaN barrier layer is 25nm.

10. A GaN common source amplifier, characterized in that: The GaN common-source amplifier is prepared by any preparation method described in claims 1-9.

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