TWI770758B - High Electron Mobility Transistor with Reflective Structure - Google Patents

Abstract

The present invention provides a high electron mobility transistor with a reflective structure, which comprises a plurality of electrodes, a source electrode, a drain electrode and a gate electrode, which are respectively coupled above one of a first substrate, the first The semiconductor layer is coupled over one of the electrodes, the second semiconductor layer is coupled over one of the first semiconductor layers, the third semiconductor layer is coupled over one of the second semiconductor layers, and the buffer layer is coupled on one of the third semiconductor layers, the second substrate is disposed above one of the buffer layers, the reflective layer is disposed above one of the second substrates, and the flip-chip package is combined with the reflective layer structure, Further reduce the size of the communication chip.

Description

High Electron Mobility Transistor with Reflective Structure

The present invention relates to a high electron mobility transistor with a reflective structure, in particular to a flip-chip chip structure with a reflective layer.

With the development of the times, the technology of wireless transmission and wireless communication has been widely used in all walks of life, and has gradually replaced the traditional way of information dissemination, thus creating a new generation of electronic industry. In order to meet the needs of wireless transmission and communication, all kinds of electronic products have the function of wireless transmission, among which an integrated circuit (IC) with a wireless antenna is one of the indispensable components.

The traditional wireless antenna IC chip mainly includes an antenna and a microcircuit, and has an antenna in package (AIP) structure. By placing an IC chip in an electronic product, the wireless signal transmission operation can be performed with the receiving or transmitting end. , Therefore, the test of the wireless antenna IC chip is also a major part of the production cost.

The main goal of future wireless chip products is to design for a higher operating frequency range (GHz), such as 5G (5th generation mobile network or 5th generation wireless system). 5G communication is expected to be greater than or equal to 15GHz. The current WiGig (Wireless Gigabit Alliance) products operate at 60GHz, and other applications, including automotive radar and medical imaging, use wireless communication technology at millimeter wave frequencies (such as 30GHz-300GHz). High electron mobility transistors (HEMTs) using gallium nitride (GaN) are attracting attention.

Referring to FIG. 5, which is a schematic diagram of the structure of a conventional chip, as shown in the figure, the structure of a conventional high electron mobility transistor generally includes: a substrate, a buffer layer, each semiconductor layer containing gallium nitride, and a source electrode, a drain electrode and a drain electrode. pole and gate for external electrical connection.

Gallium nitride is a very stable compound and a hard high-melting material with a melting point of about 1700°C. Gallium nitride has a high degree of ionization, which is the highest (0.5 or 0.43) among III-V compounds. At atmospheric pressure, gallium nitride crystals generally have a hexagonal wurtzite structure.

Gallium nitride technology dates back to the 1970s, when Radio Corporation of America (RCA) developed a gallium nitride process to manufacture light-emitting diodes (LEDs). It has become the mainstream of light-emitting diodes, and many light-emitting diodes on the market now use gallium nitride technology on sapphire substrates.

As the manufacturing cost of gallium nitride semiconductors decreases, there is huge room for market growth. Gallium nitride and silicon carbide (SiC) and silicon (Si) materials have their own advantages in areas; With the decline in cost, gallium nitride is expected to replace silicon-based power components such as diodes, IGBTs, and MOSFETs in low- and medium-power fields. According to voltage, 0~300V is dominated by silicon materials, and above 600V is dominated by silicon carbide. , 300V~600V is the dominant field of gallium nitride materials.

5G will bring revolutionary changes in semiconductor materials. With the migration of communication frequency bands to high frequencies, base stations and communication equipment need radio frequency devices that support high frequency performance. The advantages of gallium nitride will gradually become prominent, which is exactly what was discussed in the previous section. . It is this advantage that makes gallium nitride a key technology for transistors in the high operating frequency range.

Compared with the 3G and 4G eras, the number of radio frequency devices in the 5G era will increase by dozens or even hundreds of times. In 5G millimeter wave applications, the high power density characteristics of gallium nitride are being realized Under the same coverage conditions and user tracking function, the number of transceiver channels and the overall solution size can be effectively reduced.

However, for the above-mentioned wireless communication chip, the current design usually uses a DIP package (dual in-line package), which increases the volume of the communication chip, making it difficult to further reduce the volume and thickness of products using the package chip. It is known that the wireless communication chip also has a reduced life due to the external ambient light (the casing of the communication chip is usually thin). Therefore, the industry needs a package structure that can reduce the volume of the wireless communication chip and increase its use time. .

In view of the above-mentioned problems of the prior art, the present invention provides a high electron mobility transistor with a reflective structure, wherein a plurality of electrodes are coupled to a substrate with connectors, and are arranged above the substrate, and the reflective layer is used. Reflecting external light to protect the underlying semiconductor layer, this structure further reduces the thickness of the chip.

An object of the present invention is to provide a high electron mobility transistor with a reflective structure, wherein a plurality of electrodes are respectively coupled above a substrate by a connector, and a reflective layer is disposed above each semiconductor layer, so as to Reflecting external light and protecting the semiconductor layers below, this structure further reduces the thickness of the chip and increases the overall life of the chip.

In order to achieve the above-mentioned objects and effects, the present invention provides a high electron mobility transistor with a reflective structure, comprising: a first substrate, a plurality of electrodes, a first semiconductor layer, a second semiconductor layer, A third semiconductor layer, a buffer layer, a second substrate and a reflective layer, a plurality of lines are arranged on one of the first substrates, the electrodes include a source electrode, a drain electrode and a gate electrode, the source electrode The electrode, the drain electrode and the gate electrode are respectively coupled over one of the lines, the first semiconductor layer is coupled over one of the electrodes, the The second semiconductor layer is coupled over one of the first semiconductor layers, the third semiconductor layer is coupled over one of the second semiconductor layers, the buffer layer is coupled over one of the third semiconductor layers, and the third semiconductor layer is coupled over one of the second semiconductor layers. Two substrates are arranged above one of the buffer layers, and the reflective layer is arranged above one of the second substrates; the structure of the flip chip package and the reflective layer is used to further reduce the volume of the communication chip.

In an embodiment of the present invention, a connecting member is respectively disposed between the source electrode, the drain electrode and the gate electrode and the first substrate.

In an embodiment of the present invention, the connecting member is a solder ball or a metal bump.

In one embodiment of the present invention, the material of the first semiconductor layer and the material of the third semiconductor layer are intrinsic gallium nitride.

In one embodiment of the present invention, the material of the second semiconductor layer is intrinsic aluminum gallium nitride.

In an embodiment of the present invention, the material of the first substrate comprises aluminum nitride.

In an embodiment of the present invention, the material of the second substrate includes silicon.

In one embodiment of the present invention, the material of the reflective layer is metal.

In an embodiment of the present invention, the reflective layer is coupled to a ground terminal of the first substrate.

1: The first substrate

2: High electron mobility transistor with reflective structure

3: Ground terminal

10: Electrodes

12: Source

12': source

14: Drain

14': Drain

16: Gate

16': Gate

20: The first semiconductor layer

30: Second semiconductor layer

40: The third semiconductor layer

50: Buffer layer

60: Second substrate

70: Reflective layer

80: Connector

90: Line

L: External light

Figure 1: It is a schematic view of the structure of the embodiment of the present invention; Figure 2: It is a schematic view of the light reflection of the embodiment of the present invention; Figure 3: It is a schematic view of the structure of the first substrate of the embodiment of the present invention. Figure: it is a structural schematic diagram of a connector according to an embodiment of the present invention; and FIG. 5 is a schematic diagram of a conventional chip structure.

In order to make your examiners have a further understanding and understanding of the features of the present invention and the effects achieved, the following examples are provided and the descriptions are as follows: In view of the above-mentioned problems of the prior art, the present invention provides a plurality of The electrodes are respectively coupled on one of the first substrates by connecting pieces, and a chip structure is arranged above one of the plurality of semiconductor layers by using a reflective layer, and the reflective layer is used to reflect external light to protect the lower ones. The semiconductor layer, with this structure, further reduces the thickness of the chip and increases the lifespan of the entire chip, solving the problems that the conventional technology is difficult to reduce the thickness of the chip and has a short lifespan.

Please refer to FIG. 1 , which is a schematic structural diagram of an embodiment of the present invention. As shown in the figure, the embodiment is a high electron mobility transistor 2 with a reflective structure, which is disposed above a first substrate 1 , the high electron mobility transistor 2 with a reflective structure includes a plurality of electrodes 10, a first semiconductor layer 20, a second semiconductor layer 30, a third semiconductor layer 40, a buffer layer 50, and a second substrate 60 and a reflective layer 70, which are stacked on each other to form a transistor structure; in this embodiment, the material of the first substrate 1 includes aluminum nitride (AlN).

Referring to FIG. 1 and FIG. 2 again, FIG. 2 is a schematic diagram of light reflection according to an embodiment of the present invention. As shown in the figure, in this embodiment, the electrodes 10 include a source electrode 12 (source), A drain electrode 14 (drain) and a gate electrode 16 (gate), the source electrode 12 , the drain electrode 14 and the gate electrode 16 are respectively coupled to the top of the first substrate 1 , the first semiconductor layer 20 is coupled over one of the electrodes 10 , that is, the first semiconductor layer 20 is coupled over one of the source electrode 12 , the drain electrode 14 and the gate electrode 16 , and the second semiconductor layer 30 is coupled to the Above one of the first semiconductor layers 20 , the third semiconductor layer 40 is coupled to one of the second semiconductor layers 30 Above, the buffer layer 50 is coupled over one of the third semiconductor layers 40 , the second substrate 60 is disposed over one of the buffer layers 50 , and the reflective layer 70 is disposed over one of the second substrates 60 On the top, the structures stacked on each other form a high electron mobility transistor (HEMT).

Continuing the above, as shown in the figure, in this embodiment, the material of the first semiconductor layer 20 and the material of the third semiconductor layer 40 are intrinsic gallium nitride (i-GaN), and the material of the second semiconductor layer 30 is intrinsic gallium nitride (i-GaN). The material is intrinsic aluminum gallium nitride (i-AlGaN), the material of the second substrate 60 includes silicon (Si), and the material of the reflective layer 70 is metal, such as silver (Ag), to reflect an external light L, to prevent the electrodes 10 , the first semiconductor layer 20 , the second semiconductor layer 30 , the third semiconductor layer 40 , the buffer layer 50 and the second substrate 60 from being irradiated by the external light L, thereby reducing usage life.

Continuing from the above, High electron mobility transistor (HEMT), or Modulation-doped FET (MODFET) is a type of field effect transistor that uses two different The material of the energy gap forms a heterojunction to provide a channel for the carriers, unlike the metal oxide semiconductor field effect transistor, which directly uses a doped semiconductor instead of a junction to form a conductive channel; among them, gallium arsenide (GaAs), Arsenic gallium aluminum ternary compound semiconductor is an optional material for forming this device. Of course, according to the specific application, there can be other combinations. For example, devices containing indium (In) generally show better high-frequency performance, while Gallium Nitride (GaN) High Electron Mobility Transistors (GaN), which can operate at very high frequencies, offer good high-frequency characteristics, making them widely used in mobile phones, satellite TV, and radar.

Referring to FIG. 1 and FIG. 2 again, as shown in the figures, in this embodiment, a plurality of lines 90 are disposed on one of the first substrates 1 , and the lines 90 are respectively coupled to the source electrodes 12 , The drain electrode 14 and the gate electrode 16 are used to transmit signals, and further the source electrode 12, the A connecting member 80 is disposed between the drain electrode 14 and the gate electrode 16 and the first substrate 1 respectively, wherein the respective connecting member 80 is a solder ball or a metal bump, and the connecting member 80 is the reflective structure. The high electron mobility transistor 2 is connected to the element of the first substrate 1 .

Referring to FIG. 1, FIG. 2 and FIG. 3 again, FIG. 3 is a schematic diagram of the structure of the first substrate according to the embodiment of the present invention. As shown in the figure, in this embodiment, the first substrate 1 is provided with these A circuit 90 includes a source electrode 12 ′, a drain electrode 14 ′, a gate electrode 16 ′ and a ground terminal 3 . The source electrode 12 ′, the drain electrode 14 ′ and the gate electrode 16 ′ are coupled by the connecting member 80 Connected to the source electrode 12 , the drain electrode 14 and the gate electrode 16 , the reflective layer 70 is coupled to the ground terminal 3 to prevent damage to the chip due to leakage.

Referring again to Fig. 1, Fig. 2, Fig. 3 and Fig. 4, Fig. 4 is a schematic diagram of the structure of the connecting member according to the embodiment of the present invention. As shown in the figure, in this embodiment, the connecting member 80 can be used Solder balls or metal bumps are used to couple and connect the source electrode 12 ′, the drain electrode 14 ′ and the gate electrode 16 ′ to the source electrode 12 , the drain electrode 14 and the gate electrode 16 .

In a high electron mobility transistor 2 with a reflective structure in this embodiment, the source electrode 12 , the drain electrode 14 and the gate electrode 16 are respectively coupled to the top of the first substrate 1 . The first semiconductor The layer 20 is coupled over the electrodes 10, the second semiconductor layer 30 is coupled over the first semiconductor layer 20, and the third semiconductor layer 40 is coupled over the second semiconductor layer 30, using The first semiconductor layer 20 and the third semiconductor layer 40 generate a two-dimensional electron gas, thereby generating a three-dimensional potential energy well, and the second semiconductor layer 30 can confine the electron gas in its electron channel, and the buffer layer 50 is coupled to Above the third semiconductor layer 40 , for preventing electron movement and preventing leakage, the second substrate 60 is disposed above the buffer layer 50 to provide heat dissipation and overall component support, and the reflective layer 70 is disposed on the second substrate 60 The upper part is used to reflect the external light L. In this embodiment, the structure combined with the reflective layer is used to further reduce the volume of the communication chip and reduce external interference.

To sum up, the present invention provides a high electron mobility transistor with a reflective structure, which utilizes a plurality of electrodes to be respectively coupled to one of the substrates by connecting elements, and utilizes a reflective light reflective layer disposed on the plurality of substrates. The chip structure above the semiconductor layer uses the reflective layer to reflect external light and protects the semiconductor layers below. This structure further reduces the thickness of the chip and increases the overall life of the chip, so as to solve the difficulty in the thickness of the chip in the prior art. reduction, and the problem of shorter service life.

Therefore, the present invention is indeed novel, progressive and available for industrial use, and it should meet the requirements for patent application in my country's patent law.

However, the above is only an embodiment of the present invention, and is not intended to limit the scope of the present invention. Therefore, all the equivalent changes and modifications made in accordance with the shape, structure, feature and spirit described in the scope of the patent application of the present invention, All should be included in the scope of the patent application of the present invention.

1: The first substrate

2: High electron mobility transistor with reflective structure

10: Electrodes

12: Source

14: Drain

16: Gate

20: The first semiconductor layer

30: Second semiconductor layer

40: The third semiconductor layer

50: Buffer layer

60: Second substrate

70: Reflective layer

80: Connector

90: Line

Claims (7)

A high electron mobility transistor with a reflective structure, comprising: a first substrate on which a plurality of lines are arranged; a plurality of electrodes including a source electrode, a drain electrode and a gate electrode, the source electrode, The drain electrode and the gate electrode are respectively coupled over one of the lines; a first semiconductor layer is coupled over one of the electrodes, and the material of the first semiconductor layer is intrinsically nitrided Gallium; a second semiconductor layer coupled over one of the first semiconductor layers; a third semiconductor layer coupled over one of the second semiconductor layers, the material of the third semiconductor layer being intrinsic nitrogen Gallium oxide; a buffer layer coupled over one of the third semiconductor layers; a second substrate disposed over one of the buffer layers; and a reflective layer disposed over one of the second substrates, The reflection layer is coupled to a ground terminal of the first substrate. The high electron mobility transistor with a reflective structure as claimed in claim 1, wherein a connecting member is respectively provided between the source electrode, the drain electrode and the gate electrode and the first substrate. The high electron mobility transistor with a reflective structure as claimed in claim 2, wherein the connecting element is a solder ball or a metal bump. The high electron mobility transistor with a reflective structure as claimed in claim 1, wherein the material of the second semiconductor layer is intrinsic aluminum gallium nitride. The high electron mobility transistor with a reflective structure as claimed in claim 1, wherein the material of the first substrate comprises aluminum nitride. The high electron mobility transistor with a reflective structure as claimed in claim 1, wherein the material of the second substrate comprises silicon. The high electron mobility transistor with a reflective structure as claimed in claim 1, wherein the material of the reflective layer is metal.

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