Charge compensation type Schottky diode resistant to high reverse bias voltage

Abstract

The invention discloses a high reverse bias resistant charge compensation type Schottky diode, which comprises a semi-insulating GaAs substrate, a GaAs buffer layer, a GaAs ohmic contact layer, a GaAs electric field collection layer, a GaAs charge compensation layer, a GaAs Schottky contact layer and a SiO2 passivation layer which are sequentially formed from bottom to top, and a cathode electrode formed on the ohmic contact layer and an anode electrode formed on the Schottky contact layer. A 10nm p-type charge compensation layer is introduced into an n-type GaAs epitaxial layer, the electric field distribution in the device is adjusted, most of the electric field is moved into an electric field collection region, and meanwhile, the width of a depletion region in the device is increased and the electric field intensity is weakened by reducing the doping concentration of the electric field collection region, so that the Schottky diode can bear higher bias voltage. The terahertz frequency multiplier has the advantages of high reverse bias resistance, low series resistance, high output power and the like, and the performance of the terahertz frequency multiplier can be remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of terahertz communication, and particularly relates to a charge compensation type Schottky diode with high reverse bias resistance, which is applicable to high-frequency electronic devices such as terahertz frequency multipliers. Background Art

[0002] Due to its unique non-linear effect, the Schottky barrier diode is widely used in high-frequency electronic devices such as terahertz frequency multipliers, mixers, and modulators. However, in a conventional Schottky diode under reverse bias, the electric field distribution is triangular, and the electric field strength is the largest near the Schottky contact. As the reverse bias increases, the electric field strength increases rapidly, resulting in the device being easily broken down. The critical breakdown electric field strength of GaAs (gallium arsenide) material is 4×10 5 KV / cm. When the reverse bias is greater than 3V, the maximum electric field strength in the conventional device exceeds the critical electric field strength, resulting in a low reverse breakdown voltage and limiting the performance of the terahertz frequency multiplier. In addition, although the Schottky diode made of GaN material has a high reverse breakdown voltage, its series resistance is large, which limits the efficiency of the terahertz frequency multiplier. Summary of the Invention

[0003] In order to solve the problems of low reverse breakdown voltage and large series resistance of the Schottky diode in the prior art, the present invention designs a charge compensation type Schottky diode with high reverse bias resistance. By introducing a 10-nm p-type charge compensation layer into the n-type GaAs epitaxial layer, the electric field distribution in the device is adjusted, and most of the electric field is moved to the electric field collection area. At the same time, by reducing the doping concentration of the electric field collection area, the depletion region width in the device is increased and the electric field strength is weakened, so that the Schottky diode can withstand a higher bias voltage.

[0004] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0005] A charge compensation type Schottky diode with high reverse bias resistance includes a semi-insulating GaAs substrate, a GaAs buffer layer, a GaAs ohmic contact layer, a GaAs electric field collection layer, a GaAs charge compensation layer, a GaAs Schottky contact layer, a SiO2 passivation layer formed in sequence from bottom to top, a cathode electrode formed on the ohmic contact layer, and an anode electrode formed on the Schottky contact layer.

[0006] Further, the GaAs buffer layer is n-type doped.

[0007] Further, the GaAs ohmic contact layer is n-type doped.

[0008] Further, the GaAs electric field collection layer is n-type doped.

[0009] Furthermore, the GaAs charge compensation layer is p-type doped.

[0010] Furthermore, the GaAs Schottky contact layer is n-type doped.

[0011] Furthermore, the concentration of the GaAs buffer layer is 1×10 18 cm -3 , the concentration of the GaAs ohmic contact layer is 5×10 18 cm -3 , the concentration of the GaAs electric field collection layer is 5×10 16 cm -3 , the concentration of the GaAs charge compensation layer is 9×10 17 cm -3 , the concentration of the GaAs Schottky contact layer is 2×10 17 cm -3 .

[0012] Furthermore, the thickness of the GaAs buffer layer is 1 μm, the thickness of the GaAs ohmic contact layer is 2 μm, the thickness of the GaAs electric field collection layer is 1 μm, the thickness of the GaAs charge compensation layer is 10 nm, and the thickness of the GaAs Schottky contact layer is 50 nm.

[0013] Furthermore, when the reverse bias voltage of the diode is greater than 10 V, the maximum electric field strength inside the device is lower than the critical breakdown electric field strength of the GaAs material.

[0014] Furthermore, the critical breakdown electric field strength of the GaAs material is 4×10 5 KV / cm.

[0015] Compared with the prior art, the present invention has the following technical advantages:

[0016] (1) The introduction of the p-type charge compensation layer in the present invention is used to adjust the electric field distribution inside the device, move most of the electric field to the electric field collection area, and at the same time increase the depletion region width inside the device and weaken the electric field strength by reducing the doping concentration of the electric field collection area, so that the diode can withstand a higher bias voltage.

[0017] (2) The anode diameter of the diode of the present invention is larger to reduce the series resistance (Rs), and at the same time can withstand a higher input power, thereby increasing the output power of the terahertz frequency multiplier.

[0018] (3) The reverse bias voltage resistance of the diode of the present invention is significantly improved, and when the reverse bias voltage is greater than 10 V, the maximum electric field strength inside the device is still lower than the critical breakdown electric field strength of the GaAs material (4×10 5 KV / cm). Description of the Drawings

[0019] Figure 1 It is a schematic structural diagram of a charge compensation type Schottky diode with high reverse bias resistance.

[0020] Figure 2 It is a distribution diagram of the internal electric field of a conventional Schottky diode under different bias voltages.

[0021] Figure 3 It is a distribution diagram of the internal electric field of a charge compensation type Schottky diode under different bias voltages. Detailed Implementation Modes

[0022] Next, in combination with the embodiments of the present invention and the drawings, the technical solutions in the embodiments of the present invention will be clearly and completely described.

[0023] First, refer to Figure 1 , a charge compensation type Schottky diode with high reverse bias resistance of the present invention includes a semi-insulating GaAs substrate 1, a GaAs buffer layer 2 (n-type doped, concentration 1×10 18 cm -3 , thickness 1 μm), a GaAs ohmic contact layer 3 (n-type doped, concentration 5×10 18 cm -3 , thickness 2 μm), a GaAs electric field collection layer 4 (n-type doped, concentration 5×10 16 cm -3 , thickness 1 μm), a GaAs charge compensation layer 5 (p-type doped, concentration 9×10 17 cm -3 , thickness 10 nm), a GaAs Schottky contact layer 6 (n-type doped, concentration 2×10 17 cm -3 , thickness 50 nm), a SiO2 passivation layer 7, and a cathode electrode 8 formed on the ohmic contact layer and an anode electrode 9 formed on the Schottky contact layer.

[0024] By introducing a p-type charge compensation layer, the present invention adjusts the distribution of the internal electric field of the device, so that the electric field is mainly concentrated in the 1-μm-wide n-type 5×10 16 cm -3 electric field collection area. At the same time, by reducing the doping concentration of the electric field collection area, the depletion region width is increased and the electric field strength is weakened, so that the Schottky diode can withstand a higher reverse bias voltage; as Figure 2 shown, when the reverse bias voltage exceeds 2 V, the electric field strength in the conventional Schottky diode exceeds the breakdown electric field strength and the device breaks down; as Figure 3As shown, when the reverse bias voltage is less than 12 V, the electric field strength of the charge compensation type Schottky diode is less than the breakdown electric field strength. Therefore, this device structure can withstand a higher reverse bias voltage. In addition, the design of a larger anode diameter reduces the series resistance (Rs), and at the same time can withstand a higher input power, thereby increasing the output power of the terahertz frequency multiplier.

[0025] Conclusion

[0026] The present invention proposes a charge compensation type Schottky diode with high reverse bias voltage resistance, which solves the problems of low reverse breakdown voltage and large series resistance of the existing Schottky diodes. This diode can be widely applied in the field of terahertz frequency multipliers, and has the advantages of high reverse bias voltage resistance, low series resistance, high output power, etc., and can significantly improve the performance of terahertz frequency multipliers.

Claims

1. A charge compensation type Schottky diode resistant to high reverse bias voltage, characterized in that: It includes a semi-insulating GaAs substrate, a GaAs buffer layer, a GaAs ohmic contact layer, a GaAs electric field collection layer, a GaAs charge compensation layer, a GaAs Schottky contact layer, a SiO2 passivation layer formed successively from bottom to top, as well as a cathode electrode formed on the ohmic contact layer and an anode electrode formed on the Schottky contact layer.

2. The charge compensation type Schottky diode resistant to high reverse bias according to claim 1, wherein: The GaAs buffer layer is n-type doped.

3. The charge compensation type Schottky diode resistant to high reverse bias according to claim 1, characterized in that: The GaAs ohmic contact layer is n-type doped.

4. The charge compensation type Schottky diode resistant to high reverse bias according to claim 1, characterized in that: The GaAs electric field collection layer is n-type doped.

5. The charge compensation type Schottky diode with high reverse bias voltage resistance according to claim 1, characterized in that: The GaAs charge compensation layer is p-type doped.

6. The charge compensation type Schottky diode resistant to high reverse bias according to claim 1, characterized in that: The GaAs Schottky contact layer is n-type doped.

7. The charge compensation type Schottky diode withstanding high reverse bias according to claim 1, wherein: The concentration of the described GaAs buffer layer is 1×10 18 cm -3 , the concentration of the described GaAs ohmic contact layer is 5×10 18 cm -3 , the concentration of the described GaAs electric field collection layer is 5×10 16 cm -3 , the concentration of the described GaAs charge compensation layer is 9×10 17 cm -3 , the concentration of the described GaAs Schottky contact layer is 2×10 17 cm -3 .

8. The charge compensation type Schottky diode with high reverse bias voltage resistance according to claim 1, characterized in that: The thickness of the GaAs buffer layer is 1 μm, the thickness of the GaAs ohmic contact layer is 2 μm, the thickness of the GaAs electric field collection layer is 1 μm, the thickness of the GaAs charge compensation layer is 10 nm, and the thickness of the GaAs Schottky contact layer is 50 nm.

9. The charge compensation type Schottky diode with high reverse bias resistance according to claim 1, characterized in that: When the reverse bias voltage of the diode is greater than 10 V, the maximum electric field intensity inside the device is lower than the critical breakdown electric field intensity of the GaAs material.

10. The charge compensation type Schottky diode with high reverse bias voltage resistance according to claim 1, characterized in that: The critical breakdown electric field strength of the GaAs material described is 4×10 5 KV / cm.

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