Beta-Ga2O3 heterojunction diode structure

Abstract

The invention provides a beta-Ga2O3 heterojunction diode structure. The beta-Ga2O3 heterojunction diode structure sequentially comprises cathode metal, an N + substrate region and an N-drift region from bottom to top, the P-well region is divided into a left part and a right part which are located on the upper surface of the N-drift region, and the P-plus region is divided into a left part and a right part which are located on the upper surfaces of the P-well region and part of the N-drift region; and an anode metal. According to the beta-Ga2O3 heterojunction diode structure and the P-NiO structure, a depletion region can be expanded, the distribution of an electric field at the edge of a main junction can be optimized, the distribution of the electric field is smoother and more uniform, the negative influence caused by an electric field concentration effect is eliminated, the reverse breakdown voltage is increased, and the reverse characteristic is greatly improved compared with that of a traditional structure.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a β-Ga2O3 heterojunction diode structure. Background Art

[0002] In power electronics applications, the breakdown voltage of β-Ga2O3 heterojunction diodes is significantly lower than the theoretical limit due to severe edge electric field concentration. When the heterojunction diode is reverse biased, the high electric field concentration near the heterojunction edge causes breakdown to occur preferentially near the heterojunction, severely degrading the device's breakdown characteristics. Therefore, designing a structure to mitigate this electric field concentration effect and further enhance the performance of β-Ga2O3 heterojunction diodes is crucial in β-Ga2O3 research. Summary of the Invention

[0003] In order to solve the problems of the above-mentioned traditional β-Ga2O3 heterojunction diode, the present invention proposes a β-Ga2O3 heterojunction diode structure. The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0004] One embodiment of the present invention provides a β-Ga2O3 heterojunction diode structure, comprising:

[0005] N-drift region (3);

[0006] An N+ substrate region (2) located on the lower surface of the N-drift region (3);

[0007] A cathode metal (1) is located on the lower surface of the N+ substrate region (2);

[0008] The P-well region is divided into two parts, the left P-well region (4-1) and the right P-well region (4-2) are located on the upper surface of the N-drift region (3);

[0009] The P+ region is divided into two parts, the left P+ region (5-1) is located on the upper surface of the left P-well region (4-1) and a portion of the N-drift region (3), and the right P+ region (5-2) is located on the upper surface of the right P-well region (4-2) and a portion of the N-drift region (3);

[0010] Anode metal (7) is located on the upper surfaces of the left P+ region (5-1), the right P+ region (5-2) and part of the N-drift region (3).

[0011] Preferably, the N-drift region (3) is Ga2O3, the doping type is N-type epitaxial doping, the doping element is tin, and the doping concentration is 1×10 16 ~5×10 16 cm-3 , thickness is 10~15μm.

[0012] Preferably, the N+ substrate region (2) is Ga2O3, the doping type is N-type epitaxial doping, the doping element is tin, and the doping concentration is 1×10 18 ~1×10 19 cm -3 .

[0013] Preferably, the P-well regions (4-1) and (4-2) are P-type doped, the doping element is lithium, and the doping concentration is 1×10 17 ~1×10 18 cm -3 , thickness is 0.5~1.5μm.

[0014] Preferably, the P+ regions (5-1) and (5-2) are P-type doped, the doping element is lithium, and the doping concentration is 1×10 18 ~1×10 19 cm -3 , thickness is 0.5~1.5μm.

[0015] Preferably, the cathode metal (1) is a Ti / Al / Ti / Au laminated metal material with a thickness of 20 / 150 / 50 / 80 nm, which is used to form a Schottky contact.

[0016] Preferably, the anode metal (7) is a Ni / Au laminated metal material with a thickness of 50 / 100 nm, which is used to form an ohmic contact.

[0017] This invention proposes a β-Ga2O3 heterojunction diode structure with significantly improved reverse characteristics compared to conventional β-Ga2O3 heterojunction diode structures. The P-NiO structure in this structure expands the depletion region, making the electric field distribution smoother and more uniform, thereby improving the device's reverse characteristics. Compared with conventional structures, by varying the doping concentration, position, width, and length of the P-NiO structure, the electric field distribution at the main junction edge is further optimized, eliminating the negative effects of electric field concentration, increasing the reverse breakdown voltage, and significantly improving the reverse characteristics compared to conventional structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A β-Ga2O3 heterojunction diode structure proposed by the present invention;

[0019] Figure 2 It is a traditional β-Ga2O3 heterojunction diode structure;

[0020] Figure 3Comparison curve of breakdown voltage between the β-Ga2O3 heterojunction diode structure proposed by the present invention and the traditional structure;

[0021] Figure 4 This is the electric field distribution diagram of the new β-Ga2O3 heterojunction diode structure during breakdown;

[0022] Figure 5 This is the electric field distribution diagram of the traditional β-Ga2O3 heterojunction diode structure during breakdown;

[0023] Figure 6 Comparison curve of the lateral electric field intensity between the new β-Ga2O3 heterojunction diode structure and the traditional structure during breakdown;

[0024] Figure 7 This is a comparison curve of the longitudinal electric field intensity between the new β-Ga2O3 heterojunction diode structure and the traditional structure during breakdown. DETAILED DESCRIPTION

[0025] The principles and features of the present invention are described with reference to the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0026] Example 1

[0027] A β-Ga2O3 heterojunction diode structure in this embodiment includes:

[0028] N-drift region (3);

[0029] An N+ substrate region (2) located on the lower surface of the N-drift region (3);

[0030] A cathode metal (1) is located on the lower surface of the N+ substrate region (2);

[0031] The P-well region is divided into two parts, the left P-well region (4-1) and the right P-well region (4-2) are located on the upper surface of the N-drift region (3);

[0032] The P+ region is divided into two parts, the left P+ region (5-1) is located on the upper surface of the left P-well region (4-1) and a portion of the N-drift region (3), and the right P+ region (5-2) is located on the upper surface of the right P-well region (4-2) and a portion of the N-drift region (3);

[0033] Anode metal (7) is located on the upper surfaces of the left P+ region (5-1), the right P+ region (5-2) and part of the N-drift region (3).

[0034] Furthermore, the N-drift region (3) is Ga2O3, the doping type is N-type epitaxial doping, the doping element is tin, and the doping concentration is 1×1016 ~5×10 16 cm -3 , thickness is 10~15μm.

[0035] Furthermore, the N+ substrate region (2) is Ga2O3, the doping type is N-type epitaxial doping, the doping element is tin, and the doping concentration is 1×10 18 ~1×10 19 cm -3 .

[0036] Furthermore, the P-well regions (4-1) and (4-2) are P-type doped, the doping element is lithium, and the doping concentration is 1×10 17 ~1×10 18 cm -3 , thickness is 0.5~1.5μm.

[0037] Furthermore, the P+ regions (5-1) and (5-2) are P-type doped, the doping element is lithium, and the doping concentration is 1×10 18 ~1×10 19 cm -3 , thickness is 0.5~1.5μm.

[0038] Furthermore, the cathode metal (1) is a Ti / Al / Ti / Au laminated metal material with a thickness of 20 / 150 / 50 / 80 nm, and is used to form a Schottky contact.

[0039] Furthermore, the anode metal (7) is a Ni / Au laminated metal material with a thickness of 50 / 100 nm, and is used to form an ohmic contact.

[0040] When the device breaks down in reverse, Figure 3 The breakdown voltage comparison curve shows that the breakdown voltage of the β-Ga2O3 heterojunction diode structure proposed in this paper is much greater than that of the traditional β-Ga2O3 heterojunction diode structure; Figure 4 and Figure 5 From the electric field distribution diagram, it can be seen that the electric field of the new structure is concentrated at the edges of the P-well region (4-1) and (4-2) and the P+ region (5-1) and (5-2), while the electric field of the traditional structure is concentrated near the main junction edge (6-1) and (6-2), and the electric field of the traditional structure is significantly higher than that of the new structure. The specific data curves of the lateral electric field intensity and the longitudinal electric field intensity of the new β-Ga2O3 heterojunction diode structure and the traditional structure at breakdown are shown in Figure 2. Figure 6 and Figure 7As shown, the new structure's peak lateral electric field intensity is significantly lower than that of the traditional structure, and its peak longitudinal electric field intensity is also lower than that of the traditional structure. This new structure optimizes the electric field distribution at the edge of the main junction, eliminating the negative impact of electric field concentration effects, resulting in a 20% increase in reverse breakdown voltage compared to the traditional structure, significantly improving reverse characteristics.

[0041] In the description of the present invention, the terms “first” and “second” are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating that the indicated technical features implicitly include one or more of the features.

[0042] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A β-Ga2O3 heterojunction diode structure, characterized in that: include: N-drift region (3); An N+ substrate region (2) located on the lower surface of the N-drift region (3); A cathode metal (1) is located on the lower surface of the N+ substrate region (2); The P-well region is divided into two parts, the left P-well region (4-1) and the right P-well region (4-2) are located on the upper surface of the N-drift region (3); The P+ region is divided into two parts, the left P+ region (5-1) is located on the upper surface of the left P-well region (4-1) and a portion of the N-drift region (3), and the right P+ region (5-2) is located on the upper surface of the right P-well region (4-2) and a portion of the N-drift region (3); Anode metal (7) is located on the upper surfaces of the left P+ region (5-1), the right P+ region (5-2) and part of the N-drift region (3).

2. A β-Ga2O3 heterojunction diode structure according to claim 1, characterized in that: The N-drift region (3) is Ga2O3, the doping type is N-type epitaxial doping, the doping element is tin, and the doping concentration is 1×10 16 ~5×10 16 cm -3 , thickness is 10~15μm.

3. A β-Ga2O3 heterojunction diode structure according to claim 1, characterized in that: The P-well regions (4-1) and (4-2) are P-type doped, with lithium as the doping element and a doping concentration of 1×10 17 ~1×10 18 cm -3 , thickness is 0.5~1.5μm.

4. A β-Ga2O3 heterojunction diode structure according to claim 1, characterized in that: The P+ regions (5-1) and (5-2) are P-type doped, with lithium as the doping element and a doping concentration of 1×10 18 ~1×10 19 cm -3 , thickness is 0.5~1.5μm.

5. A β-Ga2O3 heterojunction diode structure according to claim 1, characterized in that: The cathode metal (1) is a Ti / Al / Ti / Au laminated metal material with a thickness of 20 / 150 / 50 / 80 nm, and is used to form a Schottky contact.

6. A β-Ga2O3 heterojunction diode structure according to claim 1, characterized in that: The anode metal (7) is a Ni / Au laminated metal material with a thickness of 50 / 100 nm and is used to form an ohmic contact.

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