A high voltage wide bandgap diode chip with a trench structure
By introducing the trench structure into the active region and junction terminal area of the high-voltage wide bandgap diode chip, the same set of processes is realized, and the high cost problem caused by the complex process in the prior art is solved, and the production cost is significantly reduced.
Patent Information
- Application Number
- CN201910069030.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2019-01-24
- Publication Date
- 2024-12-20
- Estimated Expiration
- 2039-01-24
AI Technical Summary
The production process of existing wide bandgap semiconductor power devices is complex, resulting in high costs, and a simple and effective design is needed to reduce production costs.
A unified trench structure is introduced in the active region and junction terminal region of the high-voltage wide bandgap diode chip, and the processing of two regions is achieved through the same set of processes, reducing product processing costs.
By introducing the trench structure, the processing process is simplified, the production cost is significantly reduced, while maintaining the high voltage wide bandgap characteristic of the device.
Smart Images
Figure CN109560122B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of wide bandgap semiconductors, and in particular relates to a high-voltage wide bandgap diode chip with a trench structure. Background Art
[0002] With the vigorous development of new energy and the widespread application of power electronics, ordinary Si-based devices cannot meet the application requirements in high-voltage, high-temperature and high-frequency environments. Wide-bandgap semiconductors such as SiC and GaN materials have excellent properties such as high breakdown voltage, low operating loss and high thermal conductivity, which provide possibilities for a new generation of power electronic devices and systems. However, due to the high cost of wide-bandgap semiconductor power devices and the complex manufacturing process of their traditional designs, a simple and effective design is urgently needed to reduce their manufacturing costs. Summary of the invention
[0003] In view of the defects of the prior art, the present invention provides a high-voltage wide bandgap diode chip with a trench structure. The present invention introduces a unified trench structure (004) in the active area (A1) and the junction terminal area (A2), so that the chip can be processed in the two areas with the same set of processes, greatly reducing the product processing cost.
[0004] The technical solution for achieving the purpose of the present invention is:
[0005] A high-voltage wide-bandgap diode chip with a trench structure, comprising:
[0006] A bottom cathode electrode layer (001), a heavily doped N-type semiconductor material layer (002), a lightly doped N-type semiconductor material layer (003), and a trench structure (004) extending from the surface into the lightly doped N-type semiconductor material layer (003);
[0007] The bottom and sidewalls of the trench structure (004) are surrounded by a P-type semiconductor material (005);
[0008] The high-voltage wide bandgap diode chip is divided into an active area (A1) and a junction terminal area (A2), an anode electrode layer (006) is provided on the top of the active area (A1), and a passivation layer (007) is provided on the top of the junction terminal area (A2).
[0009] Wherein, the semiconductor material is a wide bandgap semiconductor material with a bandgap width greater than 2.0 eV, and can be at least one or more of silicon carbide, gallium nitride, gallium oxide, aluminum nitride, and diamond.
[0010] Wherein, the anode electrode layer (006) is composed of at least one of Ti, Ni, Mo, Pt, Si, Al, TiN, W, and Au.
[0011] Wherein, the passivation layer is composed of insulating materials, including at least one of polyimide, silicon dioxide, silicon nitride, and doped or undoped silicon glass.
[0012] The trench structure (004) extends into the lightly doped N-type semiconductor material layer (003) to a depth of 0.1um to 5um, the angle formed between the sidewall and the bottom plane is 80° to 135°, and the minimum thickness of the P-type semiconductor material (005) surrounding the sidewall and the bottom is 0.1um.
[0013] The active area (A1) is arranged in the center of the chip, and a plurality of groove structures (004) exist within the active area, and the shortest distance between two adjacent groove structures (004) is within the range of 0.1um to 10um.
[0014] The junction termination region (A2) is arranged outside the active region (A1) and close to the edge of the chip, and a plurality of groove structures (004) exist within the region. The plurality of groove structures (004) are all strip-shaped and surround the active region (A1).
[0015] The number of the plurality of groove structures (004) is at least 2, and the shortest distance from the inner side of the groove structure (004) closest to the active area (A1) to the outer side of the groove structure (004) farthest from the active area (A1) is greater than 3 times the thickness of the lightly doped N-type semiconductor material layer (003).
[0016] Wherein, during the preparation process of the trench structure (004), etching of the trench structure (004) and doping of the surrounding P-type semiconductor material (005) are defined by the same photolithography process. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a longitudinal section view of an embodiment of the present invention.
[0018] Figure 2 This is a top view of an embodiment of the present invention: the active area has a groove structure with a strip-shaped mesh layout.
[0019] Figure 3 This is a top view of an embodiment of the present invention: the active area has a groove structure with a circular island layout.
[0020] Figure 4 It is a schematic diagram of a possible method for manufacturing the groove structure of the present invention. DETAILED DESCRIPTION
[0021] In order to make the purpose and advantages of the technical solution of the present invention more clearly understood, the present invention is further described in detail below in combination with embodiments and with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
[0022] In the first embodiment of the present invention, the semiconductor material is silicon carbide material.
[0023] In the first embodiment of the present invention, the anode electrode layer (006) is composed of three metals: Ti / TiN / Al.
[0024] In the first embodiment of the present invention, the passivation layer is composed of polyimide.
[0025] In the first embodiment of the present invention, the depth of the trench structure (004) extending into the lightly doped N-type semiconductor material layer (003) is 0.6 um, the angle formed by its side wall and the bottom plane is 100°, and the minimum thickness of the P-type semiconductor material (005) surrounding its side wall and bottom is 0.3 um.
[0026] In the first embodiment of the present invention, the active area (A1) is arranged in the center of the chip, and a plurality of groove structures (004) exist within the active area, and the shortest distance between two adjacent groove structures (004) is 5 um.
[0027] In the first embodiment of the present invention, the number of the plurality of groove structures (004) is 30, and the shortest distance from the inner side of the groove structure (004) closest to the active area (A1) to the outer side of the groove structure (004) farthest from the active area (A1) is 60 um.
[0028] The working principle of this example is:
[0029] The anode electrode layer (006) forms a Schottky contact and an ohmic contact with the lightly doped N-type semiconductor material layer (003) and the P-type semiconductor material (005), respectively. Meanwhile, the cathode electrode layer (001) forms an ohmic contact with the heavily doped N-type semiconductor material layer (002). In the present invention, the current exhibits a conduction characteristic in the direction from the anode electrode layer (006) to the cathode electrode layer (001), and exhibits a blocking characteristic in the opposite direction.
[0030] During the preparation process, the trench structure (004) is etched and doped with the surrounding P-type semiconductor material (005) by the same photolithography process, thereby greatly reducing the processing cost.
Claims
1. A method for manufacturing a high-voltage wide bandgap diode chip with a trench structure, characterized in that: include: From bottom to top, a bottom cathode electrode layer (001), a heavily doped N-type semiconductor material layer (002) and a lightly doped N-type semiconductor material layer (003), and a trench structure (004) extending from the surface into the lightly doped N-type semiconductor material layer (003); The bottom and sidewalls of the trench structure (004) are surrounded by a P-type semiconductor material (005); The high-voltage wide bandgap diode chip is divided into an active area (A1) and a junction terminal area (A2); an anode electrode layer (006) is provided on the top of the active area (A1) and in the groove structure of the active area; and a passivation layer (007) is provided on the top of the junction terminal area (A2) and in the groove structure of the junction terminal area; During the preparation process, the active area and the trench structure (004) of the junction terminal area (A2) are etched by the same photolithography process, and then the P-type semiconductor material (005) at the bottom and side walls of the entire trench structure is doped. The anode electrode layer (006) forms a Schottky contact and an Ohmic contact with the lightly doped N-type semiconductor material layer (003) and the P-type semiconductor material (005), respectively.
2. The method for manufacturing a high voltage wide bandgap diode chip with a trench structure according to claim 1, characterized in that: The heavily doped N-type semiconductor material layer (002), the lightly doped N-type semiconductor material layer (003) and the P-type semiconductor material (005) are composed of at least one or more of silicon carbide, gallium nitride, gallium oxide, aluminum nitride and diamond, and have a bandgap width greater than 2.0 eV.
3. The method for manufacturing a high voltage wide bandgap diode chip with a trench structure according to claim 1, characterized in that: The anode electrode layer (006) is composed of at least one of Ti, Ni, Mo, Pt, Si, Al, TiN, W, and Au.
4. The method for manufacturing a high voltage wide bandgap diode chip with a trench structure according to claim 1, characterized in that: The passivation layer (007) is composed of an insulating material, including at least one of polyimide, silicon dioxide, silicon nitride, and doped or undoped silicon glass.
5. The method for manufacturing a high voltage wide bandgap diode chip with a trench structure according to claim 1, characterized in that: The depth of the groove structure (004) extending into the lightly doped N-type semiconductor material layer (003) is 0.1um to 5um, the angle formed by its side wall and the bottom plane is 80° to 135°, and the minimum thickness of the P-type semiconductor material (005) surrounding the side wall and bottom of the groove structure (004) is 0.1um.
6. The method for manufacturing a high voltage wide bandgap diode chip with a trench structure according to claim 1, characterized in that: The active area (A1) is arranged in the center of the chip, and a plurality of groove structures (004) exist within the active area, and the shortest distance between two adjacent groove structures (004) is within the range of 0.1um to 10um.
7. The method for manufacturing a high voltage wide bandgap diode chip with a trench structure according to claim 1, characterized in that: The junction terminal region (A2) is arranged outside the active region (A1) and close to the edge of the chip, and a plurality of groove structures (004) exist within the region. The plurality of groove structures (004) are all strip-shaped and surround the active region (A1).
8. The method for manufacturing a high voltage wide bandgap diode chip with a trench structure according to claim 7, characterized in that: The number of the plurality of groove structures (004) is at least 2, and the shortest distance from the inner side of the groove structure (004) closest to the active area (A1) to the outer side of the groove structure (004) farthest from the active area (A1) is greater than 3 times the thickness of the lightly doped N-type semiconductor material layer (003).