Gallium nitride electronic device with electric field buffer

Abstract

The application discloses a gallium nitride electronic device with an electric field buffer zone, and the structure comprises a substrate, a transition layer, a buffer layer, a channel layer, a barrier layer, a p-GaN layer, a passivation layer, an electric field buffer zone, source metal, drain metal and gate metal. The application introduces an N-type doped electric field buffer zone below the drain, slows down the increase of the electric field intensity near the drain caused by external particles and charges entering the device, effectively increases the single-particle burnout resistance of the device, and can also relieve the increase of the electric field intensity near the drain under other stress conditions, and is suitable for application occasions of power electronic systems, especially space power electronic systems.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of power semiconductors, and is mainly used for space power systems. BACKGROUND

[0002] Gallium nitride (GaN) material is a typical representative of the third generation of wide band gap semiconductors, with a band gap of 3.4 eV, higher critical breakdown field, higher electron saturation drift speed, higher limit operating temperature, smaller dielectric constant, and good chemical stability, etc. It is an excellent material for power electronic power semiconductor devices. Gallium nitride power devices are attractive for space applications due to their size, weight and power efficiency. These excellent properties make gallium nitride power devices an ideal choice for key components of satellite systems operating at high power and high frequency in space environment.

[0003] In space radiation environment, electronic equipment will suffer serious radiation effects. Many research reports have proved that gallium nitride power devices are sensitive to single event effects.

[0004] When high energy particles penetrate the device, single event effects (SEE) occur: high energy particles lose energy and produce electron-hole pair (EHP) tracks, and charges are recombined or extracted out of the device through drift and / or diffusion processes, causing transient current, called single event transient (SET). This current spike can be destructive when large enough, such as single event burnout (SEB), single event gate rupture (SEGR), single event upset (SEU), etc. The severity depends on many parameters, such as device structure, amount of charge generated, device operating point, impact location and internal defects. Single event burnout (SEB) is one of the most important categories of gallium nitride power transistor single event effect failure. Therefore, single event burnout is a serious challenge for the application of gallium nitride power devices in space environment. SUMMARY

[0005] The purpose of the present application is to provide a gallium nitride electronic device with an electric field buffer zone to solve the problem of gallium nitride power devices in space environment. The present application adds an N-type doped electric field buffer zone in the buffer layer of the device based on the original gallium nitride power device. The buffer zone can solve the problem of excessive drain electric field intensity of gallium nitride power devices after single particle injection, thereby greatly improving the single event burnout resistance of gallium nitride power devices.

[0006] To achieve the above-mentioned purpose of the application, the technical scheme of the present application is as follows:

[0007] A gallium nitride electronic device with an electric field buffer zone, comprising a substrate 01, a transition layer 02, a buffer layer 03, a channel layer 04, a barrier layer 05 arranged in sequence; the device has a source metal 10 and a drain metal 11 at both ends of the upper surface of the device, the source metal 10 and the drain metal 11 penetrate the barrier layer 05 in the vertical direction of the device and extend into the channel layer 04; the barrier layer 05 has a gate structure composed of a p-GaN layer 06 and a gate metal 12 on the upper surface, the gate metal 12 is located on the upper surface of the p-GaN layer 06; the barrier layer 05 has a gate-source side passivation layer 07 between the source metal 10 and the gate structure on the upper surface, and a gate-drain side passivation layer 08 between the drain metal 11 and the gate structure on the upper surface, the lateral width of the gate-drain side passivation layer 08 is greater than that of the gate-source side passivation layer 07; the buffer layer 03 has an electric field buffer zone 09 at one end below the drain metal 11, the drain metal 11 is completely above the electric field buffer zone 09, and the lateral width of the electric field buffer zone 09 is greater than that of the drain metal 11;

[0008] The electric field buffer zone 09 is one or a combination of N-type doped gallium nitride, aluminum gallium nitride or aluminum nitride, the doping impurity is Si or Ge, the impurity distribution is uniform doping or non-uniform doping, and the doping concentration is 1×10 15 ~ 1×10 21 cm -3 .

[0009] Specifically, the upper surface of the field buffer zone 09 is in contact with the lower surface of the channel layer 04.

[0010] Specifically, the substrate 01 is one of a silicon substrate, a silicon carbide substrate, a sapphire substrate, a gallium nitride substrate, and an aluminum nitride substrate.

[0011] Specifically, the transition layer 02 uses one or a combination of gallium nitride, aluminum nitride, and aluminum gallium nitride.

[0012] Specifically, the buffer layer 03 uses one or a combination of gallium nitride, aluminum nitride, and aluminum gallium nitride, and the doping element is carbon or iron, and the thickness is 1-10um.

[0013] Specifically, the channel layer 04 uses gallium nitride or aluminum gallium nitride.

[0014] Specifically, the barrier layer 05 uses one or a combination of gallium nitride, aluminum nitride, and aluminum gallium nitride, and the thickness is 5-100nm.

[0015] Specifically, the p-GaN layer 06 uses P-type doped gallium nitride, aluminum nitride, or aluminum gallium nitride.

[0016] Specifically: the material of the gate-source side passivation layer 07 and the gate-drain side passivation layer 08 is one or a combination of multiple of SiN, Al2O3, AlN, SiO2, HfO2, ScO2, TiO2 and ZrO2. x x

[0017] The present application discloses the following technical effects:

[0018] When the GaN HEMT is in the off-state bias, i.e. the source metal 10 voltage V S = 0V, the gate metal 12 voltage V G = 0V, and the drain metal 11 voltage V D is high. After the heavy ion incidence, electron-hole pairs are generated along the ion track. The electron and hole begin to move along the direction of the electric field, and the concentration distribution changes, causing the internal electric field intensity distribution of the device to change. Due to the huge difference in electron and hole mobility in gallium nitride, a large number of electrons can be injected from the source, while the holes injected from the drain are relatively few, and the electric field intensity at the drain gradually increases, eventually reaches the critical electric field of the material, and finally burns out.

[0019] The present application adds an N-type doped electric field buffer zone in the buffer layer of the original gallium nitride power device, which can solve the problem of excessively high drain electric field intensity of the gallium nitride power device after single particle incidence, thereby greatly improving the single particle burnout resistance of the gallium nitride power device. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a cross-sectional schematic diagram of a gallium nitride electronic device with an electric field buffer zone of embodiment 1;

[0021] Figure 2 is a cross-sectional schematic diagram of a gallium nitride electronic device with an electric field buffer zone of embodiment 2;

[0022] Figure 3 is a cross-sectional schematic diagram of a gallium nitride electronic device with an electric field buffer zone of embodiment 3;

[0023] Figure 4 is a cross-sectional schematic diagram of a gallium nitride electronic device with an electric field buffer zone of embodiment 4;

[0024] Figure 5 is a cross-sectional schematic diagram of a gallium nitride electronic device with an electric field buffer zone of embodiment 5;

[0025] Figure 6 is a cross-sectional schematic diagram of a gallium nitride electronic device with an electric field buffer zone of embodiment 6;

[0026] Explanation of reference numerals in the attached figures: 01 is the substrate, 02 is the transition layer, 03 is the buffer layer, 04 is the channel layer, 05 is the barrier layer, 06 is the p-GaN layer, 07 is the gate-source passivation layer, 08 is the gate-drain passivation layer, 09 is the electric field buffer layer, 10 is the source metal, 11 is the drain metal, 12 is the gate metal, and 13 is the gate dielectric layer. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] Example 1

[0030] Reference Figure 1 As shown, this embodiment provides a gallium nitride electronic device with an electric field buffer, characterized by comprising: a substrate 01, a transition layer 02, a buffer layer 03, a channel layer 04, a barrier layer 05, a p-GaN layer 06, a gate-source side passivation layer 07, a gate-drain side passivation layer 08, an electric field buffer 09, a source metal 10, a drain metal 11, and a gate metal 12.

[0031] The bottom layer of the device is substrate 01; transition layer 02 is located above substrate 01; buffer layer 03 is located above transition layer 02; channel layer 04 is located above buffer layer 03; barrier layer 05 is located above channel layer 04; p-GaN layer 06, gate-source passivation layer 07, and gate-drain passivation layer 08 are located above AlGaN barrier layer 05, in the following order from left to right: gate-source passivation layer 07, p-GaN layer 06, and gate-drain passivation layer 08; source metal 10 is located at the leftmost end of the device, above channel layer 01. Above 4, it penetrates the gate-source passivation layer 07, the barrier layer 05, and part of the channel layer 04; the drain metal 11 is located at the rightmost end of the device, above the channel layer 04, and penetrates the gate-drain passivation layer 08, the barrier layer 05, and part of the channel layer 04; the gate metal 12 is located above the p-GaN layer 06; the electric field buffer 09 is located at the rightmost end of the device, below the channel layer 04, and is embedded in the buffer layer 03. It partially overlaps with the drain metal 11 in the vertical direction, and its left side extends between the drain metal 11 and the gate metal 12.

[0032] The electric field buffer zone 09 is N-type doped gallium nitride (GaN) and aluminum gallium nitride (GaN). x Al 1-xThe doping material is one or more of N or aluminum nitride (AlN), and the doping impurity is Si, Ge or other impurities that can become donors in the electric field buffer material. The impurity distribution is uniform or non-uniform doping, and the doping concentration is 1×10⁻⁶. 15 ~1×10 21 cm -3 .

[0033] In some embodiments, substrate 01 may include a silicon substrate, a silicon carbide (SiC) substrate, a sapphire substrate, a gallium nitride substrate, an aluminum nitride substrate, or a substrate formed of other suitable materials.

[0034] In some embodiments, the transition layer 02 may be made of gallium nitride, aluminum nitride, aluminum gallium nitride, or a combination thereof, but is not limited thereto.

[0035] In some embodiments, the buffer layer 03 is made of gallium nitride, aluminum nitride, aluminum gallium nitride, or a combination thereof, but is not limited thereto, and its doping element is carbon or iron, and its thickness is 1 to 10 μm.

[0036] In some embodiments, the channel layer 04 material may include gallium nitride, aluminum gallium nitride, but is not limited thereto.

[0037] In some embodiments, the barrier layer 05 material may include gallium nitride, aluminum nitride, aluminum gallium nitride, or a combination thereof, but is not limited thereto, and its thickness is 5 to 100 nm.

[0038] In some embodiments, the p-GaN layer 06 material is p-type doped gallium nitride, aluminum nitride, or aluminum gallium nitride, but is not limited thereto, and the doping element is magnesium.

[0039] In some embodiments, the gate-source side passivation layer 07 and the gate-drain side passivation layer 08 are made of SiN. x Al2O3, AlN, SiO2, HfO2, ScO2, TiO2, ZrO2 or combinations thereof, but not limited to these.

[0040] Example 2

[0041] Reference Figure 2 As shown, the difference between this embodiment and embodiment 1 is that the upper edge of the electric field buffer zone 09 does not contact the channel layer 04.

[0042] Example 3

[0043] like Figure 3 As shown, the difference between this embodiment and Embodiment 1 is that the left edge of the electric field buffer 09 extends below the gate metal 12.

[0044] Example 4

[0045] likeFigure 4 As shown, the difference between this embodiment and embodiment 1 is that the electric field buffer 09 and the drain metal 11 do not overlap in the vertical direction.

[0046] Example 5

[0047] like Figure 5 As shown, the difference between this embodiment and Embodiment 1 is that Embodiment 1 is an enhancement-type structure, while Embodiment 5 is a depletion-type structure, and the material of the gate dielectric layer 13 is HfO2, Al2O3, SiO2, or SiN. x Or a combination of the above, but not limited to this.

[0048] Example 6

[0049] like Figure 6 As shown, the difference between this embodiment and Embodiment 1 is that Embodiment 1 uses a p-GaN gate structure, while Embodiment 5 uses a MIS gate structure, and the material of the gate dielectric layer 13 is HfO2, Al2O3, SiO2, or SiN. x Or a combination of the above, but not limited to this.

[0050] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0051] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Any modifications and variations made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A gallium nitride electronic device with an electric field buffer, characterized in that, The device includes a substrate (01), a transition layer (02), a buffer layer (03), a channel layer (04), and a barrier layer (05) stacked sequentially. The upper surface of the device has a source metal (10) and a drain metal (11) at both ends, and the source metal (10) and drain metal (11) penetrate the barrier layer (05) and extend into the channel layer (04) along the vertical direction of the device. The upper surface of the barrier layer (05) has a gate structure composed of a p-GaN layer (06) and a gate metal (12), and the gate metal (12) is located on the upper surface of the p-GaN layer (06). A gate-source passivation layer (07) is provided on the upper surface of the barrier layer (05) between the source metal (10) and the gate structure, and a gate-drain passivation layer (08) is provided on the upper surface of the barrier layer (05) between the drain metal (11) and the gate structure. The lateral width of the gate-drain passivation layer (08) is greater than the lateral width of the gate-source passivation layer (07). An electric field buffer (09) is provided at one end of the buffer layer (03) below the drain metal (11). The drain metal (11) is completely located above the electric field buffer (09), and the lateral width of the electric field buffer (09) is greater than the lateral width of the drain metal (11). The upper surface of the electric field buffer (09) does not contact the lower surface of the channel layer (04). The electric field buffer (09) is one or more of N-type doped gallium nitride, aluminum gallium nitride, or aluminum nitride, with Si or Ge as the doping impurity. The impurity distribution is uniform or non-uniform doping, and the doping concentration is 1×10⁻⁶. 15 ~1×10 21 cm -3 .

2. A gallium nitride electronic device with an electric field buffer according to claim 1, characterized in that: The substrate (01) is one of silicon substrate, silicon carbide substrate, sapphire substrate, gallium nitride substrate, and aluminum nitride substrate.

3. A gallium nitride electronic device with an electric field buffer according to claim 1, characterized in that: The transition layer (02) is made of one or more of gallium nitride, aluminum nitride, and aluminum gallium nitride.

4. A gallium nitride electronic device with an electric field buffer according to claim 1, characterized in that: The buffer layer (03) is made of one or more of gallium nitride, aluminum nitride, and aluminum gallium nitride, and the doping element is carbon or iron, with a thickness of 1 to 10 μm.

5. A gallium nitride electronic device with an electric field buffer according to claim 1, characterized in that: The channel layer (04) is made of gallium nitride or aluminum gallium nitride.

6. A gallium nitride electronic device with an electric field buffer according to claim 1, characterized in that: The barrier layer (05) is made of one or more of gallium nitride, aluminum nitride, and aluminum gallium nitride, with a thickness of 5 to 100 nm.

7. A gallium nitride electronic device with an electric field buffer according to claim 1, characterized in that: The p-GaN layer (06) uses p-type doped gallium nitride.

8. A gallium nitride electronic device with an electric field buffer according to claim 1, characterized in that: The passivation layer (07) on the gate-source side and the passivation layer (08) on the gate-drain side are made of SiN. x One or more combinations of Al2O3, AlN, SiO2, HfO2, ScO2, TiO2, and ZrO2.

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