A heterojunction bipolar transistor device with piezoelectric effect and a method of fabricating the same

Abstract

The application belongs to the technical field of microelectronics and piezoelectric electronics, and relates to a heterojunction bipolar transistor device with a piezoelectric effect and a preparation method thereof. The application discloses a heterojunction bipolar transistor device with a piezoelectric effect and a preparation method thereof. The application discloses a heterojunction bipolar transistor device with a piezoelectric effect and a preparation method thereof. The application discloses a heterojunction bipolar transistor device with a piezoelectric effect and a preparation method thereof. The application discloses a heterojunction bipolar transistor device with a piezoelectric effect and a preparation method thereof. The application discloses a heterojunction bipolar transistor device with a piezoelectric effect and a preparation method thereof. The application discloses a heterojunction bipolar transistor device with a piezoelectric effect and a preparation method thereof. The application discloses a heterojunction bipolar transistor device with a piezoelectric effect and a preparation method thereof. The application discloses a heterojunction bipolar transistor device with a piezoelectric effect and a preparation method thereof. The application discloses a heterojunction bipolar transistor device with a piezoelectric effect and a preparation method thereof. The application discloses a heterojunction bipolar transistor device with a piezoelectric effect and a preparation method thereof. The application discloses a heterojunction bipolar transistor device with a piezoelectric effect and a preparation method thereof. The application discloses a heterojunction bipolar transistor device with a piezoelectric effect and a preparation method thereof. The application discloses a heterojunction bipolar transistor device with a piezoelectric effect and a preparation method thereof. The application discloses a heterojunction bipolar transistor device with a piezoelectric effect and a preparation method thereof. The application discloses a heterojunction bipolar transistor device with a piezoelectric effect and a preparation method thereof. The application discloses a heterojunction bipolar transistor device with a piezoelectric effect and a preparation method thereof. The application discloses a heterojunction bipolar transistor device with a piezoelectric effect and a preparation method thereof. The application discloses a heterojunction bipolar transistor device with a piezoelectric effect and a preparation method thereof. The application discloses a heterojunction bipolar transistor device with a piezoelectric effect and a preparation method thereof. The application discloses a heter

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of microelectronics and piezoelectronics, and particularly relates to a heterojunction bipolar transistor device with piezoelectric effect and a preparation method thereof. BACKGROUND

[0002] Zinc oxide (ZnO) as a wide-bandgap semiconductor material with piezoelectric effect and excellent photoelectric properties has attracted extensive attention in recent years. ZnO is a N-type conductive direct bandgap semiconductor with a bandgap of 3.37 eV, and has a large exciton binding energy (60 meV), which makes it have strong exciton luminescence effect at room temperature. Due to its unique piezoelectric properties, ZnO has great application potential in sensors, optoelectronic devices and nanoelectronic devices. However, there are some technical drawbacks and defects in the practical application of ZnO material, for example, the stability and controllability of its piezoelectric properties are relatively poor, and the integration compatibility with existing semiconductor materials is limited, which restricts its application in high-performance electronic and optoelectronic devices.

[0003] Among existing semiconductor materials, silicon (Si) is widely used in various electronic devices due to its excellent semiconductor performance and mature integrated circuit industry foundation. Si has stable electrical properties and mature manufacturing processes, but its piezoelectric effect is weak, which limits its application in piezoelectric sensors and energy harvesting devices. In addition, the photoelectric properties of Si also have certain limitations compared to wide-bandgap semiconductor materials such as ZnO, especially in high-frequency and high-power application scenarios.

[0004] In the existing technology related to ZnO-Si heterojunction, ZnO nanowires have been widely studied due to their unique piezoelectric properties. However, these studies face some challenges: first, the design of nanowire device structure requires strict control of the size and arrangement of nanowires; second, the preparation process of ZnO nanowires is relatively complex, involving precise control of growth conditions. In addition, due to the small size of ZnO nanowire structure, it is a technical challenge to screen out nanowires with desired structure, which requires precise characterization and screening technology. This limits the device research and application potential of ZnO-Si heterojunction at different scales. Although the existing technology combines the piezoelectric properties of ZnO and the semiconductor properties of Si in the study of ZnO-Si heterojunction structure, the preparation cost of such heterojunction in the existing technology is relatively high. SUMMARY

[0005] In view of defects of the prior art, the application provides a heterojunction bipolar transistor device with piezoelectric effect and a preparation method thereof, aiming to solve the technical problems of the prior art that there are difficulties in interface stability and electrical property regulation of ZnO nanowire devices, and small current gain, so as to improve the stability and regulatability of piezoelectric regulation effect, improve the current gain, and realize the regulation ability of stress on electrical properties.

[0006] According to a first aspect of the application, a heterojunction bipolar transistor device with piezoelectric effect is provided, which has a structure comprising a substrate, an insulating layer, an emitter region, a collector region and a metal electrode; the substrate is a convex structure, and the middle convex part of the substrate is referred to as a base region, and the non-convex part at both ends of the substrate is referred to as a substrate; the insulating layer is covered on the substrate at both ends, and the emitter region and the collector region are respectively located on the insulating layer at both ends of the substrate; the metal electrode comprises a first metal electrode, a second metal electrode and a third metal electrode; the first metal electrode, the second metal electrode and the third metal electrode are respectively arranged on the collector region, the emitter region and the base region, and do not contact each other; the materials of the emitter region and the collector region are both N-type ZnO, and the substrate is silicon.

[0007] Preferably, the thickness of the emitter region and the collector region is the same, and the thickness is 0.5-2 um.

[0008] Preferably, the materials of the first metal electrode, the second metal electrode and the third metal electrode are independently selected from titanium-gold composite materials or titanium-aluminum composite materials; when the material of the electrode is titanium-gold composite material, the top layer is gold and the bottom layer is titanium; when the material of the electrode is titanium-aluminum composite material, the top layer is aluminum and the bottom layer is titanium.

[0009] Preferably, the thickness of the bottom layer is 5-20 nm, and the thickness of the top layer is 80-150 nm.

[0010] Preferably, the material of the insulating layer is selected from SiO2, Si3N4 or HfO2.

[0011] According to another aspect of the application, a preparation method of the heterojunction bipolar transistor device with piezoelectric effect is provided, and the specific steps are as follows.

[0012] (1) selecting a substrate;

[0013] (2) etching the substrate to form a convex structure, and the middle convex part of the substrate is referred to as a base region, and the non-convex part at both ends of the substrate is referred to as a substrate;

[0014] (3) performing thermal oxidation on the convex structure obtained in step (2) to form a thermal oxidation layer on the convex structure;

[0015] (4) using dry etching to remove the thermal oxide layer of the base region of the structure obtained in step (3), and the thermal oxide layer remaining on the substrate is an insulating layer;

[0016] (5) respectively preparing an emission region and a collector region on the insulating layer prepared in step (4) by magnetron sputtering;

[0017] (6) respectively depositing a first metal electrode, a second metal electrode and a third metal electrode on the collector region, the emission region and the base region by electron beam evaporation, and the first metal electrode, the second metal electrode and the third metal electrode do not contact each other.

[0018] Preferably, the substrate in step (1) is pretreated, and the pretreatment specifically comprises washing with acetone, then washing with anhydrous ethanol, then washing with deionized water, and finally blowing dry with a nitrogen gun.

[0019] Preferably, the specific temperature of the thermal oxidation in step (3) is 850-1000℃, and the time of the thermal oxidation is 10-30min.

[0020] Preferably, the sputtering power of the magnetron sputtering in step (5) is 180-300W, and the sputtering time is 1-2h.

[0021] Overall, compared with the prior art, the above technical solutions conceived by the present application mainly have the following technical advantages:

[0022] (1) The present application combines the piezoelectric properties of ZnO and the excellent semiconductor properties of Si to form a high-efficiency heterojunction structure, which combines the piezoelectric properties of ZnO and the excellent semiconductor properties of Si, not only realizes good current transmission, but also utilizes the piezoelectric properties of ZnO to regulate its electrical properties by applying stress, not only satisfies the electrical properties of the bipolar transistor in structure, but also effectively realizes force-electric coupling to regulate the electrical properties, aims to regulate the current gain of the transistor by stress, the heterojunction structure can improve the switching speed of the device, improve the current gain, and has high sensitivity and linearity, and is suitable for high-performance electronic and optoelectronic devices.

[0023] (2) The present application effectively isolates the direct contact between the piezoelectric material and the substrate by introducing an insulating layer, avoids longitudinal loss of current, reduces leakage, and more charges are transmitted between the emission region, the base region and the collector region, thereby improving the current transmission efficiency.

[0024] (3) The present application adopts a horizontal structure design, and the emission region, the collector region and the base region of the device are in the same plane, and this lateral distribution of each region is more convenient for stress application and more sensitive to strain sensing.

[0025] (4) The process steps of the present application are simple and the parameters are easy to control. The innovative structure not only has excellent device characteristics, but also has a wide application prospect. The built-in electric field at the heterojunction interface allows the device to operate at low voltage, thereby reducing energy consumption. At the same time, the stable electrical characteristics provided by the heterojunction effectively prevent unnecessary charge transfer, further improving the long-term reliability of the device. In addition, the structure allows the combination of various physical property materials, providing more possibilities for the design of multi-purpose electronic elements. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a structure diagram of a heterojunction bipolar transistor device with piezoelectric effect provided by embodiment 1 of the present application.

[0027] Among them, 1, collector region; 2 metal electrode; 3, substrate; 4, emitter region; 5, insulating layer. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and not to limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0029] Embodiment 1

[0030] As shown in Figure 1 , a heterojunction bipolar transistor device with piezoelectric effect, its structure includes, substrate 3, insulating layer 5, emitter region 4, collector region 1 and metal electrode 2, the substrate 3 is convex structure, record the middle convex part of the substrate 3 as base region, the two ends of the substrate 3 are not convex part as substrate, the two ends of the substrate 3 are covered with the insulating layer 5, the emitter region 4 and the collector region 1 are respectively located on the insulating layer 5 at both ends of the substrate 3, the metal electrode 2 includes first metal electrode, second metal electrode, third metal electrode, the first metal electrode, second metal electrode, third metal electrode are respectively arranged on the collector region 1, emitter region 4 and base region, and do not contact with each other, the emitter region 4 and the collector region 1 are both N type ZnO, and the substrate 3 is silicon. The thickness of the emitter region 4 and the collector region 1 is 1 um; the material of the first metal electrode, the second metal electrode and the third metal electrode is titanium aluminum composite material, the top layer is aluminum, the bottom layer is titanium, the thickness of the bottom layer is 10 nm, and the thickness of the top layer is 90 nm; the material of the insulating layer 5 is selected from SiO2.

[0031] Embodiment 2

[0032] The application provides a preparation method of a heterojunction bipolar transistor device with a piezoelectric effect, and the specific steps are as follows:

[0033] 1. Select a P-type silicon substrate, and the specific operation is as follows: first, clean and remove organic dirt by ultrasonic cleaning with acetone solution for 10 minutes; then, clean and remove acetone by ultrasonic cleaning with anhydrous ethanol for 10 minutes, rinse with deionized water, and dry by using a nitrogen gun.

[0034] 2. Etching of the emitter region and the collector region: photoresist spinning, exposure and development: spin the photoresist on the P-type silicon substrate, the spinning speed is set to 1000 r / min for 10 seconds, then accelerate to 4000 r / min for 30 seconds, use negative photoresist, the temperature is set to 97 DEG C, and bake for 2 minutes, the exposure time of the photoetch machine is 8 seconds. Etching is performed; after etching is completed, the photoresist residue is removed, deionized water is used for cleaning and nitrogen is used for drying.

[0035] 3. Insulating layer preparation: heat oxidation is performed at a temperature of 950 DEG C, and the oxidation time is 15 minutes, so as to form a 50 nm thick SiO2 insulating layer.

[0036] 4. The oxidation layer removal operation on the base region is performed by using a negative photoresist process dry etching.

[0037] 5. Emitter region N-type ZnO film deposition: a positive photoresist process is used to prepare a target pattern. N-type ZnO film is deposited by using a magnetron sputtering method, and the thickness is controlled to be 0.5 um. The sputtering parameters are as follows: power 180 W, argon-oxygen ratio 87.2:1.6 (sccm), and sputtering time 1 hour. After sputtering is completed, the photoresist is removed according to the process steps.

[0038] 6. Collector region N-type ZnO film deposition: a positive photoresist process is used to prepare a target pattern. N-type ZnO film is deposited by using a magnetron sputtering method, and the thickness is controlled to be 0.5 um. The sputtering parameters are as follows: power 180 W, argon-oxygen ratio 87.2:1.6 (sccm), and sputtering time 1 hour. After sputtering is completed, the photoresist is removed according to the process steps.

[0039] 7. Electrode evaporation: a negative photoresist process is used to prepare electrode patterns to divide X, Y and Z regions, and electrodes are evaporated on the collector region, the emitter region and the base region by using an electron beam evaporation: Ti is evaporated as a bottom layer, and the thickness is 10 nm. Au is evaporated as a top layer, and the thickness is 150 nm, so as to form a first metal electrode, a second metal electrode and a third metal electrode.

[0040] Example 3

[0041] The application provides a preparation method of a heterojunction bipolar transistor device with a piezoelectric effect, and the specific steps are as follows:

[0042] 1. Select P-type silicon substrate, the specific operation is: first use acetone solution ultrasonic 10 min, clean and remove organic dirt; then use anhydrous ethanol ultrasonic 10 min, clean and remove acetone, use nitrogen gun to dry;

[0043] 2. Etching emission area and collector area: photoresist spin coating, exposure and development: spin coating photoresist on P-type silicon substrate, spin coating speed is set to 1000 r / min spin coating 10 seconds, then accelerate to 4000 r / min spin coating 30 seconds, use negative glue, temperature setting is 97 DEG C, baking 2 minutes, use photoetching machine, exposure time is 8 seconds. Etching; after etching, remove photoresist residue, use deionized water to clean and dry with nitrogen.

[0044] 3. Insulating layer preparation: heat oxidation at 850 DEG C temperature, oxidation time is 30 minutes, form 100 nm thick SiO2 insulating layer.

[0045] 4. Adopt negative glue process dry etching to remove oxide layer operation on base area.

[0046] 5. Emission area N-type ZnO film deposition: use positive glue process to prepare target pattern. Adopt magnetron sputtering method to deposit N-type ZnO film, control thickness to be 1 μm. Sputtering parameters: power 180 W, argon oxygen ratio is 87.2:1.6 (sccm), sputtering time is 2 hours. After sputtering, remove glue according to the process steps described above.

[0047] 6. Collector area N-type ZnO film deposition: use positive glue process to prepare target pattern. Adopt magnetron sputtering method to deposit N-type ZnO film, control thickness to be 1 μm. Sputtering parameters: power 180 W, argon oxygen ratio is 87.2:1.6 (sccm), sputtering time is 2 hours. After sputtering, remove glue according to the process steps described above.

[0048] 7. Electrode evaporation: adopt negative glue process to prepare electrode pattern to divide X, Y, Z area, adopt electron beam evaporation to evaporate electrode in collector area, emission area, and base area: evaporate Ti as bottom layer, thickness is 50 nm. Evaporate Au as top layer, thickness is 150 nm, form first metal electrode, second metal electrode, third metal electrode respectively.

[0049] Example 4

[0050] A preparation method of a heterojunction bipolar transistor device with piezoelectric effect is provided, and the specific steps are as follows:

[0051] 1. Select P-type silicon substrate, the specific operation is: first use acetone solution ultrasonic 10 min, clean and remove organic dirt; then use anhydrous ethanol ultrasonic 10 min, clean and remove acetone, use nitrogen gun to dry;

[0052] 2. Etching the emitter region and the collector region: photoresist spin coating, exposure and development: spin coating photoresist on the P-type silicon substrate, the spin coating speed is set to 1000 r / min for 10 seconds, then accelerated to 4000 r / min for 30 seconds, using AZ5214 negative photoresist, the temperature is set to 97°C, baking for 2 minutes, using MA8 photoetching machine, the exposure time is 8 seconds. Etching is carried out; after etching is completed, the photoresist residue is removed, deionized water is used for cleaning and nitrogen is used for drying.

[0053] 3. Insulating layer preparation: thermal oxidation is carried out at a temperature of 900°C, and the oxidation time is 30 minutes to form a SiO2 insulating layer.

[0054] 4. The oxidation layer removal operation is carried out on the base region by using a negative photoresist process dry etching.

[0055] 5. Emitter region N-type ZnO film deposition: using a positive photoresist process to prepare the target pattern. N-type ZnO film is deposited by using a magnetron sputtering method, and the thickness is controlled to be about 0.8 μm. The sputtering parameters are: power 180 W, argon-oxygen ratio 87.2:1.6 (sccm), and sputtering time 1.5 hours. After sputtering is completed, the photoresist is removed according to the process steps.

[0056] 6. Collector region N-type ZnO film deposition: using a positive photoresist process to prepare the target pattern. N-type ZnO film is deposited by using a magnetron sputtering method, and the thickness is controlled to be about 0.8 μm. The sputtering parameters are: power 180 W, argon-oxygen ratio 87.2:1.6 (sccm), and sputtering time 1.5 hours. After sputtering is completed, the photoresist is removed according to the process steps.

[0057] 7. Electrode evaporation: using a negative photoresist process to prepare the electrode pattern to divide X, Y, Z regions, and using electron beam evaporation to evaporate electrodes on the collector region, the emitter region, and the base region: evaporating Ti as the bottom layer, and the thickness is 20 nm. Evaporating Au as the top layer, and the thickness is 80 nm, to form a first metal electrode, a second metal electrode, and a third metal electrode, respectively.

[0058] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present application, and is not used to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A heterojunction bipolar transistor device having a piezoelectric effect, characterized by, The structure comprises a substrate (3), an insulating layer (5), an emitting region (4), a collecting region (1) and a metal electrode (2); the substrate (3) is a convex structure, the middle convex part of the substrate (3) is a base region, and the two end non-convex parts are substrates; the insulating layer (5) is covered on the two end substrates of the substrate (3), and the emitting region (4) and the collecting region (1) are respectively located on the insulating layer (5) at the two ends of the substrate (3); the metal electrode (2) comprises a first metal electrode, a second metal electrode and a third metal electrode, the first metal electrode, the second metal electrode and the third metal electrode are respectively arranged on the collecting region (1), the emitting region (4) and the base region, and do not contact each other; the materials of the emitting region (4) and the collecting region (1) are both N-type ZnO, and the substrate (3) is P-type silicon; the side surfaces of the N-type ZnO of the emitting region (4) and the collecting region (1) respectively contact the side surfaces of the P-type silicon of the base region to form a heterojunction.

2. A heterojunction bipolar transistor device with piezoelectric effect according to claim 1, wherein, The thickness of the emitting region (4) and the collecting region (1) is the same, and the thickness is 0.5-2 μm.

3. The heterojunction bipolar transistor device with piezoelectric effect of claim 1, wherein, The materials of the first metal electrode, the second metal electrode and the third metal electrode are independently selected from titanium-gold composite material or titanium-aluminum composite material; when the material of the electrode is titanium-gold composite material, the top layer is gold and the bottom layer is titanium; when the material of the electrode is titanium-aluminum composite material, the top layer is aluminum and the bottom layer is titanium.

4. A heterojunction bipolar transistor device with piezoelectric effect according to claim 3, wherein, The thickness of the bottom layer is 5-20 nm, and the thickness of the top layer is 80-150 nm.

5. The heterojunction bipolar transistor device with piezoelectric effect of claim 1, wherein, The material of the insulating layer (5) is selected from SiO2, Si3N4 or HfO2.

6. A method of manufacturing a heterojunction bipolar transistor device having a piezoelectric effect as claimed in any one of claims 1 to 4, characterized in that, The specific steps are as follows: (1) selecting a substrate; (2) etching the substrate to form a convex structure, the middle convex part of the substrate is a base region, and the two end non-convex parts are substrates; (3) performing thermal oxidation on the convex structure obtained in step (2) to form a thermal oxidation layer on the convex structure; (4) removing the thermal oxidation layer of the base region of the structure obtained in step (3) by dry etching, and retaining the thermal oxidation layer on the substrate as an insulating layer; (5) preparing an emitting region and a collecting region on the insulating layer prepared in step (4) by magnetron sputtering respectively; (6) depositing a first metal electrode, a second metal electrode and a third metal electrode on the collecting region, the emitting region and the base region respectively by electron beam evaporation, and making the first metal electrode, the second metal electrode and the third metal electrode not contact each other.

7. The method of claim 6, wherein the heterojunction bipolar transistor device having piezoelectric effect is prepared by the steps of: The substrate in step (1) is pretreated, and the pretreatment specifically comprises the following steps: first washing with acetone, then washing with anhydrous ethanol, then washing with deionized water, and finally blowing dry with a nitrogen gun.

8. The method of claim 6, wherein the heterojunction bipolar transistor device having piezoelectric effect is prepared by the steps of: The specific temperature of the thermal oxidation in step (3) is 850-1000 ℃, and the thermal oxidation time is 10-30 min.

9. The method of claim 6, wherein the heterojunction bipolar transistor device having piezoelectric effect is prepared by the steps of: The sputtering power of the magnetron sputtering in step (5) is 180-300 W, and the sputtering time is 1-2 h.

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