阅读说明：本技术 n型氮化硼薄膜/p型单晶硅异质pn结原型器件及制备方法 (N-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction prototype device and preparation method thereof ) 是由 殷红 刘彩云 李宇婧 高伟 于 2019-05-09 设计创作，主要内容包括：本发明提供了一种n型氮化硼薄膜/p型单晶硅异质pn结原型器件及制备方法,属于半导体材料领域。本发明采用磁控溅射方法在p型(100)面单晶硅基底上制备氮化硼薄膜；采用共溅射手段,在位碳掺杂得到n型氮化硼薄膜；然后在n型氮化硼薄膜一侧和p型单晶硅一侧分别制作银电极,即制得n型氮化硼薄膜/p型单晶硅异质pn结原型器件。本发明通过对氮化硼薄膜进行在位碳掺杂,得到电学性能优异的n型电导层,较比于未掺杂、硅掺杂的氮化硼薄膜的电学性能有显著提升；获得了整流特性良好的pn结原型器件。(The invention provides an n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction prototype device and a preparation method thereof, belonging to the field of semiconductor materials. The invention adopts a magnetron sputtering method to prepare a boron nitride film on a p-type (100) surface monocrystalline silicon substrate; adopting a co-sputtering method to dope in-situ carbon to obtain an n-type boron nitride film; then silver electrodes are respectively manufactured on one side of the n-type boron nitride film and one side of the p-type monocrystalline silicon, and the n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction prototype device is manufactured. According to the invention, the boron nitride film is subjected to in-situ carbon doping to obtain the n-type conductive layer with excellent electrical property, and the electrical property of the n-type conductive layer is obviously improved compared with that of the undoped silicon-doped boron nitride film; a pn junction prototype device having excellent rectifying characteristics is obtained.)

1. A preparation method of an n-type carbon-doped boron nitride film/p-type monocrystalline silicon heterogeneous pn junction prototype device is characterized by comprising the following steps:

(1) preparing a carbon-doped boron nitride film on a p-type monocrystalline silicon substrate by adopting a magnetron sputtering method; the thickness of the p-type monocrystalline silicon substrate is 100-500 mu m, the resistivity of the p-type monocrystalline silicon substrate is 1-5 omega cm, and the target material of magnetron sputtering is a carbon-containing hexagonal boron nitride target;

the magnetron sputtering method comprises the following steps:

pre-vacuumizing a magnetron sputtering chamber, and heating the p-type monocrystalline silicon substrate to 25-800 ℃;

continuously vacuumizing the magnetron sputtering chamber until reaching 1 × 10^-4～1×10^-5After Pa;

introducing 50-100 sccm argon and 0-50 sccm nitrogen into the magnetron sputtering chamber until the working pressure is 1-3 Pa;

applying negative bias of 0-200V to the p-type monocrystalline silicon substrate;

controlling the distance between the p-type monocrystalline silicon substrate and the target to be 4-8 cm;

setting the target sputtering power to be 80-200W and starting;

performing film sputtering for 30 min-3 h to prepare the carbon-doped boron nitride film; the thickness of the carbon-doped boron nitride film is 100-1000 nm, and the resistivity of the carbon-doped boron nitride film is 10^-4～10^-3Omega cm, the carbon doping concentration of the carbon-doped boron nitride film is 10¹⁸～10²⁰cm^-3Obtaining the n-type carbon-doped boron nitride film/p-type single crystalA silicon heterojunction pn junction;

(2) and respectively preparing Ag contact electrodes at two sides of the n-type carbon-doped boron nitride film/p-type monocrystalline silicon heterogeneous pn junction to obtain the n-type carbon-doped boron nitride film/p-type monocrystalline silicon heterogeneous pn junction prototype device.

2. The preparation method according to claim 1, wherein the p-type monocrystalline silicon substrate is heated to 100-600 ℃ after pre-vacuumizing a magnetron sputtering chamber.

3. The method according to claim 1, wherein after the evacuation, 50sccm of argon and 0 to 50sccm of nitrogen are introduced into the magnetron sputtering chamber to a working pressure of 1 to 3 Pa.

4. The preparation method of claim 1, wherein the negative bias of the p-type monocrystalline silicon substrate is between-100 and-150V after argon and nitrogen are introduced into the magnetron sputtering chamber to working pressure.

5. The preparation method according to claim 1, wherein after argon and nitrogen are introduced into the magnetron sputtering chamber to working pressure, the distance between the p-type single crystal silicon substrate and the target is controlled to be 6-8 cm.

6. The method according to claim 1, wherein after argon and nitrogen are introduced into the magnetron sputtering chamber to a working pressure, a target sputtering power of 120 to 150W is set and the sputtering is started.

7. The production method according to claim 1, wherein the thin film sputtering is performed for 2 hours.

8. The preparation method according to claim 1, wherein the p-type single crystal silicon substrate is sequentially subjected to ultrasonic cleaning in acetone, ethanol and deionized water, and then is blown dry by nitrogen.

9. The method of claim 1The n-type carbon-doped boron nitride film/p-type monocrystalline silicon heterogeneous pn junction prototype device prepared by the preparation method is characterized by comprising an n-type carbon-doped boron nitride film layer, a p-type monocrystalline silicon layer and Ag contact electrodes arranged at two sides of the n-type carbon-doped boron nitride film/p-type monocrystalline silicon heterogeneous pn junction, wherein a heterojunction is formed between the n-type carbon-doped boron nitride film layer and the p-type monocrystalline silicon layer, and the n-type carbon-doped boron nitride film layer is formed by magnetron sputtering of a carbon-containing hexagonal boron nitride target; the thickness of the p-type monocrystalline silicon layer is 100-500 mu m, the resistivity of the p-type monocrystalline silicon layer is 1-5 omega cm, the thickness of the n-type carbon-doped boron nitride thin film layer is 100-1000 nm, and the doping concentration of carbon in the n-type carbon-doped boron nitride thin film layer is 10¹⁸～10²⁰cm^-3The resistivity of the n-type carbon-doped boron nitride film layer is 10^-4～10^-3Ωcm。

10. Use of an n-type boron nitride film/p-type single crystal silicon hetero-pn junction prototype device according to claim 9 in the field of semiconductor devices.

Technical Field

The invention relates to the field of semiconductor materials, in particular to an n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction prototype device and a preparation method thereof.

Background

With the development of material science and the progress of semiconductor technology, the performance of silicon-based semiconductor devices has gradually reached the limit of silicon material theory, and the development of industry, science and technology and military continuously puts more rigorous requirements on semiconductor devices, and it has become urgent to develop novel materials with the characteristics of high strength, high hardness, high temperature resistance, high frequency, radiation resistance, corrosion resistance and the like.

The wide-bandgap semiconductor material has many characteristics of high hardness, good chemical stability, high thermal conductivity, high breakdown field strength, high saturation drift velocity, small dielectric constant, capability of emitting and detecting short-wavelength light reaching deep ultraviolet, and the like, is an ideal material for meeting the development requirements of industrial semiconductor devices, and is called as a third-generation semiconductor. Particularly, boron nitride is the simplest material in the III-V compound semiconductor, has an ultra-wide band gap (5.9 eV for hexagonal boron nitride; 6.4eV for cubic boron nitride), extreme physicochemical properties, excellent semiconductor and photoelectric properties and the like, and has unique advantages in the fields of military affairs, aviation, industry and the like.

International research on pn-junctions based on boron nitride materials is still in its infancy. Most of the existing reports on pn junctions are boron nitride bulk single crystals synthesized at high temperature and high pressure, which cannot be directly deposited on a substrate and are not beneficial to being applied to large-scale and large-area integrated circuits. In addition, reports on the synthesis and efficient doping of high quality boron nitride films are also very limited. The growth window of the boron nitride film is very narrow, and particularly the growth repeatability of the high-quality boron nitride film is very poor, the deposition means is different, the process parameters are completely different, and the same is true of expensive and precise equipment. At the same time, it is difficult to achieve efficient doping with high concentration and low compensation due to the forbidden bandwidth of boron nitride. Therefore, research on the application of high-quality boron nitride thin films to the related fields such as semiconductors is slow.

The invention adopts a magnetron sputtering method, grows an n-type boron nitride film on a p-type monocrystalline silicon substrate by in-situ carbon doping, improves the semiconductor characteristics of the boron nitride film such as conductivity, doping rate, mobility and the like by adjusting co-sputtering parameters, obtains an n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction prototype device with high rectification performance and a preparation method thereof, and provides important basis for the application of the high-quality boron nitride film in the fields of semiconductors, electronic industry and the like.

Disclosure of Invention

The invention aims to provide an n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction prototype device and a preparation method thereof.

The technical scheme adopted by the invention is as follows:

an n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction prototype device and a preparation method thereof are characterized in that the method comprises the following steps: (1) preparing a carbon-doped boron nitride film on a p-type monocrystalline silicon substrate by adopting a magnetron sputtering method; (2) ohmic electrodes are respectively prepared on two sides of the n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction, and the n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction prototype device is prepared.

The magnetron sputtering device can be commercially available or built by itself.

The target material of the magnetron sputtering in the step (2) is a carbon-containing hexagonal boron nitride target, or the hexagonal boron nitride and the carbon simple substance are respectively used as target materials and double-target co-sputtering is adopted. Preferably a hexagonal boron nitride target containing carbon.

The magnetron sputtering method in the step (1) is carried out according to the following steps: pre-vacuumizing a magnetron sputtering chamber, and heating a substrate to 25-800 ℃, preferably 100-600 ℃; continuing to vacuumize until reaching 1X 10^-4～1×10^-5Pa, preferably 10^-5Pa; introducing 50-100 sccm argon gas and 0-50 sccm nitrogen gas to the working pressure of 1-3 Pa, preferably 50sccm argon gas and 0-50 sccm nitrogen gas; applying a substrate negative bias voltage of 0 to-200V, preferably-100 to-150V; controlling the distance between the substrate and the target to be 4-8 cm, preferably 6-8 cm; setting target sputtering power of 80-200W and starting, preferably 120-150W; sputtering the film for 30 min-3 h to obtain the carbon-doped boron nitride film with the thickness of 100-1000 nm and the doping concentration of 10¹⁸～10²⁰cm^-3Thus obtaining the n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction.

In the step (2), ohmic electrodes are prepared on two sides of the n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction, and a conventional electrode preparation method can be used, which is a technology well known to those skilled in the art.

The invention also provides the n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction prepared by the method.

The n-type boron nitride thin film layer provided by the invention has the semiconductor characteristics of higher conductivity, doping rate, mobility and the like, and further the n-type boron nitride thin film/p-type monocrystalline silicon heterogeneous pn junction has good rectification performance.

The invention provides an application of the n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction in the field of semiconductor devices and the like.

The invention has the following beneficial effects:

(1) according to the invention, the high-quality n-type boron nitride film grows on the p-type monocrystalline silicon substrate in an in-situ carbon doping manner, the growth quality and doping quality of the boron nitride film can be improved simultaneously by adjusting growth parameters, the defects of high sample defect density, high compensation, low doping efficiency and the like generally caused by non-in-situ doping means such as ion implantation and the like are overcome, and a carbon simple substance is effectively doped into the boron nitride substrate, so that important semiconductor performance parameters such as doping efficiency, mobility, conductivity and the like of the boron nitride film are improved.

(2) The invention adopts the magnetron sputtering method, and can prepare large-area uniform and compact boron nitride films. The method has the advantages of low cost, controllable technical process, convenient operation and easy industrial popularization.

(3) The invention overcomes the high intrinsic resistance of the boron nitride film by effectively doping the boron nitride film, widens the application of the boron nitride film in the field of semiconductor devices, which can only be used as an insulating layer, a protective layer and the like of an integrated circuit, and converts the boron nitride film to a semiconductor functional material with high reliability and high performance.

(4) The n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction prototype device with good rectification performance has higher breakdown voltage and working voltage, lower leakage current and higher rectification ratio, and provides scientific basis and technical support for the boron nitride film in the potential application field of wide bandgap semiconductors.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application.

FIG. 1 is a SEM photograph of a boron nitride film obtained in example 1 of the present invention;

FIG. 2 is a SEM photograph of a boron nitride film obtained in example 2 of the present invention;

FIG. 3 is a SEM photograph of a boron nitride film obtained in example 3 of the present invention;

FIG. 4 is a SEM photograph of a boron nitride film obtained in example 4 of the present invention;

FIG. 5 is a Fourier infrared transform spectrum of a boron nitride film obtained in examples 1 to 4 of the present invention;

FIG. 6 is an I-V curve diagram of an n-type boron nitride film/p-type silicon heterojunction prepared in embodiments 1-4 of the present invention at room temperature.

Detailed Description

The present invention will be further clearly and completely described in the following detailed description, taken in conjunction with the accompanying drawings, although the scope of the invention is not limited thereto.

Example 1

Ultrasonic cleaning p-type silicon (100) single chip cut according to required size in acetone, ethanol and deionized water, blow-drying with nitrogen, placing on sample rack, sending into vacuum deposition chamber, and pumping to 3 × 10 vacuum degree in the deposition chamber^-5Pa, heating the substrate to 500 ℃; continuing to vacuumize until the back bottom vacuum of the deposition chamber reaches 3 x 10^-5When Pa, introducing a reaction working gas argon gas of 50sccm to a working pressure of 2 Pa; the distance between the substrate and the target is 8cm, substrate negative bias voltage-150V is added, the sputtering power of the target is set to be 150W, then the glow is started, after the pre-sputtering is carried out for 2min, the baffle is moved away, the film sputtering is carried out, the film sputtering time is 2h, and the n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction is obtained. Silver electrodes are respectively prepared on two sides of the heterogeneous pn junction of the n-type boron nitride film/p-type monocrystalline silicon to form ohmic contact, namely the n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction prototype device is prepared, and an I-V curve of the device is obtained by adopting a semiconductor test system.

FIG. 1 is a scanning electron micrograph of the boron nitride film obtained in example 1, showing that the film has a dense, flat and uniform surface. FIG. 5 is an infrared spectrum of the boron nitride thin film prepared in examples 1 to 4, wherein the boron nitride thin film prepared in example 1 is 770cm^-1Is a characteristic peak of B-N at 923cm^-1Is characterized by C-N characteristic peak at 1100cm^-1Is a C-B characteristic peak at 1239cm^-1The peak is a characteristic B-O peak. The boron nitride film is an n-type semiconductor with a doping concentration of 10 measured by a HL5500 Hall test system²⁰cm^-3Mobility of 5.29cm²Vs, resistivity of 4.1X 10^-3Omega cm. FIG. 6 is an I-V curve diagram of the n-type boron nitride film/p-type silicon heterojunction prepared in examples 1-4 at room temperature. The test results show that the heterojunction prepared in example 1 has a rectification rate of about 115 at + -5V and a reverse leakage current of about 7X 10 at room temperature^-8A, has obvious rectification characteristic. Within the maximum voltage range of +/-10VHere, the maximum rectification rate at saturation is still not obtained, but the forward current is far from saturation from the trend, i.e. the actual rectification rate of the pn junction should be higher and the breakdown voltage greater than 10V.

Example 2

Ultrasonic cleaning p-type silicon (100) single chip cut according to required size in acetone, ethanol and deionized water, blow-drying with nitrogen, placing on sample rack, sending into vacuum deposition chamber, and pumping to 3 × 10 vacuum degree in the deposition chamber^-5Pa, heating the substrate to 500 ℃; continuing to vacuumize until the back bottom vacuum of the deposition chamber reaches 3 x 10^-5When Pa, introducing 50sccm of reaction working gas argon and 20sccm of nitrogen into the reactor until the working pressure is 2 Pa; the distance between the substrate and the target is 8cm, substrate negative bias voltage-150V is added, the sputtering power of the target is set to be 150W, then the glow is started, after the pre-sputtering is carried out for 2min, the baffle is moved away, the film sputtering is carried out, the film sputtering time is 2h, and the n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction is obtained. Silver electrodes are respectively prepared on two sides of the n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction to form ohmic contact, namely the n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction prototype device is prepared, and a semiconductor test system is adopted to obtain an I-V curve of the device.

FIG. 2 is a scanning electron micrograph of the boron nitride film obtained in example 2, showing that the film is dense, flat and uniform in particle size. FIG. 5 is an infrared spectrum of the boron nitride film obtained in examples 1 to 4, wherein the boron nitride film obtained in example 2 is 774cm^-1Is a characteristic peak of B-N at 923cm^-1Is a C-N characteristic peak at 1104cm^-1Is characterized by a C-B characteristic peak at 1251cm^-1The peak is a characteristic B-O peak. The boron nitride film is an n-type semiconductor with a doping concentration of 10 measured by a HL5500 Hall test system¹⁹cm^-3Mobility of 214.33cm²Vs, resistivity of 2.12X 10^-3Omega cm. FIG. 6 is an I-V curve diagram of the n-type boron nitride film/p-type silicon heterojunction prepared in examples 1-4 at room temperature. The test results show that the rectification rate of the heterogeneous pn junction prepared in example 2 at the position of +/-5V is about 21.5 at room temperature, and the reverse leakage current is about 2.7 multiplied by 10^-6A, has obvious rectification characteristic. At the maximum voltage range of about + -10V, the voltage is not yet measuredThe maximum rectification rate at saturation is obtained, but the forward current is far from saturation from the trend, i.e. the actual rectification rate of the pn junction is higher and the breakdown voltage is greater than 10V.

Example 3

Ultrasonic cleaning p-type silicon (100) single chip cut according to required size in acetone, ethanol and deionized water, blow-drying with nitrogen, placing on sample rack, sending into vacuum deposition chamber, and pumping to 3 × 10 vacuum degree in the deposition chamber^-5Pa, heating the substrate to 500 ℃; continuing to vacuumize until the back bottom vacuum of the deposition chamber reaches 3 x 10^-5When Pa, introducing reaction working gas argon of 50sccm and nitrogen of 40sccm to working pressure of 2 Pa; the distance between the substrate and the target is 8cm, substrate negative bias voltage-150V is added, the sputtering power of the target is set to be 150W, then the glow is started, after the pre-sputtering is carried out for 2min, the baffle is moved away, the film sputtering is carried out, the film sputtering time is 2h, and the n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction is obtained. Silver electrodes are respectively prepared on two sides of the n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction to form ohmic contact, namely the n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction prototype device is prepared, and a semiconductor test system is adopted to obtain an I-V curve of the device.

FIG. 3 is a scanning electron micrograph of the boron nitride film obtained in example 3, showing that the film has a dense, flat surface and uniform particles. FIG. 5 is an infrared spectrum of the boron nitride film obtained in examples 1 to 4, wherein the boron nitride film obtained in example 3 is 774cm^-1Is a characteristic peak of B-N at 936cm^-1Is characterized by a C-N characteristic peak, 1107cm^-1Is characterized by a C-B characteristic peak at 1251cm^-1The peak is a characteristic B-O peak. The boron nitride film is an n-type semiconductor with a doping concentration of 10 measured by a HL5500 Hall test system¹⁹cm^-3Mobility of 214cm²Vs, resistivity of 2.08X 10^-3Omega cm. FIG. 6 is an I-V curve diagram of the n-type boron nitride film/p-type silicon heterojunction prepared in examples 1-4 at room temperature. The test results showed that the heterojunction prepared in example 3 has a rectification ratio of about 12.3 at + -5V and a reverse leakage current of about 8.1 × 10 at room temperature^-6A, has obvious rectification characteristic. At a maximum voltage range of about + -10V, saturation is not obtained yetThe maximum rectification rate of time, but the forward current is far from saturation from the trend, i.e. the actual rectification rate of the pn junction is higher and the breakdown voltage is greater than 10V.

Example 4

Ultrasonic cleaning p-type silicon (100) single chip cut according to required size in acetone, ethanol and deionized water, blow-drying with nitrogen, placing on sample rack, sending into vacuum deposition chamber, and pumping to 3 × 10 vacuum degree in the deposition chamber^-5Pa, heating the substrate to 500 ℃; continuing to vacuumize until the back bottom vacuum of the deposition chamber reaches 3 x 10^-5When Pa, introducing reaction working gases of 50sccm of argon and 50sccm of nitrogen until the working pressure is 2 Pa; the distance between the substrate and the target is 8cm, substrate negative bias voltage-150V is added, the sputtering power of the target is set to be 150W, then the glow is started, after the pre-sputtering is carried out for 2min, the baffle is moved away, the film sputtering is carried out, the film sputtering time is 2h, and the n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction is obtained. Silver electrodes are respectively prepared on two sides of the n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction to form ohmic contact, namely the n-type boron nitride film/p-type monocrystalline silicon heterogeneous pn junction prototype device is prepared, and a semiconductor test system is adopted to obtain an I-V curve of the device.

FIG. 4 is a scanning electron micrograph of the boron nitride film obtained in example 4 showing that the film has a dense, flat and uniform surface. FIG. 5 is an infrared spectrum of the boron nitride films obtained in examples 1 to 4, wherein the boron nitride film obtained in example 4 is 776cm^-1Is a characteristic peak of B-N at 932cm^-1Is a C-N characteristic peak at 1104cm^-1Is characterized by a C-B characteristic peak at 1251cm^-1The peak is a characteristic B-O peak. The boron nitride film is an n-type semiconductor with a doping concentration of 10 measured by a HL5500 Hall test system¹⁹cm^-3Mobility of 193.67cm²Vs, resistivity of 2.1X 10^-3Omega cm. FIG. 6 is an I-V curve diagram of the n-type boron nitride film/p-type silicon heterojunction prepared in examples 1-4 at room temperature. The test results showed that the heterojunction prepared in example 4 has a rectification ratio of about 3 at + -5V and a reverse leakage current of about 1.6X 10 at room temperature^-5A, has obvious rectification characteristic. At the maximum voltage range of about +/-10V, the maximum integral of the saturation is not obtainedThe flow rate, but from the trend the forward current is far from saturation, i.e. the actual rectification rate of the pn junction is higher and the breakdown voltage is larger than 10V.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.