CN110055502B

CN110055502B - Preparation method of semiconductor boron-carbon film with adjustable band gap

Info

Publication number: CN110055502B
Application number: CN201910374278.8A
Authority: CN
Inventors: 朱品文; 朱瑞; 陶强; 连敏; 董书山; 李志慧; 王欣; 崔田
Original assignee: Jilin University
Current assignee: Jilin University
Priority date: 2019-05-07
Filing date: 2019-05-07
Publication date: 2021-04-13
Anticipated expiration: 2039-05-07
Also published as: CN110055502A

Abstract

The invention discloses a preparation method of a semiconductor boron-carbon film with adjustable band gap, belonging to the technical field of amorphous semiconductor film material preparation. Glass is used as a substrate material on magnetron sputtering equipment, a high-purity boron target and a high-purity carbon target are used, the distance between the substrate and the target is 55mm, argon is used as working gas, under the working gas pressure of 1.0Pa, the power of the boron target is controlled to be changed from 160W to 240W, the power of the carbon target is controlled to be changed from 50W to 80W, the temperature of the substrate is controlled to be changed from 200 ℃ to 400 ℃, and magnetron sputtering is carried out, so that the semiconductor boron-carbon film with different band gaps is obtained. The invention utilizes the magnetron sputtering method, and effectively regulates and controls sp of carbon atoms in a-C: B by controlling the substrate temperature, the boron target power and the carbon target power²Hybrid states and sp³The proportion content of the hybrid state finally explores the E which can effectively regulate and control a-C: B_optThe method has important significance for further developing the applicable a-C.

Description

Preparation method of semiconductor boron-carbon film with adjustable band gap

Technical Field

The invention belongs to the technical field of amorphous semiconductor film material preparation, and particularly relates to a preparation method of a semiconductor boron-carbon film with adjustable band gap.

Background

The amorphous carbon thin films (a-C) have a wide optical band gap (E)_opt) The material is a potential novel semiconductor material and has wide application value in the aspects of electrical, mechanical, optical, thermal, chemical and thermal stability and the like. Such as excellent mechanical property, so that a-C is already applied to various wear-resistant coatings and lightsThe window learning device has wide application in the aspects of window learning, wear-resistant magnetic memory devices and the like; in the aspect of electricity, a-C can be used for preparing large-scale integrated circuits, solar cells and the like; in biomedicine, the a-C can be plated on an artificial material and implanted into a living body to promote the compatibility between the artificial material and the tissues of the living body. However, due to the disordered structure of a-C, E is regulated and controlled through experimental means_optIt is difficult. At present, a-C is changed into a semiconductor film with controllable band gap by doping element (B, N, P) mostly, and E is controlled by controlling the content of the doping element_optHowever, the content and distribution of the doping elements are difficult to control. Therefore, the method for controllably preparing the a-C with adjustable band gap is important to be explored.

In a-C, it is decided that E is_optThe essential origin of (A) is sp of a carbon atom²Hybrid state and sp³Proportional content of hybrid states, sp²Pi electrons in the hybrid state are important factors in providing carriers and forming a hopping conduction mechanism. Thus regulating sp²And sp³The proportion content of the hybrid state is an effective method for achieving adjustable a-C band gap. The E of a-C can be effectively adjusted by doping boron_optCurrently, the focus is mainly on the study of changing the boron content to regulate Eo_pt. But how to control E by changing experimental conditions_optNo report is found.

Disclosure of Invention

The technical problem to be solved by the invention is to overcome the defects of the background technology and adjust the A-C E by various modes by changing the deposition parameters of magnetron sputtering_opt. The film synthesized by the method has the advantages of high deposition rate, wide band gap adjustable range, repeatable experiment, simple instrument operation and lower cost.

The specific technical scheme of the invention is as follows.

A preparation method of a band gap adjustable semiconductor boron-carbon film is characterized in that on a magnetron sputtering device, glass is used as a substrate material, a boron target and a carbon target with the purity of 99.999% are used, the distance between the substrate and the target is 55mm, argon is used as working gas, under the working pressure of 1.0Pa, the power of the boron target is controlled to be changed from 160W to 240W, the power of the carbon target is controlled to be changed from 50W to 80W, and the temperature of the substrate is controlled to be changed from 200 ℃ to 400 ℃, and the semiconductor boron-carbon film with different band gaps is obtained through magnetron sputtering.

The preferred scheme of the invention is to maintain the working pressure of 1.0Pa and the substrate temperature of 200 ℃, control the carbon target power to be 50W, and control the boron target power to be 160W-240W, so as to obtain the semiconductor boron-carbon film with the band gap range of 3.19 eV-2.78 eV.

Another preferred scheme of the invention is to maintain the working pressure of 1.0Pa and the substrate temperature of 200 ℃, control the boron target power of 160W and the carbon target power to be changed between 50W and 80W, and obtain the semiconductor boron-carbon film with the band gap ranging from 3.19eV to 2.90 eV.

The experiments of the invention are all completed on JGP450 type radio frequency magnetron sputtering equipment, and the a-C: B with adjustable band gap is successfully prepared. The invention utilizes the magnetron sputtering method, and effectively regulates and controls the sp of carbon atoms in the boron-doped amorphous carbon film (a-C: B) by controlling the substrate temperature, the boron target power and the carbon target power²Hybrid states and sp³The proportion content of the hybrid state finally explores the E which can effectively regulate and control a-C: B_optThe method has important significance for further developing the applicable a-C.

Has the advantages that:

1. the invention realizes Eo of the semiconductor boron-carbon film by respectively changing the substrate temperature, the boron target power and the carbon target power_ptThe controllability is good.

2. The film prepared by the method has high deposition rate.

3. The invention takes cheap glass as a substrate to directly synthesize a-C: B, and the preparation method is simple.

Drawings

FIG. 1 is E of a-C: B prepared by varying boron target power in example 1_optFigure (a).

FIG. 2 is a graph of X-ray photoelectron spectroscopy measurements of a-C: B prepared by varying the boron target power in example 1.

FIG. 3 is E of a-C: B prepared by varying the carbon target power in example 2_optFigure (a).

FIG. 4 is a graph showing the temperature of a substrate changed in example 3Preparation of E of a-C: B_optFigure (a).

FIG. 5 is E of a-C: B prepared by varying the working air pressure in example 4_optFigure (a).

Detailed Description

Example 1

Glass is selected as a substrate material, the purity of a boron target and the purity of a carbon target are both 99.999 percent, the distance between the substrate and the target is both 55mm, and the working gas is argon. The power of the carbon target is fixed to be 50W; the substrate temperature is 200 ℃; the working air pressure is 1.0 Pa; controlling the power of the boron target to be 160W, 200W and 240W respectively, and carrying out magnetron sputtering on JGP450 type radio frequency magnetron sputtering equipment. E of the product prepared_optThe figure is shown in figure 1: e of the film with increasing boron target power_optVarying from 3.19eV to 2.78 eV. Therefore, the phenomenon that the band gap of the film is reduced in a monotonous way along with the increase of the target power proves that the E of the film can be effectively regulated and controlled by regulating and controlling the boron target power_optAnd has the advantage of wide regulation and control range.

The prepared sample was subjected to X-ray photoelectron spectroscopy, and the results are shown in fig. 2. When the boron target power was increased to 240W, a new peak 283.2eV (B-C) appeared, representing the boron atom build-up with the carbon atom, due to: as the boron target power is increased, the interaction of the doped boron with the carbon atoms is enhanced. And the peak position on the carbon atom is 284.1eV (sp) as the power of the boron target is increased²) And 284.9eV (sp)³) The area ratio of (A) to (B) is also increased, and the two peaks respectively represent sp of carbon atoms²Hybrid states and sp³The hybrid state. This indicates that increasing the boron target power can cause sp of carbon atoms in the film²The hybrid state increases. sp²The increase of the hybrid state is to make the thin film Eo_ptThe essential reason for the reduction.

Example 2

The fixed boron target power is 160W; regulating the power of the carbon target to be 50W, 60W and 80W respectively; the other conditions were the same as in example 1. Sample E thus obtained_optThe figure is shown in figure 3: e of the film with increasing carbon target power_optVarying from 3.19eV to 2.90 eV. Therefore, the E of the film can be effectively regulated and controlled by regulating and controlling the power of the carbon target_optAnd the regulation and control range is still larger.

Example 3

The same substrate, target material, target substrate distance, and working gas as in example 1 were used. Adjusting the substrate temperature to 200 ℃, 300 ℃ and 400 ℃ respectively; the working air pressure is 1.0 Pa; the boron target power is 160W; the carbon target power was 50W. E of the prepared sample_optAs shown in fig. 4. The results show that: e of the film with increasing substrate temperature_optIs gradually decreased, E_optThe regulation range of (A) is 3.19eV-3.15 eV. Thus E of the film can also be adjusted by adjusting the substrate temperature_optBut the band gap range of the adjustment is narrow.

Example 4

The same substrate, target material, target substrate distance, and working gas as in example 1 were used. Changing the working air pressure to 1.0Pa, 1.5Pa and 2.0 Pa; the substrate temperature is 200 ℃; the carbon target power is 50W; the boron target power was 160W. E of the prepared sample_optAs shown in FIG. 5, the E of the film changes with the change of the working air pressure_optThe law of decreasing first and increasing second appears, which shows that the effective control E that the working air pressure is difficult to monotonically increase or monotonically decrease_optA change in (c). This example is a counter example, used to compare the effects produced by the protocol of the present invention.

From the above examples, it can be seen that the deposition parameters of the present invention comprehensively affect E_optThe value needs to be considered comprehensively, wherein the most influential factor is the target power, and the target power is adjusted by E_optCan be controlled by a single adjustment and has a large control range, E_optThe value can be reduced from 3.19eV to 2.78 eV. The essential reason is that the sp in the film is caused along with the increase of the target power²Content of hybrid state, thereby E of the film_optAnd decreases.

Claims

1. A preparation method of a band gap adjustable semiconductor boron-carbon film is characterized in that on a magnetron sputtering device, glass is used as a substrate material, a boron target and a carbon target with the purity of 99.999% are used, the distance between the substrate and the target is 55mm, argon is used as working gas, under the working pressure of 1.0Pa, the power of the boron target is controlled to be changed from 160W to 240W, the power of the carbon target is controlled to be changed from 50W to 80W, and the temperature of the substrate is controlled to be changed from 200 ℃ to 400 ℃, and the semiconductor boron-carbon film with different band gaps is obtained through magnetron sputtering.

2. The method for preparing the semiconductor boron-carbon film with the adjustable band gap according to claim 1, wherein the working pressure of 1.0Pa and the substrate temperature of 200 ℃ are maintained, the carbon target power is controlled to be 50W, and the boron target power is controlled to be changed from 160W to 240W, so that the semiconductor boron-carbon film with the band gap ranging from 3.19eV to 2.78eV is obtained.

3. The method for preparing the semiconductor boron-carbon film with the adjustable band gap according to claim 1, wherein the working pressure of 1.0Pa and the substrate temperature of 200 ℃ are maintained, the boron target power is controlled to be 160W, and the carbon target power is changed from 50W to 80W, so that the semiconductor boron-carbon film with the band gap ranging from 3.19eV to 2.90eV is obtained.