阅读说明：本技术 硅基iv族合金材料及其外延方法 (Silicon-based group IV alloy material and epitaxial method thereof ) 是由 刘香全 郑军 成步文 于 2019-11-05 设计创作，主要内容包括：一种硅基IV族合金材料及其外延方法,该外延方法包括以下步骤：步骤1：将衬底送入高真空的生长腔室,进行脱氢脱氧处理；步骤2：调节衬底温度；步骤3：在衬底上至少共同沉积Ge、Sn和Pb原子,完成材料外延。本发明的锗锡铅合金材料可实现直接带隙,并且与硅基CMOS工艺兼容；制备的锗锡铅合金材料晶体质量良好,相比同组分的锗锡或锗铅材料具有更窄的带隙；为硅基发光和探测器件的制作提供一种新型材料,在望在硅基光电子领域发挥重大的作用。(A silicon-based IV-group alloy material and an epitaxial method thereof are disclosed, wherein the epitaxial method comprises the following steps: step 1: delivering the substrate into a high-vacuum growth chamber for dehydrogenation and deoxidation treatment; step 2: adjusting the temperature of the substrate; and step 3: and co-depositing at least Ge, Sn and Pb atoms on the substrate to complete the material epitaxy. The germanium tin lead alloy material can realize direct band gap and is compatible with a silicon-based CMOS (complementary metal oxide semiconductor) process; the prepared germanium tin lead alloy material has good crystal quality, and has narrower band gap compared with the germanium tin or germanium lead material with the same component; provides a novel material for manufacturing silicon-based luminescent and detecting devices, and is expected to play an important role in the field of silicon-based photoelectronics.)

1. A method for epitaxy of silicon-based group IV alloy materials, comprising the steps of:

step 1: delivering the substrate into a high-vacuum growth chamber for dehydrogenation and deoxidation treatment;

step 2: adjusting the temperature of the substrate;

and step 3: and co-depositing at least Ge, Sn and Pb atoms on the substrate to complete the material epitaxy.

2. Epitaxy method according to claim 1, characterised in that step 1 is preceded by a step of washing;

and the final step of the cleaning step is to carry out surface treatment by using diluted hydrofluoric acid to realize surface hydrogen passivation.

3. Epitaxial method according to claim 1, characterized in that the temperature of the dehydrodeoxygenation in step 1 is between 500 ℃ and 1100 ℃ for a time comprised between 5 and 25 min.

4. Epitaxial method according to claim 2, characterized in that the substrate temperature in step 2 is between 120 ℃ and 350 ℃.

5. The epitaxy method according to claim 1, characterised in that in step 2 the substrate is a silicon substrate, a germanium substrate or a germanium dummy substrate on silicon.

6. The epitaxy method according to claim 1, characterised in that the substrate crystal orientation in step 2 is (100), (110) or (111).

7. Epitaxy method according to claim 1, characterised in that in step 3, the Ge, Sn, Pb atoms are co-deposited on the substrate by physical vapour deposition or chemical vapour deposition.

8. A silicon-based group IV alloy material prepared by the epitaxial method of any one of claims 1 to 7.

9. The silicon-based group IV alloy material according to claim 8, wherein the band gap is adjusted in the range of 0-0.66eV by adjusting the composition of Ge, Sn, Pb atoms co-deposited on the substrate in step 4.

10. The silicon-based group IV alloy material of claim 8, wherein the silicon-based group IV alloy material is a direct bandgap material.

Technical Field

The invention belongs to the technical field of silicon-based photoelectric materials, and mainly relates to a silicon-based IV-group alloy material and an epitaxial method thereof.

Background

The realization of silicon-based photoelectric integration is an important means for solving the problems of power consumption, time delay, I/O and the like of the traditional electric interconnection. The direct band gap semiconductor material compatible with silicon is searched, and the silicon-based high-efficiency light source is realized, so that the direct band gap semiconductor material has great significance and application value. At present, the photoelectric materials which can realize silicon-based compatibility are mainly group IV materials, and germanium tin and germanium lead alloys can realize direct band gap conversion by adjusting the components of Sn and Pb.

Studies have shown that germanium tin requires more than 8% of the Sn component for conversion to the direct bandgap, while germanium lead requires about 3.4% Pb. In the epitaxy of germanium tin and germanium lead, the following difficulties need to be overcome: 1) sn or Pb has larger lattice mismatch with Ge; 2) lower equilibrium solid solubility of Sn or Pb in Ge; 3) sn or Pb has lower surface free energy and is easy to form surface segregation and segregation phenomena. Therefore, it is difficult to extend high-composition and high-quality germanium tin and germanium lead alloys, and the requirement for manufacturing high-efficiency silicon-based light-emitting devices cannot be met.

Disclosure of Invention

It is therefore an objective of the claimed invention to provide a silicon-based group IV alloy material and an epitaxy method thereof, which are aimed at least partially solving at least one of the above-mentioned problems.

In order to achieve the above object, the present invention provides a method for epitaxy of silicon-based group IV alloy material, comprising the steps of:

step 1: delivering the substrate into a high-vacuum growth chamber for dehydrogenation and deoxidation treatment;

step 2: adjusting the temperature of the substrate;

and step 3: and co-depositing at least Ge, Sn and Pb atoms on the substrate to complete the material epitaxy.

Wherein, step 1 also includes the step of washing before;

and the final step of the cleaning step is to carry out surface treatment by using diluted hydrofluoric acid to realize surface hydrogen passivation.

Wherein, the temperature of the dehydrogenation and deoxidation in the step 1 is between 500 and 1100 ℃, and the time is 5 to 25 min.

Wherein the substrate temperature in the step 2 is 120-350 ℃.

And 2, the substrate in the step 2 is a silicon substrate, a germanium substrate or a germanium dummy substrate on silicon.

Wherein the substrate crystal orientation in step 2 is (100), (110) or (111).

In step 3, Ge, Sn and Pb atoms are co-deposited on the substrate by adopting a physical vapor deposition or chemical vapor deposition method.

A silicon-based group IV alloy material prepared according to the epitaxial method as described above.

The purpose of adjusting the band gap is achieved by regulating and controlling the components of Ge, Sn and Pb atoms which are co-deposited on the substrate in the step 4, and the adjustment range of the band gap is 0-0.66 eV.

Wherein the silicon-based group IV alloy material is a direct bandgap material.

Based on the technical scheme, compared with the prior art, the silicon-based IV-group alloy material and the epitaxial method thereof have at least one of the following beneficial effects:

(1) the germanium tin lead alloy material can realize direct band gap and is compatible with a silicon-based CMOS (complementary metal oxide semiconductor) process;

(2) the prepared germanium tin lead alloy material has good crystal quality, and has narrower band gap compared with the germanium tin or germanium lead material with the same component;

(3) provides a novel material for manufacturing silicon-based luminescent and detecting devices, and is expected to play an important role in the field of silicon-based photoelectronics.

Drawings

FIG. 1 is a schematic diagram of the band transition of germanium tin lead in the present invention;

FIG. 2 shows Rutherford Backscattering (RBS) random spectra of a Ge-Sn-Pb single crystal film with certain epitaxial composition in example 1 of the present invention;

FIG. 3 is an Atomic Force Microscope (AFM) view of a single crystal thin film of germanium tin lead with certain epitaxy composition in example 1 of the present invention;

FIG. 4 is an X-ray diffraction (XRD) pattern of a germanium tin lead single crystal film of certain epitaxial composition in example 1 of the present invention;

fig. 5 is an X-ray diffraction (XRD) pattern of a ge-sn-pb single crystal film of certain epitaxial composition in example 2 of the present invention.

Detailed Description

The main principle that germanium tin or germanium lead alloy can realize direct band gap conversion is as follows: after Sn or Pb element is introduced into Ge, the descending speed of gamma energy valley (direct band gap) is larger than that of L energy valley (indirect band gap). In view of the same mechanism that germanium tin and germanium lead alloy are converted into direct band gaps, Sn and Pb elements can be simultaneously introduced into Ge, theoretically, Sn and Pb can be simultaneously dissolved in crystal lattices of Ge through a non-equilibrium epitaxial means, a direct band gap material can be formed through the combined action of Sn and Pb atoms, and the formed novel germanium tin lead alloy is expected to become a new generation of silicon-based compatible photoelectric material.

The invention discloses a novel silicon-based IV-group alloy material and a preparation method thereof, wherein the material is germanium tin lead (Ge) _{1-x- y}Sn _xPb _y) The alloy material can realize direct band gap and has the characteristic of silicon-based compatibility. The epitaxial method comprises the following steps: step 1), taking a substrate, cleaning and reserving for later use; step 2) rapidly conveying the substrate into a high-vacuum growth chamber, and then carrying out dehydrogenation and deoxidation treatment; step 3) adjusting the temperature of the substrate; and 4) depositing Ge, Sn and Pb atoms on the substrate together to finish the epitaxial preparation of the material. The germanium tin lead alloy material provided by the invention has great application prospects in the aspects of manufacturing silicon-based light sources, detection devices and the like.

Specifically, the invention provides an epitaxial method of a silicon-based IV-group alloy material, which comprises the following steps:

step 1: delivering the substrate into a high-vacuum growth chamber for dehydrogenation and deoxidation treatment;

step 2: adjusting the temperature of the substrate;

and step 3: and co-depositing at least Ge, Sn and Pb atoms on the substrate to complete the material epitaxy.

Wherein, step 1 also includes the step of washing before;

and the final step of the cleaning step is to carry out surface treatment by using diluted hydrofluoric acid to realize surface hydrogen passivation.

Wherein, the temperature of the dehydrogenation and deoxidation in the step 1 is between 500 and 1100 ℃, and the time is 5 to 25 min.

Wherein the substrate temperature in the step 2 is 120-350 ℃.

And 2, the substrate in the step 2 is a silicon substrate, a germanium substrate or a germanium dummy substrate on silicon.

Wherein the substrate crystal orientation in step 2 is (100), (110) or (111).

In step 3, Ge, Sn and Pb atoms are co-deposited on the substrate by adopting a physical vapor deposition or chemical vapor deposition method.

A silicon-based group IV alloy material prepared according to the epitaxial method as described above.

The purpose of adjusting the band gap is achieved by regulating and controlling the components of Ge, Sn and Pb atoms which are co-deposited on the substrate in the step 4, and the adjustment range of the band gap is 0-0.66 eV.

Wherein the silicon-based group IV alloy material is a direct bandgap material.

In order that the objects, technical solutions and advantages of the present invention will become more apparent, the present invention will be further described in detail with reference to the accompanying drawings in conjunction with the following specific embodiments.

Referring to fig. 1, the present invention provides a novel silicon-based group IV alloy material, named germanium-tin-lead alloy, which can realize direct band gap, is compatible with silicon-based CMOS process, and is expected to play an important role in the field of silicon-based photoelectrons. The principle of achieving a direct bandgap is as follows:

sn and Pb atoms are introduced into Ge, so that the descending speed of a gamma energy valley (direct band gap) is higher than that of an L energy valley (indirect band gap), and the material becomes a direct band gap material.

The invention also provides an epitaxial method of the germanium tin lead alloy material, which comprises the following steps:

step 1: and taking the substrate and cleaning the substrate. The substrate cleaning is carried out by sequentially carrying out ultrasonic cleaning by using acetone, alcohol and deionized water, and finally carrying out surface treatment by using diluted HF (hydrogen fluoride), so that after germanium oxide on the surface is removed, a germanium dangling bond on the surface is bonded with hydrogen, and the surface hydrogen passivation is realized.

Step 2: and (3) rapidly conveying the substrate into a high-vacuum growth chamber, and then carrying out dehydrogenation and deoxidation treatment, wherein the temperature during dehydrogenation and deoxidation is 500-1000 ℃ and the time is 5-25 min. The sample transfer process is fast and uses higher temperatures due to the limited ability of hydrogen passivation to prevent oxidation of the substrate. The purpose of dehydrogenation and deoxidation is to expose a clean substrate surface, which is beneficial to the epitaxial growth of high-quality germanium-tin-lead alloy.

And step 3: the temperature of the substrate is adjusted to be about 120-350 ℃. The substrate temperature is not too high or too low, and the material surface segregation is easily caused by too high temperature; too low will not provide enough kinetic energy to render the epitaxial material amorphous.

And 4, step 4: and (4) co-depositing Ge, Sn and Pb atoms on the substrate to complete material epitaxy. The epitaxial method can adopt molecular beam epitaxy, magnetron sputtering, electron beam evaporation or chemical vapor deposition.