CN102925866A

CN102925866A - Preparation technology for single-phase Mg2Si semiconductor film

Info

Publication number: CN102925866A
Application number: CN2012104558817A
Authority: CN
Inventors: 谢泉; 肖清泉; 余宏; 陈茜; 张晋敏
Original assignee: Guizhou University
Current assignee: Guizhou University
Priority date: 2012-11-14
Filing date: 2012-11-14
Publication date: 2013-02-13
Anticipated expiration: 2032-11-14
Also published as: CN102925866B

Abstract

The invention discloses a preparation technology for a single-phase Mg2Si semiconductor film. The preparation technology comprises processes as follows: 1, evaporating to deposit an Mg film on an Si substrate, wherein an Si sheet is cleaned and dried and then fixed on a sample frame above a resistance thermal evaporation chamber, and Mg particles are positioned in an evaporation crucible for vapor deposition; and 2, annealing: transferring an Si sheet carried out vapor deposition into a high vacuum annealing furnace for annealing under low-vacuum atmosphere, so as to obtain the single-phase Mg2Si semiconductor film. By adopting the preparation technology, the shortcomings that experimental conditions are severe, the cost is higher, the industrial popularization is hard to carry out and the like are overcome; and the problems that the quality of Mg2Si is finally influenced as impurities such as MgO oxide are generated when an electron beam evaporation and depositing technology is adopted and annealing is carried out under an argon atmosphere in the annealing process of an annealing furnace are solved.

Description

A kind of preparation technology of single-phase Mg2Si semiconductor film

Technical field

The present invention relates to a kind of single-phase Mg ₂The preparation technology of Si semiconductor film.

Background technology

Mg ₂Si has following characteristics as a kind of metal silicide environment-friendly semiconductor material that has good development prospect: the raw material resources of element M g, Si are abundant, earth's crust standing stock are large, cheap; The element nontoxic pollution-free, Mg ₂Si is corrosion-resistant, anti-oxidant.Environment-friendly semiconductor Mg ₂Why the Si material has broad application prospects, compatible mutually with existing Si base microelectronic technique such as its preparation method also because it has a series of good characteristics, has reduced the cost pressure that the production unit upgrading brings; 1.2-1.8 μ m infrared rays wave band is applicable to the modern communication device; With N-shaped Si good ohmic contact is arranged, contact resistivity is 2.2 * 10 ^-7Wcm is than the also little order of magnitude of metal A l.Simultaneously, Mg ₂Si is considered to the thermoelectric material of a kind of thermoelectrical efficiency high (ZT〉1).Aspect the research of photoelectricity and thermoelectric property, as a kind of narrow bandgap semiconductor material, Mg ₂Si has certain application prospect in field of infrared sensors, analyzes by the different elements that mix, and has proved Mg ₂Si has good thermoelectric material application prospect.In a word, Mg ₂The Si thin-film material has important application prospect in photoelectric device, electron device, energy devices field, and is poisonous or cause easily the semiconductor material of environmental pollution before being expected to progressively to replace, and has larger social benefit and environmental benefit.There have been at present multiple technologies to be applied to Mg ₂The preparation of Si thin-film material, comprising: pulsed laser deposition, molecular beam epitaxy, ionic fluid is synthetic etc., and these methods all exist experiment condition harsh, cost is higher, be difficult to the shortcomings such as industrialization promotion, adopt electron-beam evaporation technique, in annealing furnace, adopt argon atmosphere annealing in the annealing process, discovery has the generation of the impurity such as MgO oxide compound, finally affects Mg ₂The quality of Si.

Summary of the invention

The technical problem to be solved in the present invention: a kind of single-phase Mg is provided ₂The preparation technology of Si semiconductor film, the experiment condition harshness that exists to overcome prior art, cost is higher, is difficult to the shortcomings such as industrialization promotion, and adopts electron-beam evaporation technique, has the impurity such as MgO oxide compound, finally affects Mg ₂The problems such as the quality of Si.Technical solution of the present invention:

A kind of single-phase Mg ₂The preparation technology of Si semiconductor film, it comprises following process: the first, hydatogenesis Mg film on the Si substrate, at first with Si sheet cleaning-drying, the Si sheet is fixed on the specimen holder of resistance heat evaporator room top, the Mg particle is placed in the evaporator crucible, carries out evaporation; The second, annealing process, the Si sheet after evaporation is finished place high vacuum annealing furnace to carry out the annealing of rough vacuum atmosphere, prepare at last single-phase Mg ₂The Si semiconductor film.

In Si sheet cleaning-drying process, first the Si sheet is cut to the desired shape size, it with dehydrated alcohol, acetone ultrasonic cleaning, is re-used the deionized water ultrasonic cleaning; The sample that cleans up placed under 70 ℃ of conditions of loft drier dry.Use compressing tablet that the Si sheet is fixed on the specimen holder of resistance heat evaporator room top.

Before carrying out evaporation, first the resistance heat evaporator room is vacuumized, when vacuum tightness less than or equal to 2.0 * 10 ^-4During Pa, the beginning evaporation; Evaporation current progressively is added to 80 A, formally begins evaporation; The power of the resistance-type thermal evaporation during evaporation is 16～19 KW, and vaporator rate remains on 18-24 nm/min, and evaporation time is 15-18 min.

In the annealing process, the annealing furnace back end vacuum in the high vacuum annealing furnace is less than or equal to 10 ^-3Pa regulates angle valve before the annealing, make vacuum remain on 10 ^-1Pa-10 ^-2Between the Pa.

In the annealing process, annealing time 3-7 h, 350 ℃-450 ℃ of annealing temperatures.

Prepared single-phase Mg at the Si substrate ₂The Si semiconductor film, the Mg that namely prepares at the Si substrate ₂Do not contain other phase materials such as MgO or Mg crystal grain in the Si semiconductor film.

Beneficial effect of the present invention:

Adopt annealing way under the present invention-rough vacuum condition, prepared single-phase Mg ₂The Si semiconductor film, synthetic Mg ₂Do not contain the impurity such as MgO or Mg crystal grain in the Si film, be Mg ₂The device development and use of Si semiconductor film lay a good foundation.

The present invention adopts resistance-type thermal evaporation deposition and rough vacuum annealing technology, preparation single-phase Mg ₂The Si semiconductor film.The ultimate principle of resistance-type thermal evaporation deposition technique is, evaporating materials is put into suitable resistance heating body, and energising makes the evaporation of evaporating materials direct heating, forms film on the substrate thereby evaporating materials is deposited to gaseous form; The present invention at first adopts resistance-type evaporation technique deposition 280-480 nm pure metal Mg film on the Si monocrystal chip, forms the Si/Mg membrane structure, anneals with being placed in the vacuum annealing furnace.Annealing furnace back end vacuum is less than or equal to 10 ^-3Pa regulates angle valve before the annealing, make the back end vacuum remain on 10 ^-1Pa-10 ^-2Between the Pa; Annealing time 3-7 hour, 350 ℃-450 ℃ of annealing temperatures obtained single-phase Mg ₂The Si semiconductor film; Preparation technology of the present invention carries out anneal under the rough vacuum condition, avoided other gases such as oxygen to enter the single-phase Mg of preparation in the treating processes ₂The Si semiconductor film does not contain other phase impurity substances such as MgO or Mg crystal grain, and is same, if anneal under high vacuum condition, because metal M g is the high-vapor-pressure element, causes all or part of volatilization of metal M g, is unfavorable for that Si, Mg atomic diffusion are to form Mg ₂The Si film.Therefore the present invention adopts and carries out anneal under the rough vacuum condition, to obtain single-phase Mg ₂The Si semiconductor film, compared with prior art, it is lower that the present invention has a production cost, can carry out the advantage of suitability for industrialized production, and it is harsh to have solved the experiment condition that prior art exists, cost is higher, be difficult to the shortcomings such as industrialization promotion, and adopt electron-beam evaporation technique, in annealing furnace, adopt argon atmosphere annealing in the annealing process, the generation of the impurity such as MgO oxide compound is arranged, finally affect Mg ₂The problems such as the quality of Si, the present invention has prepared the single-phase Mg of impurity such as not containing MgO or Mg crystal grain ₂The Si semiconductor film is Mg ₂The device development and use of Si semiconductor film lay a good foundation.

Description of drawings

Fig. 1 is sample X-ray diffractogram of the present invention, is respectively the X-ray diffractogram of 3-7 h at 400 ℃ of annealing times;

Fig. 2 is Sample Scan Electronic Speculum figure of the present invention, is respectively the scanning electron microscope (SEM) photograph of 3 h at 400 ℃ of annealing times;

Fig. 3 is Sample Scan Electronic Speculum figure of the present invention, is respectively the scanning electron microscope (SEM) photograph of 4 h at 400 ℃ of annealing times;

Fig. 4 is Sample Scan Electronic Speculum figure of the present invention, is respectively the scanning electron microscope (SEM) photograph of 5 h at 400 ℃ of annealing times;

Fig. 5 is Sample Scan Electronic Speculum figure of the present invention, is respectively the scanning electron microscope (SEM) photograph of 6 h at 400 ℃ of annealing times;

Fig. 6 is Sample Scan Electronic Speculum figure of the present invention, is respectively the scanning electron microscope (SEM) photograph of 7 h at 400 ℃ of annealing times;

Fig. 7 is sample X-ray diffractogram of the present invention, at the X-ray diffractogram of 300-450 ℃ of annealing temperature 5 h.

Embodiment

Embodiment 1:

(1) will test with the Si sheet and cut to required size; At first, use respectively dehydrated alcohol, acetone ultrasonic oscillation 20 minutes, purpose is to remove the silicon chip surface organism, re-uses the deionized water ultrasonic cleaning 5 times, each 10 minutes; At last the sample that cleans up is placed under 70 ℃ of conditions of loft drier till the oven dry;

(2) test because area is less, uses shell fragment to be fixed on the specimen holder of deposited chamber top with the Si sheet.High-purity Mg particle directly is placed in the evaporator crucible;

(3) deposited chamber is vacuumized, when vacuum tightness less than or equal to 2.0 * 10 ^-4During Pa, and keep for some time;

(4) when vacuum tightness again less than or equal to 2.0 * 10 ^-4During Pa, heating current progressively is added to 80 A, the beginning evaporation; The power of the resistance-type thermal evaporation during evaporation is 18 KW, and vaporator rate remains on 18-24 nm/min, and evaporation time is 16 min;

(5) naturally cool to room temperature after evaporation is finished, take out and place high vacuum annealing furnace, annealing furnace back end vacuum is less than or equal to 10 ^-3Pa regulates angle valve before the annealing, make the back end vacuum remain on 10 ^-1Pa-10 ^-2Between the Pa.Annealing time 3-7 h, 400 ℃ of annealing temperatures form single-phase Mg ₂The Si semiconductor film.

Figure 2012104558817100002DEST_PATH_IMAGE001

Fig. 1 is the X-ray diffractogram of the sample of 400 ℃ of different annealing time preparations, and as seen, except the substrate Si diffraction peak, each diffraction peak is Mg among the figure ₂The Si diffraction peak, and with the PDF standard spectrum (card number: 65-9365) diffraction peak is corresponding one by one, illustrates under the preparation condition of the present invention, has prepared single-phase Mg ₂Si semiconductor film film.

Fig. 2 to Fig. 6 is the scanning electron microscope (SEM) photograph of the sample surface morphology of 400 ℃ of different annealing time preparations, and the result shows Mg ₂Si crystal grain is good to the sample surfaces coverage, and grain-size is larger, and the surface is comparatively smooth.Under the annealing conditions that experiment is adopted, the good Mg of crystalline state is arranged all ₂The Si film occurs.

Embodiment 2:

(1) will test with the Si sheet and cut to required size; At first, clean 20 min with dehydrated alcohol, acetone ultrasonic oscillation respectively, purpose is to remove the silicon chip surface organism, re-uses the deionized water ultrasonic oscillation and cleans each 10 min 5 times.The sample that cleans up is placed under 80 ℃ of conditions of loft drier at last and toast, till surperficial complete drying;

(2) test because area is less, uses shell fragment to be fixed on the specimen holder of deposited chamber top with the Si sheet.The Mg particle directly is placed in the evaporator crucible;

(4) when vacuum tightness again less than or equal to 2.0 * 10 ^-4During Pa, the beginning evaporation; Evaporation current progressively is added to 80 A, formally begins evaporation; The power of the resistance-type thermal evaporation during evaporation is 16～19KW, and vaporator rate remains on 18～24 nm/min, and evaporation time is 16 min;

(5) naturally cool to room temperature after evaporation is finished, take out again and place high vacuum annealing furnace.Annealing furnace back end vacuum is less than or equal to 10 ^-3Pa regulates angle valve before the annealing, make the back end vacuum remain on 10 ^-1Pa-10 ^-2Between the Pa.Annealing time 5h, prepares single-phase Mg by annealing temperature 350-450 ℃ ₂The Si semiconductor film.

Figure 2012104558817100002DEST_PATH_IMAGE003

Fig. 7 is that annealing time is 5 hours, the X-ray diffractogram of the sample that when different annealing temperature, prepares, and as seen, except the substrate Si diffraction peak, each diffraction peak is Mg among the figure ₂The Si diffraction peak, and with the PDF standard spectrum (card number: 65-9365) diffraction peak is corresponding one by one, illustrates under the preparation condition of the present invention, has prepared single-phase Mg ₂Si semiconductor film film.

Claims

1. single-phase Mg ₂The preparation technology of Si semiconductor film, it is characterized in that: it comprises following process: the first, hydatogenesis Mg film on the Si substrate at first with Si sheet cleaning-drying, is fixed on the Si sheet on the specimen holder of resistance heat evaporator room top, the Mg particle is placed in the evaporator crucible, carries out evaporation; The second, annealing process, the Si sheet after evaporation is finished place high vacuum annealing furnace to carry out the annealing of rough vacuum atmosphere, prepare at last single-phase Mg ₂The Si semiconductor film.

2. single-phase Mg according to claim 1 ₂The preparation technology of Si semiconductor film is characterized in that: in Si sheet cleaning-drying process, first the Si sheet is cut to the desired shape size, it with dehydrated alcohol, acetone ultrasonic cleaning, is re-used the deionized water ultrasonic cleaning; The sample that cleans up placed under 70 ℃ of conditions of loft drier dry, use compressing tablet that the Si sheet is fixed on the specimen holder of resistance heat evaporator room top.

3. single-phase Mg according to claim 1 ₂The preparation technology of Si semiconductor film is characterized in that: before carrying out evaporation, first the resistance heat evaporator room is vacuumized, when vacuum tightness less than or equal to 2.0 * 10 ^-4During Pa, the beginning evaporation; Evaporation current progressively is added to 80 A, formally begins evaporation; The power of the resistance-type thermal evaporation during evaporation is 16～19 KW, and vaporator rate remains on 18-24 nm/min, and evaporation time is 15-18 min.

4. single-phase Mg according to claim 1 ₂The preparation technology of Si semiconductor film is characterized in that: in the annealing process, the annealing furnace back end vacuum in the high vacuum annealing furnace is less than or equal to 10 ^-3Pa regulates angle valve before the annealing, make vacuum remain on 10 ^-1Pa-10 ^-2Between the Pa.

5. single-phase Mg according to claim 1 ₂The preparation technology of Si semiconductor film is characterized in that: in the annealing process, and annealing time 3-7 h, 350 ℃-450 ℃ of annealing temperatures.

6. single-phase Mg according to claim 1 ₂The preparation technology of Si semiconductor film is characterized in that: prepared single-phase Mg at the Si substrate ₂The Si semiconductor film, the Mg that namely prepares at the Si substrate ₂Do not contain other phase materials such as MgO or Mg crystal grain in the Si semiconductor film.