CN115627525A - Graphite boat - Google Patents

Abstract

The invention discloses a graphite boat, which is characterized in that a plurality of swing arms are arranged on the outer side of the graphite boat, and the movement of the swing arms is driven by the movement of the graphite boat, so that the growth solution is fully stirred, the component uniformity of the growth solution is improved, an epitaxial film with uniform components is finally obtained, and the problem that the existing epitaxial film with better effect cannot be repeatedly obtained by the graphite boat is effectively solved.

Description

a graphite boat

technical field

The invention relates to the technical field of materials, in particular to a graphite boat.

Background technique

The vertical liquid phase epitaxy process generally uses a larger crucible, in which a large amount of growth solution is placed, the growth solution is completely melted at high temperature during the epitaxial growth process, the graphite boat is immersed in the growth solution and swings, and the balance of the solid-liquid phase is changed by adjusting the temperature state, and then by controlling the cooling rate to slowly cool down, the film is crystallized and grown on the surface of the substrate immersed in the solution. During the whole liquid phase epitaxial growth process, the substrate is loaded in the graphite boat, the graphite boat is immersed in the growth solution, and the growth of the epitaxial film is realized through the relative movement of the graphite boat.

During the epitaxial growth process, the uniformity of the components of the growth solution will directly determine the uniformity of the components of the epitaxial film. The graphite boat is immersed in the growth solution, and the segregation of the growth solution components can be reduced by the swing of the graphite boat to make the components more uniform. Improve the consistency of the vertical liquid phase epitaxy process.

At present, in the vertical liquid phase epitaxy process, the agitation of the graphite boat is relied on to improve the component uniformity of the growth solution. The size of the graphite boat is fixed during processing, so the agitation of the growth solution by the graphite boat is limited. It is an urgent problem to be solved to realize the repeatable vertical liquid phase epitaxy single crystal thin film preparation with stable quality under the conditions (vertical liquid phase epitaxy process parameters, growth solution formula, etc.).

Contents of the invention

The invention provides a graphite boat to solve the problem in the prior art that the vertical liquid phase epitaxy single crystal thin film cannot be repeatedly prepared well.

The invention provides a graphite boat, an inner boat, an outer boat, and a plurality of swing arms arranged on the outer boat; the swing arms are arranged above the growth groove of the outer boat, and a plurality of the swing arms Uniformly distributed on the periphery of the outer boat, the swing arm is used to stir the growth solution driven by the graphite boat, so as to increase the stirring effect on the growth solution, so that the component uniformity of the growth solution is improved, Finally, an epitaxial film with uniform composition is obtained.

Optionally, the swing arm is fixed on the side wall of the outer boat by plugging.

Optionally, the swing arm is Z-shaped, and the swing arm includes a fixing part, a connecting part and a stirring part;

The fixing part is used to fix the swing arm on the outer side wall of the outer boat;

The connecting part is used to connect the fixing part and the stirring part;

The stirring part is used to stir the growth solution driven by the graphite boat.

Optionally, a threaded rod is provided at one end of the fixed part, and the threaded rod is connected to the fixed rod and connected to the connecting part through the fixed rod.

Optionally, the length of the fixing rod is 10-15 mm.

Optionally, the fixing portion is screwed to a fixing hole on the outer side wall of the outer boat.

Optionally, the length of the connecting part is set according to the distance between the fixing hole on the outer boat and the growth tank, and the stirring part can pass through the connecting part to make the stirring part outside the growth tank The growth solution was stirred.

Optionally, the connecting portion is flat or fan-shaped.

Optionally, the stirring part is oval or fan-shaped.

Optionally, there are four swing arms, which are respectively symmetrically arranged on the four outer walls of the outer boat.

The beneficial effects of the present invention are as follows:

In the present invention, a plurality of swing arms are arranged on the outside of the graphite boat, specifically, a plurality of swing arms are arranged on the outside of the outer boat, and the movement of the swing arms is driven by the movement of the graphite boat, thereby realizing sufficient stirring of the growth solution, so that the growth solution The uniformity of the composition of the graphite boat is improved, and finally an epitaxial film with a uniform composition is obtained, which effectively solves the problem that the existing epitaxial film cannot be repeatedly obtained by graphite boats.

The above description is only an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the contents of the description, and in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable , the specific embodiments of the present invention are enumerated below.

Description of drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiment. The drawings are only for the purpose of illustrating a preferred embodiment and are not to be considered as limiting the invention. Also throughout the drawings, the same reference numerals are used to designate the same components. In the attached picture:

Fig. 1 is the structural representation of a kind of graphite boat that the embodiment of the present invention provides;

Fig. 2 is a schematic structural diagram of a swing arm provided by an embodiment of the present invention.

Detailed ways

The embodiment of the present invention aims at the problem that the existing epitaxial film with good effect cannot be repeatedly obtained through the graphite boat, by setting a plurality of swing arms on the outside of the graphite boat, and driving the movement of the swing arm through the movement of the graphite boat, so as to realize the The sufficient stirring of the growth solution improves the composition uniformity of the growth solution, and finally obtains an epitaxial film with uniform composition. The present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

The embodiment of the present invention provides a kind of graphite boat, referring to Fig. 1, this graphite boat comprises inner boat, outer boat and a plurality of swing arms that are arranged on the outer boat; The growth groove is above the square cavity on the lower side of the graphite boat), and a plurality of the swing arms are evenly distributed on the periphery of the outer boat, and the swing arms are used to stir the growth solution driven by the graphite boat , to increase the stirring effect on the growth solution, so that the composition uniformity of the growth solution is improved, and finally an epitaxial film with uniform composition is obtained.

In the embodiment of the present invention, the growth solution is stirred by the graphite boat and the swing arm arranged on the outer boat, so that the composition uniformity of the growth solution is improved, and finally an epitaxial film with uniform composition is obtained.

Referring to Fig. 2, in the embodiment of the present invention, the swing arm is Z-shaped, and the swing arm includes a fixing part, a connecting part and a stirring part, wherein the fixing part is used to fix the swing arm on the On the outer wall of the graphite boat; the connecting part is used to connect the fixing part and the stirring part; the stirring part is used to stir the growth solution driven by the graphite boat.

Specifically, in the embodiment of the present invention, one end of the fixing part is provided with a threaded rod, and the threaded rod is connected to the fixing rod and connected to the connecting part through the fixing rod.

That is to say, in the embodiment of the present invention, the fixing part is a long rod shape, and one end of the long rod is provided with a screw thread, which is connected with the fixing hole (that is, the circular cavity on the upper side of the graphite boat) on the outer boat through the screw thread, The other end of the long rod is connected with the connecting part. After the embodiment of the present invention calculates and sets the long rod to be tightened, the distance between the connecting part and the side wall of the outer boat is 10-15 millimeters. Experiments have proved that within this distance range A better stirring effect can be obtained.

Of course, in actual implementation, those skilled in the art can also set the distance between the connecting portion and the side wall of the outer boat according to the specific shapes of the connecting portion and the stirring portion and the growth solution to be stirred, which is not specifically limited in the present invention.

In addition, the length of the connection part in the embodiment of the present invention is set according to the distance between the fixing hole on the outer boat and the growth tank, and is set so that the stirring part can be connected outside the growth tank through the connection part. The growth solution is stirred.

That is to say, the length of the connecting portion can be set arbitrarily according to actual needs, and finally the stirring portion needs to be able to stir the growth solution around the growth tank.

During specific implementation, in order to improve the stirring effect, the connecting part can be in various shapes such as flat plate and fan, and the stirring part can also be in the shape of ellipse or fan. and various shapes can be set according to actual needs, which is not specifically limited in the present invention.

The graphite boat described in the embodiment of the present invention will be explained and illustrated in detail below through a specific example:

The content of solute Cd in the vertical liquid phase epitaxy growth solution in the mercury-rich state is very low, and Cd has a great influence on the material composition, wavelength, and surface morphology in HgCdTe materials. When the Cd content is very low, the growth window in the phase diagram of vertical liquid phase epitaxy is narrow, that is, if Cd is unevenly distributed in the growth solution, the growth thickness and composition gradient of the material will vary greatly, which makes the growth process difficult on the one hand. Large, on the other hand makes the quality of the material uncontrollable. During the growth process of vertical liquid phase epitaxy, the growth solution is always in a high temperature state, and it changes continuously with the growth process of cooling down. The single crystal thin film with stable growth quality and good batch consistency requires a growth solution with good composition uniformity. accomplish.

In view of the above problems, the present invention is mainly used to solve the problem of improving the uniformity of the growth solution in the vertical liquid phase epitaxy process, and to form a standard process for a type of thin film material (thickness, composition, surface morphology, etc.) to improve the consistency of the epitaxy process .

The scheme that the present invention solves its technical problem adopts is:

In the actual growth process, the growth solution is one of the key factors affecting the quality of the film. To improve the uniformity of the growth solution, the growth solution can be calcined at high temperature, and the oscillating rotation is performed during the calcination process. In the existing vertical liquid phase epitaxy process, the uniformity of the growth solution is improved by the swing of the graphite boat in the growth solution, but the small volume of the graphite boat is not enough to agitate the growth solution. If the volume of the graphite boat is simply increased to increase Large agitation of the growth solution requires re-adjustment of process parameters to achieve epitaxial film preparation, resulting in increased process adjustment costs and graphite boat processing costs.

By increasing the disturbance of the growth solution during the growth of the HgCdTe film, the composition uniformity of the HgCdTe material is improved. The specific solution is to add a swing arm outside the graphite boat to increase the contact area between the graphite boat and the growth solution. , enhance the agitation effect of the graphite boat on the growth solution, and improve the component uniformity of the mercury cadmium telluride material.

The scheme adopted in the embodiment of the present invention includes two parts: the swing arm and the outer boat, and the contact area with the growth solution is increased by adding the swing arm to the outer boat. In this way, since the main structure of the graphite boat does not change, the purpose of improving the uniformity of the growth solution can be achieved without changing the process parameters and the like, ensuring the quality consistency of multiple batches of thin film materials.

The embodiment of the present invention does not need to reprocess the graphite boat, which can effectively save the cost of graphite boat processing and the time for adjusting process parameters when the process is changed, thereby ensuring the consistency of the liquid phase epitaxy process and the quality stability of multiple batches of thin film materials.

The quality of multiple batches of film materials epitaxy out through the graphite boat structure is consistent. Compared with the conventional graphite boat structure, the epitaxial thin film material under the same process parameters can improve the quality of the thin film material and improve the consistency and repeatability of the vertical liquid phase epitaxy process.

That is to say, in the embodiment of the present invention, in the vertical liquid phase epitaxy process, the outer boat with swing arms is used to increase the contact area between the graphite boat and the growth solution during the process, so that the graphite boat can be more fully covered during the swing process. By perturbing the growth solution, this design further enhances the compositional uniformity of the raw HgCdTe material. Through the above beneficial effects, the quality of a single film material, the process repeatability and the quality consistency of multiple batches of film materials can be effectively improved.

Adopting the graphite boat described in the embodiments of the present invention comprises the following steps:

1. Make threaded holes (fixed holes) at the outer part of the graphite boat;

2. Screw the suitable graphite swing arm onto the graphite boat;

3. Place the graphite boat with the swing arm in the vertical liquid phase epitaxy equipment to start the epitaxy process;

4. When the epitaxial process is over, take the swing arm from the graphite outer boat and take out the graphite outer boat;

To sum up, the preparation of the graphite boat with swing arms according to the present invention can effectively improve the disturbance to the growth solution, thereby improving the component uniformity of the HgCdTe material and the process repeatability and consistency of the liquid phase epitaxy process. The experimental results show that the standard deviation of the components of the thin film materials prepared by using graphite boats with swing arms is reduced from 0.0015 to 0.001 compared with those prepared by graphite boats without swing arms, and the composition uniformity is greatly improved. The performance is good, and the beneficial effects of the present invention are effectively realized.

Although preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, and therefore, the scope of the present invention should not be limited to the above-described embodiments.

Claims (10)

1. A graphite boat, comprising: the device comprises an inner boat, an outer boat and a plurality of swing arms arranged on the outer boat;

the swing arm sets up the growth groove top of outer boat, and a plurality of the swing arm equipartition is in the periphery of outer boat, the swing arm is used for stirring growth solution under the drive of graphite boat to increase right growth solution's stirring effect for growth solution's component homogeneity obtains promoting, finally obtains the epitaxial film that the composition is even.

2. The graphite boat of claim 1,

the swing arm is fixed on the side wall of the outer boat through insertion.

3. The graphite boat of claim 1,

the swing arm is Z-shaped and comprises a fixing part, a connecting part and a stirring part;

the fixing part is used for fixing the swing arm on the outer side wall of the outer boat;

the connecting part is used for connecting the fixing part and the stirring part;

and the stirring part is used for stirring the growth solution under the driving of the graphite boat.

4. The graphite boat of claim 3,

and one end of the fixing part is provided with a screw rod, and the screw rod is connected with a fixing rod and is connected with the connecting part through the fixing rod.

5. The graphite boat according to claim 4,

the length of the fixed rod is 10-15 mm.

6. The graphite boat according to claim 3,

the fixing part is screwed to a fixing hole on the outer side wall of the outer boat.

7. The graphite boat of claim 6,

the length of the connecting part is set according to the distance between a fixing hole on the outer boat and the growth tank, and the stirring part can stir the growth solution outside the growth tank through the connecting part.

8. The graphite boat of claim 3,

the connecting part is in a flat plate shape or a fan shape.

9. The graphite boat according to claim 3,

the stirring part is in an oval shape or a fan shape.

10. The graphite boat according to any one of claims 1 to 9,

the number of the swing arms is four, and the four swing arms are respectively and symmetrically arranged on the outer walls of the four sides of the outer boat.

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