A kind of method for synthesizing gallium phosphide polycrystalTechnical field
The present invention relates to a kind of heating synthesis technique, specifically, relate to a kind of method for synthesizing gallium phosphide polycrystal.
Background technology
The drawing of monocrystal of gallium phosphide derives from the synthetic gallium phosphide polycrystal.And the synthetic of gallium phosphide polycrystal is in the crystal reaction tube of sealing, to carry out.In the process of synthetic gallium phosphide polycrystal, crystal reaction tube is because the gasification of phosphorus can produce than normal atmosphere, and general way is to make the crystal reaction tube inner and outer air pressure reach balance through the outer air pressure of control crystal reaction tube at present, thereby is unlikely to bombing.Yet; In the process of the synthetic gallium phosphide polycrystal of tradition, adopt the ultra-high frequency type of heating at present usually; This type of heating has adopted the HF oscillation pipe, and the output oscillating voltage of this HF oscillation pipe has arrived 7000~8000V, and output frequency has reached 200~300kHz; Can produce stronger electromagnetic radiation thereupon, HUMAN HEALTH is worked the mischief.And; Can find out that from practice this traditional ultra-high frequency adds thermal synthesis gallium phosphide polycrystal method and occurs the bombing situation easily, synthetic gallium phosphide polycrystal transparency is lower; And the situation that electrode is struck sparks appears under hot and humid environment easily, the HF oscillation pipe also damages easily.
Summary of the invention
The object of the present invention is to provide a kind of method for synthesizing gallium phosphide polycrystal, this method can reduce the bombing number of times in the gallium phosphide polycrystal building-up process, and can not produce the electrode spark phenomenon, can not work the mischief to HUMAN HEALTH.
In order to achieve the above object, the present invention has adopted following technical scheme:
A kind of method for synthesizing gallium phosphide polycrystal is characterized in that: this method adopts the synthetic gallium phosphide of medium-high frequency type of heating, comprises step:
Step 1: cling to post-heating at the indoor nitrogen 5~10 that charges into of synthetic furnace, and the indoor nitrogen gas pressure of synthetic furnace is maintained in the scope of 20~30 crust;
Step 2: the phosphorus stove is warming up in 480~520 ℃ the scope; The back stove is warming up in 700~800 ℃ the scope; The electric current that feeds in the ruhmkorff coil is risen in the scope of 40~150A; The output voltage of ruhmkorff coil is controlled in the scope of 5~15V and frequency modulation to 10~20KHz, so that induction region heats up;
Step 3: the temperature of confirming phosphorus stove, back stove is raised in the design temperature scope also stable; And the output voltage of the electric current in the ruhmkorff coil, ruhmkorff coil and frequency reaches in the setting range and after stable; In ruhmkorff coil, move crystal reaction tube with 6.5 centimetres/hour speed; The phosphorus stove is heated up simultaneously, to implement the building-up process of gallium phosphide with 10~35 ℃/hour temperature rise rate;
Step 4: after 4 hours gallium phosphide building-up process, slowly the ruhmkorff coil frequency is reduced to zero from mxm., will synthesizes the furnace chamber release.
Said method for synthesizing gallium phosphide polycrystal also comprises: after confirming synthetic furnace chamber release, open bell, take out crystal reaction tube; Crystal reaction tube is put into water to be broken; Take out carbon tube, and cut carbon tube, with synthetic gallium phosphide polycrystal ingot surface polishing light in the carbon tube.
It is 50~60 minutes that electric current in the said ruhmkorff coil is risen to the used time of 40~150A.
It is less than 1 hour that said ruhmkorff coil frequency is reduced to the zero used time from mxm..
The present invention has following characteristics:
1, because method for synthesizing gallium phosphide polycrystal of the present invention adopts the synthetic gallium phosphide of medium-high frequency type of heating; The ruhmkorff coil output voltage has only 5~15 volts, and frequency has only 10~20KHz, therefore; The present invention has greatly reduced the bombing number of times in the gallium phosphide polycrystal building-up process; Improved the rate of coming out of the stove and the quality of gallium phosphide polycrystal, compared with conventional phosphatizing gallium polycrystalline compound method, the qualification rate of the gallium phosphide polycrystal of every stove output has improved 5%.
2, because method for synthesizing gallium phosphide polycrystal of the present invention adopts the synthetic gallium phosphide of medium-high frequency type of heating, and the ruhmkorff coil output voltage has only 5~15 volts, therefore, under hot and humid environment, the phenomenon of electrode sparking is not prone to yet.
3, because the frequency of using in the method for synthesizing gallium phosphide polycrystal of the present invention has only 10~20KHz, therefore, can not produce strong electromagnetic radiation, HUMAN HEALTH can not endangered.
Method for synthesizing gallium phosphide polycrystal of the present invention adopts the synthetic gallium phosphide of medium-high frequency type of heating; Greatly reduced the bombing number of times in the gallium phosphide polycrystal building-up process; The rate of coming out of the stove and the quality of gallium phosphide polycrystal have been improved; Be difficult for producing the electrode spark phenomenon, also can not produce strong electromagnetic radiation, can not influence HUMAN HEALTH.
Description of drawings
Fig. 1 is the realization flow figure of method for synthesizing gallium phosphide polycrystal of the present invention.
Embodiment
Below in conjunction with accompanying drawing the present invention is further described.
As shown in Figure 1, method for synthesizing gallium phosphide polycrystal of the present invention comprises step:
Step 1: cling to (bar) post-heating at the indoor nitrogen 5~10 that charges into of synthetic furnace, and the indoor nitrogen gas pressure of synthetic furnace is maintained in the scope of 20~30 crust.
Step 2: the phosphorus stove is warming up in 480~520 ℃ the scope; The back stove is warming up in 700~800 ℃ the scope; The electric current that feeds in the ruhmkorff coil is risen in the scope of 40~150A and in the scope of frequency modulation to 10~20KHz, so that the induction region in the ruhmkorff coil heats up.Generally, the electric current in the ruhmkorff coil being risen to the time used in 40~150A scope is 50~60 minutes.
Step 3: the temperature of confirming phosphorus stove, back stove is raised in the design temperature scope also stable; And the electric current in the ruhmkorff coil and frequency thereof reach in the setting range and after stable; Move crystal reaction tube with 6.5 centimetres/hour speed (in ruhmkorff coil hollow space) in ruhmkorff coil; The phosphorus stove is heated up simultaneously, to implement the building-up process of gallium phosphide with 10~35 ℃/hour temperature rise rate.
Step 4: after 4 hours gallium phosphide building-up process, slowly the ruhmkorff coil frequency is reduced to zero from mxm., will synthesizes the furnace chamber release.Generally, the ruhmkorff coil frequency being reduced to for zero used time from mxm. is less than 1 hour.
In reality is implemented, after confirming synthetic furnace chamber release, should open bell, take out crystal reaction tube, crystal reaction tube is put into water break, take out carbon tube, and cut carbon tube, with synthetic gallium phosphide polycrystal ingot surface polishing light in the carbon tube.
What at present traditional synthetic gallium phosphide polycrystal method adopted is the ultra-high frequency type of heating; Be the polycrystalline synthetic furnace (for example; Britain Camb PGR1400 type polycrystalline synthetic furnace) heating circuit in is the ultra-high frequency heating circuit; The output oscillating voltage of this type of heating has reached 7000~8000V, and frequency has reached 200~300KHz.This type of heating brought bombing often, final product quality is poor, radiation is strong, be prone to shortcomings such as sparking.Yet, in the invention described above method for synthesizing gallium phosphide polycrystal, employing be the medium-high frequency type of heating; Just make the frequency of ruhmkorff coil remain in the scope of medium-high frequency, and in the present invention, the output voltage of ruhmkorff coil is controlled at 5~15V; Magnitude of voltage is very low, and the electric current in the ruhmkorff coil can reach in the scope of 40~150A, in the process of synthetic gallium phosphide polycrystal; The power of ruhmkorff coil consumption is merely 10~15kw, is the half the of traditional ultra-high frequency heating circuit power consumption.
When reality is implemented,, the ultra-high frequency heating circuit in the polycrystalline synthetic furnace of tradition use gets final product embodiment of the present invention as long as being replaced by the medium-high frequency heating circuit.And realize that specifically the medium-high frequency heating circuit belongs to the known technology that the electricity field technician knows, so here repeat no more.
The present invention has following characteristics:
1, because method for synthesizing gallium phosphide polycrystal of the present invention adopts the synthetic gallium phosphide of medium-high frequency type of heating; The ruhmkorff coil output voltage has only 5~15 volts, and frequency has only 10~20KHz, therefore; The present invention has greatly reduced the bombing number of times in the gallium phosphide polycrystal building-up process; Improved the rate of coming out of the stove and the quality of gallium phosphide polycrystal, compared with conventional phosphatizing gallium polycrystalline compound method, the qualification rate of the gallium phosphide polycrystal of every stove output has improved 5%.
2, because method for synthesizing gallium phosphide polycrystal of the present invention adopts the synthetic gallium phosphide of medium-high frequency type of heating, and the ruhmkorff coil output voltage has only 5~15 volts, therefore, under hot and humid environment, the phenomenon of electrode sparking is not prone to yet.
3, because the frequency of using in the method for synthesizing gallium phosphide polycrystal of the present invention has only 10~20KHz, therefore, can not produce strong electromagnetic radiation, HUMAN HEALTH can not endangered.
Method for synthesizing gallium phosphide polycrystal of the present invention adopts the synthetic gallium phosphide of medium-high frequency type of heating; Greatly reduced the bombing number of times in the gallium phosphide polycrystal building-up process; The rate of coming out of the stove and the quality of gallium phosphide polycrystal have been improved; Be difficult for producing the electrode spark phenomenon, also can not produce strong electromagnetic radiation, can not influence HUMAN HEALTH.
The above is preferred embodiment of the present invention and the know-why used thereof; For a person skilled in the art; Under the situation that does not deviate from the spirit and scope of the present invention; Any based on conspicuous changes such as the equivalent transformation on the technical scheme of the present invention basis, simple replacements, all belong within the protection domain of the present invention.