CN104213195B

CN104213195B - A kind of low temperature PVT controls the method for crystal growth wrappage defect

Info

Publication number: CN104213195B
Application number: CN201410492711.5A
Authority: CN
Inventors: 程红娟; 司华青; 李璐杰; 徐永宽; 练小正; 张志鹏
Original assignee: CETC 46 Research Institute
Current assignee: CETC 46 Research Institute
Priority date: 2014-09-24
Filing date: 2014-09-24
Publication date: 2016-08-24
Anticipated expiration: 2034-09-24
Also published as: CN104213195A

Abstract

nullThe present invention relates to a kind of method controlling low temperature PVT bulk growth wrappage defect,Step is as follows: use PVT single crystal growing furnace,At cavity internal gas pressure 800 ~ 1000mbar that the employings in 2 ~ 6 hours at crystal growth initial stage are of a relatively high，And keep thermograde 15 ~ 30 DEG C bigger at seed crystal，So that the growth rate of monocrystalline was controlled within 0.05 ~ 0.15mm/ hour，After early growth period terminates for 2 ~ 6 hours，It is gradually lowered air pressure 100 ~ 400mbar，And reduce the thermograde 2 ~ 10 DEG C of monocrystalline at seed crystal，To increase the growth rate of high quality crystal to 0.2 ~ 0.5mm/ hour，Grow the pressure 900 ~ 1100mbar that increases sharply after terminating，Reduce thermograde 0 ~ 2 DEG C at seed crystal further，Have the technical effect that wrappage powder injection molding in less scope，Improve crystal volume available and crystal mass.

Description

A kind of low temperature PVT controls the method for crystal growth wrappage defect

Technical field

The present invention relates to a kind of low temperature PVT and control method for monocrystal growth, control low temperature PVT body monocrystalline particularly to one raw The method of long wrappage defect.

Background technology

II-VI group compound semiconductor has direct transition band structure, and with its distinctive light transfer characteristic, solid The aspects such as body luminescence, laser, infrared, piezoelectric effect and light-sensitive device are widely used.But owing to II-VI group compound is universal Having fusing point height, growth air pressure high, liquid phase method growth is higher to equipment requirements.Sublimed method (PVT) is used the most only to need Wanting relatively low temperature (less than 1100 DEG C), therefore, PVT method becomes the important method of preparation II-VI group compound.But at body monocrystalline In material PVT method growth course, often producing the defect of some macroscopic views, such as wrappage etc., its diameter is in micron dimension, long The defects such as degree is even up to millimeter magnitude, the quality of crystal particularly wrappage will have a strong impact on used volume and the device of crystal The performance of part and stability, therefore in high quality bulk single crystal preparation process, generally require by certain technological means lacking It is trapped into row suppression, at utmost reduces the impact of defect.

Summary of the invention

The II-VI group compound monocrystal preparation research carried out both at home and abroad at present is considerably less, the pattern to its wrappage defect Feature, mechanism of production and control device research are less, and the present invention is by growth temperature during bulk growth and pressure Adjustment, control the generation of wrappage defect and distribution, improve crystal mass, concrete technical scheme is, a kind of low temperature PVT controls the method for crystal growth wrappage defect, and step is as follows: 1), uses PVT single crystal growing furnace, raw material, seed crystal, substrate is put Entering and specify position, depending on raw material and seed crystal are by II-VI group monocrystalline to be grown, substrate uses sapphire or quartz polished silicon wafer；2), At 2 ~ 6 hours of the crystal growth initial stage, wrappage defect gap between seed crystal and substrate was assembled, and now uses relative chamber Internal air pressure 800 ~ 1000mbar, and to keep thermograde at seed crystal be 15 ~ 30 DEG C, the growth rate of monocrystalline to be controlled Within 0.05 ~ 0.15mm/ hour, and increase wrappage defect and produce and the speed of movement, promote wrappage defect to remove crystal； 3), when after end in 2 ~ 6 hours of early growth period, it is gradually lowered air pressure to 100 ~ 400mbar, and reduces the temperature of monocrystalline at seed crystal Gradient is 2 ~ 10 DEG C, to increase the growth rate of crystal to 0.2 ~ 0.5mm/ hour, and the movement of suppression wrappage defect so that it is stagnant Stay near seed crystal；4), growth terminate after the pressure that increases sharply to 900 ~ 1100mbar, reduce thermograde at seed crystal further It it is 0 ~ 2 DEG C, by wrappage powder injection molding in less scope；5), program end of run, take out growth tube and supporting construction, I.e. can get the II-VI group monocrystalline that wrappage defect distribution is concentrated.

The technological merit of the present invention is the adjustment by growth technique, and in making monocrystal, inclusion enclave defect is trapped in distance seed In brilliant nearer layer-shaped area, the large area diffusion of suppression defect, improve crystal volume available and crystal mass.

Accompanying drawing explanation

Fig. 1 is the mobile schematic diagram of crystal growth defect of the present invention suppression.

Fig. 2 is that the present invention has seed body monocrystalline PVT to grow schematic diagram.

Specific embodiments

As a example by PVT method prepares the method for CdS monocrystalline, as shown in Figure 1, 2, CdS crystal growth uses five warm area PVT crystal raw Long stove, the warm area from feed end to substrate terminal is respectively one to five warm areas, with sapphire polished silicon wafer as substrate.

1), raw material 1, seed crystal 2, substrate 3 being put into appointment position, raw material 1 uses CdS powder, seed crystal 2 to use Ф 30mm CdS monocrystalline, substrate 3 uses quartz polished silicon wafer；

2), the crystal growth initial stage be called for short the stage I, the warm area in crystal growth be set to 1055 DEG C, 1030 DEG C of raw material 1 district, 990 DEG C, 985 DEG C of seed crystal district, 970 DEG C, pressure set is 600mbar, and first growth cycle is set as 3 hours；

3) trophophase, after the crystal growth initial stage terminates is called for short the stage II, and warm area is adjusted to 1055 DEG C, places raw material 1 1030 DEG C of district, 990 DEG C, 985 DEG C of seed crystal district, 985 DEG C, pressure set is 200mbar, constant temperature 20 ~ 200h, keep crystal growth；

4), it is called for short the stage III after the crystal growth phase terminates, runs cooling process and ensure that at seed crystal, warm area temperature is identical, Pressure set is 1000mbar, is reduced to room temperature；

5), treat program end of run, take out growth tube 4, i.e. can get the high-quality CdS monocrystalline 6 that defect distribution is concentrated.

Claims

1. the method that low temperature PVT controls crystal growth wrappage defect, step is as follows:

1), use PVT single crystal growing furnace, raw material (1), seed crystal (2), substrate (3) are put into appointment position, raw material (1) and seed crystal (2) by Depending on II-VI group monocrystalline to be grown, substrate (3) uses sapphire or quartz polished silicon wafer；

2), monocrystalline (6) early growth period 2 ~ 6 hours, the wrappage defect (7) gap between seed crystal (2) and substrate (3) is gathered Collection, now uses cavity internal gas pressure 800 ~ 1000mbar, and to keep seed crystal (2) place thermograde is 15 ~ 30 DEG C, with by monocrystalline (6) growth rate controlled within 0.05 ~ 0.15mm/ hour, and increased the speed that wrappage defect (7) produces and moves, Wrappage defect (7) is promoted to remove crystal；

3) trophophase, after early growth period 2 ~ 6 hours terminates, is gradually lowered air pressure to 100 ~ 400mbar, and reduces seed crystal (2) thermograde of place's monocrystalline (6) is 2 ~ 10 DEG C, to increase the growth rate of crystal to 0.2 ~ 0.5mm/ hour, and suppression parcel The movement of thing defect (7) so that it is be trapped near seed crystal (2)；

4), the trophophase pressure that increases sharply after terminating to 900 ~ 1100mbar, reduce further seed crystal (2) place thermograde be 0 ~ 2 DEG C, wrappage defect (7) is controlled in less scope；

5), program end of run, take out growth tube (4) and supporting construction (5), i.e. can get wrappage defect (7) distribution and concentrate II-VI group monocrystalline (6).