阅读说明：本技术 一种单晶制绒的提拉方法及装置 (Pulling method and device for single crystal texturing ) 是由 贾永前 樊欢欢 董慧 于 2019-11-19 设计创作，主要内容包括：本发明提供一种单晶制绒的提拉方法及装置,其中,单晶制绒的慢提拉方法,用于硅片的预脱水中,所述硅片装在花篮的插槽中,包括：在所述硅片离开水的表面之前,将盛装所述硅片的花篮倾斜第一角度；在所述硅片离开水的表面之后,将盛装所述硅片的花篮倾斜第二角度,以所述硅片向所述插槽的侧壁倾斜的角度,所述第一角度小于第二角度。根据本发明实施例的光单晶制绒的提拉方法,能够在单晶制绒清洗硅片过程中,提高硅片脱水效果,减少硅片边缘制绒发白的问题,提高硅片良品率。(The invention provides a pulling method and a device for single crystal texturing, wherein the slow pulling method for single crystal texturing is used for pre-dewatering of silicon wafers, the silicon wafers are arranged in slots of a basket, and the pulling method comprises the following steps: before the silicon wafer leaves the surface of the water, inclining a flower basket containing the silicon wafer by a first angle; after the silicon wafer leaves the surface of the water, the flower basket containing the silicon wafer is inclined at a second angle, and the first angle is smaller than the second angle according to the angle of the silicon wafer inclined to the side wall of the slot. According to the pulling method for the optical single crystal texturing, provided by the embodiment of the invention, the dehydration effect of the silicon wafer can be improved, the problem of whitening of the texturing edge of the silicon wafer can be reduced, and the yield of the silicon wafer can be improved in the process of cleaning the silicon wafer by the optical single crystal texturing.)

1. A slow pulling method for texturing a single crystal, which is used for pre-dewatering silicon wafers, wherein the silicon wafers are arranged in slots of a flower basket, and the slow pulling method is characterized by comprising the following steps:

before the silicon wafer leaves the surface of the water, inclining a flower basket containing the silicon wafer by a first angle;

after the silicon wafer leaves the surface of the water, the flower basket containing the silicon wafer is inclined at a second angle, and the first angle is smaller than the second angle.

2. The method of claim 1, wherein the first angle ranges between 0 ° and 10 °.

3. The method as claimed in claim 2, wherein the second angle is 20-40 ° when the thickness of the silicon wafer is 165-180 μm.

4. The method of claim 1, further comprising:

and controlling the first angle and the second angle of the inclination of the flower basket through a control program.

5. The method of claim 1, wherein the time for pulling the wafer in water before the wafer leaves the surface of the water is 10 to 60s, and the time for pulling the wafer after the wafer leaves the surface of the water is 10 to 60 s.

6. A slow pulling device for single crystal texturing is characterized by comprising:

a lifting frame;

the flower basket is fixed on the lifting frame, and a plurality of slots for containing silicon wafers are formed in the flower basket;

the driving device is connected with the lifting frame and used for driving the lifting frame to turn over so as to adjust the inclination angle of the flower basket;

the driving device drives the flower basket containing the silicon wafers to incline by a first angle before the silicon wafers leave the surface of the water, so that the silicon wafers incline towards the side walls of the slots, and drives the flower basket containing the silicon wafers to incline by a second angle after the silicon wafers leave the surface of the water, so that the inclination angle of the silicon wafers towards the side walls of the slots is increased, and the first angle is smaller than the second angle.

7. The apparatus of claim 6, further comprising:

the controller is connected with the driving device and controls the driving device to drive the flower basket containing the silicon wafers to incline at a first angle before the silicon wafers leave the surface of water, and to drive the flower basket containing the silicon wafers to incline at a second angle after the silicon wafers leave the surface of water.

8. The apparatus of claim 6, wherein the first angle ranges between 0 ° and 10 °.

9. The device as claimed in claim 6, wherein the second angle is 20-40 ° when the thickness of the silicon wafer is 165-180 μm.

10. The apparatus of claim 7, further comprising:

and the liquid level sensor is connected with the controller and is used for monitoring whether the silicon wafer leaves the surface of water or not.

Technical Field

The invention relates to a pulling method and a pulling device for single crystal texturing.

Background

In the process of processing a monocrystalline silicon wafer, a diamond wire cutting technology is increasingly adopted, the diamond wire cutting belongs to fixed abrasive cutting and contrast sand wire cutting, and the diamond wire cutting is characterized in that the surface is compact and smooth, in the subsequent monocrystalline silicon wafer texturing process, the reaction speed of alkali liquor and the surface of the diamond wire cut silicon wafer is relatively slow, the masking capability of the texturing process on dirt is weakened, the problems of texturing, white spots, white edges and the like can be caused, the existing monocrystalline cleaning process only pays attention to the medicament proportion and the additive amount of the silicon wafer, and fine adjustment of the medicament tank cleaning time and the cleaning temperature, but the improvement on the monocrystalline texturing dirt is not ideal.

Disclosure of Invention

Accordingly, the present invention provides a method and an apparatus for pulling a single crystal texture etching material to improve the uniformity of dehydration and cleanliness of a silicon wafer after texture etching.

In order to solve the technical problems, the invention adopts the following technical scheme:

the slow pulling method for single crystal texturing according to the embodiment of the first aspect of the invention is used for pre-dewatering silicon wafers, wherein the silicon wafers are arranged in slots of a flower basket, and the slow pulling method comprises the following steps:

before the silicon wafer leaves the surface of the water, inclining a flower basket containing the silicon wafer by a first angle;

after the silicon wafer leaves the surface of the water, the flower basket containing the silicon wafer is inclined by a second angle so as to enable the silicon wafer to be inclined towards the side wall of the slot, and the first angle is smaller than the second angle.

The first angle and the second angle are angles of the bottom plane of the flower basket relative to the surface of water.

Preferably, the first angle range is between 0 ° and 10 °.

Preferably, when the thickness of the silicon wafer is 165-180 μm, the second angle is 20-40, preferably 21 °.

Preferably, the first angle and the second angle at which the flower basket is inclined are controlled by a control program.

Preferably, the time for pulling the wafer in water before the wafer leaves the surface of the water is 10 to 60s, preferably 30s, and the time for pulling the wafer after the wafer leaves the surface of the water is 10 to 60s, preferably 30 s.

According to the second aspect of the invention, the slow pulling device for single crystal texturing comprises:

a lifting frame;

the flower basket is fixed on the lifting frame, and a plurality of slots for containing silicon wafers are formed in the flower basket;

the driving device is connected with the lifting frame and used for driving the lifting frame to turn over so as to adjust the inclination angle of the flower basket;

the driving device drives the flower basket containing the silicon wafers to incline by a first angle before the silicon wafers leave the surface of the water, so that the silicon wafers incline towards the side walls of the slots, and drives the flower basket containing the silicon wafers to incline by a second angle after the silicon wafers leave the surface of the water, so that the inclination angle of the silicon wafers towards the side walls of the slots is increased, and the first angle is smaller than the second angle.

Preferably, the slow pulling device for single crystal texturing further comprises:

the controller is connected with the driving device and controls the driving device to drive the flower basket containing the silicon wafers to incline at a first angle before the silicon wafers leave the surface of water, and to drive the flower basket containing the silicon wafers to incline at a second angle after the silicon wafers leave the surface of water.

Preferably, the first angle ranges between 0 ° and 10 °.

Preferably, when the thickness of the silicon wafer is 165-180 μm, the second angle is 20-40 °, preferably 21 °.

Preferably, the slow pulling device for single crystal texturing further comprises:

and the liquid level sensor is connected with the controller and is used for monitoring whether the silicon wafer leaves the surface of water or not.

The technical scheme of the invention at least has one of the following beneficial effects:

according to the pulling method and the pulling device for the single crystal texturing, the uniformity of silicon wafer dehydration can be improved, the phenomena of white spots and white edges of the silicon wafer texturing can be improved, the later processing cost can be saved, and the yield of the silicon wafer can be ensured in the dehydration process of the single crystal texturing.

Drawings

FIG. 1 is a flow chart of a pulling method for single crystal texturing according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a pulling apparatus for single crystal texturing according to an embodiment of the present invention;

FIG. 3 is a diagram illustrating a state where the pulling apparatus for single crystal texturing adjusts the inclination angle of the pulling frame to 0 ° according to the embodiment of the present invention;

FIG. 4 is a diagram illustrating a state where the pulling apparatus for single crystal texturing adjusts the tilt angle of the pull-up basket to 10 degrees according to the embodiment of the present invention;

FIG. 5 is a diagram showing a state where the pulling apparatus for single crystal texturing adjusts the inclination angle of the pulling frame to 21 degrees according to the embodiment of the present invention; .

FIG. 6 is a diagram illustrating a state where a basket of a single crystal texturing pulling apparatus according to an embodiment of the present invention is tilted at an angle of 21 °.

Reference numerals:

a flower basket 10;

a lifting frame 20;

a drive means 30.

Detailed Description

First, a method for pulling a single crystal texture etching according to an embodiment of the first aspect of the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, the pulling method for single crystal texturing according to the embodiment of the invention is used for pre-dewatering of a silicon wafer, and comprises the following steps:

in step S10, the basket holding the silicon wafer is tilted a first angle before the silicon wafer leaves the surface of the water. Wherein, be equipped with a plurality of slots that are used for the splendid attire silicon chip in the basket of flowers, when the first angle of basket of flowers slope, will influence the inclination of silicon chip in the slot, and then influence the effect of dehydration.

Step S20, after the silicon wafer leaves the surface of the water, tilting the basket holding the silicon wafer by a second angle, the first angle being smaller than the second angle, at which the silicon wafer is tilted toward the sidewall of the slot.

It can be understood that the inclination angle of the flower basket can change the inclination angle of the silicon wafer in the flower basket, that is, the contact position and the contact area of the side wall of the slot and the silicon wafer can be influenced, and in the process of silicon wafer dehydration, the smaller the contact area of the side wall of the flower basket and the silicon wafer is, the better the silicon wafer dehydration effect is.

Further, the silicon chip also can influence the inclination of silicon chip in aquatic and the different external force that receive on water, and then influence the position and the area of contact of the contact between silicon chip and the slot lateral wall, this application is through making the basket of flowers slope first angle in aquatic, leave the basket of flowers second angle of slope when the surface of boiled water, first angle is less than the second angle, with the dehydration effect that improves the silicon chip, it can be understood that, the silicon chip is even on the relative aquatic of the atress of aquatic, and when the silicon chip leaves the surface of boiled water, can receive the gravity of silicon chip self, and the tensile influence of remaining water between silicon chip and slot diapire or the lateral wall, make the silicon chip on water and underwater dehydration condition different. Consequently, this application sets up the second angle for being greater than first angle, can make the silicon chip on water and the dehydration that all can be fine under water, and then improves the dehydration effect of silicon chip, avoids the silicon chip because of the not good problem that leads to silicon chip texturing lace of dehydration effect.

Therefore, according to the slow pulling method for monocrystalline texturing provided by the embodiment of the invention, the contact position and the contact area of the silicon wafer and the flower basket in the water state and the water state are changed by changing the inclination angle of the flower basket in the water and on the water, so that the dehydration effect of the silicon wafer is improved as much as possible, the problems of white and white edges of the textured silicon wafer are avoided, and the quality of the silicon wafer is improved.

Specifically, according to one embodiment of the present invention, the first angle range is between 0 ° and 10 °. Preferably, the first angular range may be set to 0 °.

That is to say, the silicon chip and the bottom wall of the flower basket are vertical or nearly vertical, and meanwhile, the flower basket adopts a vertical slow-pulling mode, so that the phenomenon of water hanging on two sides can be effectively reduced when the silicon chip is pulled upwards, and the ratio of the water hanging pieces and the ratio of the white edge of the texture surface are obviously reduced. Preferably, when the first angle range is 0 degrees, the uniform dehydration of the silicon wafer is facilitated, and the problem of frizzy and whitish edges of the silicon wafer is reduced.

According to a preferred embodiment of the present invention, when the thickness of the silicon wafer is 165-180 μm, the second angle is 20-40 °, preferably 21 °, further, when the thickness of the silicon wafer is 170 μm, the second angle is 21 °, the water hanging ratio and the texturing white edge ratio are low, and the quality of the silicon wafer is improved.

In order to find the best inclination angle when the basket is slowly pulled by the monocrystal texturing pulling method, a first angle (the inclination angle of the basket before the silicon wafer leaves the surface of water) is set to be 0 degree and 10 degrees, and a second angle (the inclination angle of the basket after the silicon wafer leaves the surface of water) is set to be 0 degree, 10 degrees and 21 degrees respectively. And counting the number of the water hanging pieces and the number of the texturing white edges after the silicon wafer is dehydrated in the test, and calculating to obtain the ratio of the water hanging pieces and the ratio of the texturing white edges. A number of experiments were performed on 170 μm thick silicon wafers. The experimental results are shown in table 1 below.

TABLE 1

As can be seen from table 1, when the first angle is 0 ° or 10 ° and the second angle is 21 °, the water-hanging sheet ratio is 0.01 and 0.02, respectively, and the matte white edge ratio is 0.20% and 1.22%, respectively, that is, the second angle has a low water-hanging sheet ratio at 21 ° and has a low water-hanging sheet ratio and matte white edge ratio at 0 ° and 21 °.

According to another embodiment of the present application, the first and second angles at which the flower basket 10 is tilted are controlled by a control program. That is, the control program can flexibly set the first angle and the second angle at which the flower basket 10 is inclined. According to the difference of silicon chip thickness, can also set up the first angle and the second angle of different flower basket slopes, more intelligent, more be favorable to the silicon chip of thickness difference evenly to dewater, reduce the problem that the silicon chip edge becomes fine hair and turns white.

Preferably, the time for pulling the wafer in water before the wafer leaves the surface of the water is 30s, and the time for pulling the wafer after the wafer leaves the surface of the water is 30 s.

Specifically, the pulling time of the silicon wafer in water and the pulling time of the silicon wafer after leaving the surface of water can be controlled through a control program, and the pulling time of different silicon wafers in water and after leaving the surface of water can be set according to different thicknesses of the silicon wafers, so that the silicon wafers can be uniformly dehydrated, and the problem of wool making and whitening on the edges of the silicon wafers is solved.

As shown in fig. 2 to 6, the pulling apparatus for single crystal texturing according to the embodiment of the second aspect of the present invention includes a pulling frame 20, a flower basket 10 and a driving apparatus 30.

Specifically, the flower basket 10 is fixed on the lifting frame 20, a plurality of slots for containing silicon wafers are arranged inside the flower basket 10, and the driving device 30 is connected with the lifting frame 20 and used for driving the lifting frame 20 to overturn so as to adjust the inclination angle of the flower basket 10, that is, the inclination angle of the flower basket 10 is controlled by controlling the inclination of the lifting frame 20, and the inclination angle of the silicon wafers in the flower basket 10 is further controlled.

Specifically, the driving device 30 can select a servo motor, the rotation speed of the rotor of the servo motor is controlled by the input signal, and the response is fast, wherein the ac servo motor is suitable for the application of low-speed smooth operation. Before the silicon wafer leaves the surface of the water, the flower basket 10 containing the silicon wafer is driven to incline by a first angle so as to incline the silicon wafer to the side wall of the slot, and after the silicon wafer leaves the surface of the water, the flower basket 10 containing the silicon wafer is driven to incline by a second angle so as to increase the angle of the silicon wafer to incline to the side wall of the slot, wherein the first angle is smaller than the second angle.

That is to say, the first angle with a smaller angle can be selected before the silicon wafer leaves the surface of the water by the driving device 30, so that the cleaning effect is ensured, the silicon wafer can be dehydrated easily in the lifting process, the water hanging condition on the surface of the silicon wafer is reduced, the driving device 30 drives the inclined angle of the flower basket 10 containing the silicon wafer to be increased to a second angle after the silicon wafer leaves the surface of the water, so that the silicon wafer can read the tension of water at the bottom of the silicon wafer and the bottom 10 of the flower basket and is inclined towards the side wall of the slot, the contact area between the silicon wafer and the slot is reduced, the uniform dehydration of the silicon wafer is facilitated, and the problem that the silicon wafer. The change of the inclination angle of the flower basket 10 in water and on water is controlled to reduce the adhesion of large silicon wafers and the side walls of the slots due to the tension of water, so that the uniform dehydration of the silicon wafers is facilitated, and the yield of the silicon wafers is improved.

Preferably, the pulling device for single crystal texturing further comprises a controller (not shown). The controller is connected with the driving device 30, and controls the driving device 30 to drive the basket 10 containing the silicon wafers to incline by a first angle before the silicon wafers leave the surface of the water, and to drive the basket 10 containing the silicon wafers to incline by a second angle after the silicon wafers leave the surface of the water.

Further, the controller can set the time for pulling the flower basket to increase or decrease the slow pulling time, and the experimental data show that when the output set by the controller is 15Hz, namely the time for pulling the silicon wafer is 30s, the silicon wafer is more favorably and uniformly dehydrated. Further, when the second angle of the silicon wafer with the thickness of 170 μm and the control program sets the driving device 30 to be 21 °, the silicon wafer dehydration effect is optimal. With the subsequent progress of the slicing technology, after the cutting thickness of the silicon wafer is further reduced, the inclination angle of the flower basket 10 can be simply increased on the controller, and if the second angle is set to be 30 degrees, the contact area between the silicon wafer and the side wall of the slot is reduced.

That is to say, for silicon wafers with different thicknesses, adaptive matching parameters can be set in the controller according to the thicknesses of the silicon wafers with different thicknesses, so that the silicon wafers can be cleaned and dehydrated simply and efficiently in the cleaning process of the monocrystalline texturing silicon wafers, the contamination ratio of water wafers and texturing is obviously reduced, and the yield of the silicon wafers with different thicknesses is improved.

Preferably, when the thickness of the silicon wafer is 170 μm, the whitening rate of the textured edge of the silicon wafer is the lowest when the flower basket 10 is inclined at the first angle set to 0 °.

Preferably, when the thickness of the silicon wafer is 170 μm, the dehydration effect of the silicon wafer is the best when the second angle is 21 °.

Preferably, the pulling device for single crystal texturing further comprises a sensor, such as a liquid level sensor (not shown), the liquid level sensor is connected with the controller, and the liquid level sensor is used for monitoring whether the silicon wafer is away from the surface of water or not.

That is, the controller may determine whether the driving device 30 performs the slow pulling motion according to whether the flower basket 10 is inclined at the first angle or the second angle by reading data of the liquid level sensor.

Specifically, the slow pulling device for single crystal texturing performs the pulling method for single crystal texturing in the pulling process, which may specifically refer to the pulling method for single crystal texturing in the foregoing embodiment, and is not described herein again.

Therefore, the single crystal texturing pulling device provided by the embodiment of the invention is beneficial to uniform dehydration of a silicon wafer, reduces the problem of texturing and whitening of the edge of the silicon wafer, obviously reduces the dirty ratio of water pieces to texturing, and further improves the yield of the silicon wafer.

Other structures and operations of the pulling method and apparatus for single crystal texturing according to embodiments of the present invention will be understood and readily implemented by those skilled in the art, and therefore will not be described in detail.

The foregoing is a preferred embodiment of the present invention, and it should be noted that it is obvious to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and these modifications and improvements should be considered as the protection scope of the present invention.