CN112809455A - Tungsten silicon target material and polishing method of sputtering surface thereof - Google Patents

Abstract

The invention provides a tungsten silicon target and a polishing method of a sputtering surface thereof, wherein the polishing method comprises a first water mill polishing, a second water mill polishing and a third water mill polishing which are carried out back and forth; the number of round trips is 15-25; the running speeds of the target materials of the first water mill polishing, the second water mill polishing and the third water mill polishing are respectively and independently 0.1-0.3m/s and are respectively and independently carried out by adopting water mill abrasive belts; the rotating speed of the water grinding abrasive belt is 10-30r/min, and the specification comprises a No. 600 white corundum abrasive belt or a No. 800 white corundum abrasive belt; the first water mill polishing, the second water mill polishing and the third water mill polishing are respectively and independently accompanied with cooling water to flush the sputtering surface of the target; the flushing rate of the cooling water is 600-800mL/min, and the temperature is 5-25 ℃. The polishing method greatly reduces the roughness of the sputtering surface of the target, avoids the cracking phenomenon of the target, reduces the production cost and is easy to popularize and apply.

Description

Tungsten silicon target material and polishing method of sputtering surface thereof

Technical Field

The invention belongs to the technical field of sputtering targets, relates to a polishing method, and particularly relates to a tungsten silicon target and a polishing method of a sputtering surface thereof.

Background

The sputtering target is a sputtering source which forms various functional films on a substrate by sputtering through a coating system of magnetron sputtering under proper process conditions. The surface roughness of the sputtering target has a significant influence on the sputtering effect, and when irregularities exceeding a certain level in size or protrusions exist on the surface of the target, abnormal discharge may occur on the protrusions. The abnormal discharge may cause large particles to be sputtered from the target surface and deposited on the silicon wafer, even forming spots on the thin film and causing short-circuiting of the semiconductor thin film circuit.

The high-purity tungsten silicon target has the characteristics of hardness (the hardness is more than 1300 HV), and the surface of the target is difficult to polish by conventional abrasive paper, scouring pad and other modes to reduce the roughness; and after welding with the back plate, the grinding wheel is deformed to a certain degree due to heating, so that the problem of cracking is easily caused by using the grinding wheel, the grinding wheel is inconvenient to replace, the mesh number is less, and the further reduction of the roughness of the sputtering surface of the target is limited.

CN103695852a discloses a method for manufacturing a tungsten silicon target, comprising: (1) providing high-purity tungsten powder and high-purity silicon powder; (2) mixing tungsten powder and silicon powder by adopting a wet mixing process to form mixed powder; (3) preparing the mixed powder into a tungsten-silicon target blank by adopting a cold pressing process; (4) and preparing the tungsten-silicon target blank into a tungsten-silicon target by adopting a vacuum hot pressing process. The preparation process disclosed by the invention has the advantages of few steps and high production speed, the tungsten silicon target with the density not lower than 99% is obtained, the microstructure of the tungsten silicon target is uniform, and the tungsten silicon target has excellent sputtering service performance. However, the invention does not provide a method for polishing the sputtering surface of the target, and therefore, the target cannot be directly used for magnetron sputtering.

CN 111300157a discloses a surface treatment method of a high-hardness target, which comprises the following steps: (1) carrying out primary grinding treatment on the sputtering surface of the target to obtain a rough machining target; (2) and (3) carrying out secondary grinding treatment on the sputtering surface of the rough machining target obtained in the step (1). The first grinding treatment and the second grinding treatment are respectively and independently carried out under the condition of adding cutting fluid. According to the invention, the surface of the target material is treated by two independent grinding treatments, and the roughness Ra of the target material after the surface treatment is reduced to below 0.4 by selecting a proper cutting fluid composition and a proper amount of the cutting fluid, so that the abrasion of the grinding head is slowed down, and the service life of the grinding head is prolonged. However, the process flow of the invention is complex, the requirement on the composition of the cutting fluid is high, the processing cost is increased, and the large-scale popularization and application are not facilitated.

Therefore, how to provide a polishing method for the sputtering surface of the tungsten-silicon target, which can greatly reduce the roughness of the sputtering surface of the target, avoid the target from cracking, reduce the production cost, is easy to popularize and apply and becomes a problem to be solved by technical personnel in the field at present.

Disclosure of Invention

The invention aims to provide a tungsten silicon target and a polishing method of a sputtering surface thereof, which greatly reduce the roughness of the sputtering surface of the target, avoid the cracking phenomenon of the target, reduce the production cost and are easy to popularize and apply.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the invention provides a polishing method for a tungsten-silicon target sputtering surface, which comprises a first water mill polishing, a second water mill polishing and a third water mill polishing which are carried out back and forth.

In the invention, the first water grinding polishing, the second water grinding polishing and the third water grinding polishing are sequentially carried out in a single round trip, so that the roughness of the sputtering surface of the target material is greatly reduced, and the target material is prevented from cracking in the polishing process.

Preferably, the number of round trips is 15-25, and may be, for example, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 or 25, but is not limited to the recited values, and other values not recited in the range of values are also applicable.

In the invention, the reciprocating step is to sequentially carry out first water grinding polishing, second water grinding polishing, third water grinding polishing, second water grinding polishing and first water grinding polishing; and after 1 cycle of the first water mill polishing, the second water mill polishing, the third water mill polishing, the second water mill polishing and the first water mill polishing is completed, recording as the completion of 1 round trip.

In the invention, the target with a bright surface can be obtained after the water grinding and polishing are carried out for 15-25 times, the problem of insufficient polishing exists when the number of times is less than 15, and the unnecessary prolonging of the processing time is caused when the number of times is more than 25.

Preferably, the target running speeds of the first water mill polishing, the second water mill polishing and the third water mill polishing are 0.1-0.3m/s, such as 0.1m/s, 0.12m/s, 0.14m/s, 0.16m/s, 0.18m/s, 0.2m/s, 0.22m/s, 0.24m/s, 0.26m/s, 0.28m/s or 0.3m/s, but not limited to the enumerated values, and other non-enumerated values in the numerical range are also applicable.

In the invention, the target material running speed needs to be kept at a moderate level, the speed is lower than 0.1m/s, which causes unnecessary prolonging of processing time, and the speed is higher than 0.3m/s, which causes the problem of insufficient polishing.

Preferably, the first water mill polishing, the second water mill polishing and the third water mill polishing are respectively and independently performed by using water mill abrasive belts.

Preferably, the rotational speed of the abrasive belt is 10-30r/min, such as 10r/min, 12r/min, 14r/min, 16r/min, 18r/min, 20r/min, 22r/min, 24r/min, 26r/min, 28r/min or 30r/min, but is not limited to the values listed, and other values not listed in this range are equally applicable.

In the invention, the rotating speed of the water grinding abrasive belt needs to be kept at a moderate level, the rotating speed is lower than 10r/min, the insufficient polishing and the unnecessary extension of the processing time are easily caused, and the target cracking risk exists when the rotating speed is higher than 30 r/min.

Preferably, the specification of the water-milled abrasive belt comprises a 600# white corundum abrasive belt or a 800# white corundum abrasive belt.

According to the invention, the specification of the water-grinding abrasive belt has an obvious influence on the polishing effect of the sputtering surface of the target, and the size of the sand grains on the surface of the No. 600 white corundum abrasive belt or the No. 800 white corundum abrasive belt is between 600 and 800 meshes, so that the roughness of the sputtering surface of the target can be greatly reduced, the target is prevented from cracking, and the polishing effect and the safety are improved.

Preferably, the first water mill polishing, the second water mill polishing and the third water mill polishing are respectively and independently accompanied with cooling water to flush the sputtering surface of the target.

Preferably, the flushing rate of the cooling water is 600-800mL/min, such as 600mL/min, 620mL/min, 640mL/min, 660mL/min, 680mL/min, 700mL/min, 720mL/min, 740mL/min, 760mL/min, 780mL/min or 800mL/min, but is not limited to the recited values, and other values not recited in the range are equally applicable.

Preferably, the cooling water has a temperature of 5 to 25 ℃, for example 5 ℃, 10 ℃, 15 ℃, 20 ℃ or 25 ℃, but is not limited to the recited values, and other values not recited within the range of values are equally applicable.

According to the invention, the cooling water flushes the sputtering surface of the target, on one hand, impurities remained after the surface of the target is polished are removed in time, on the other hand, the cooling effect is exerted on the sputtering surface of the target, and the target is prevented from cracking due to overhigh temperature.

As a preferable technical solution of the first aspect of the present invention, the polishing method includes a first water mill polishing, a second water mill polishing, and a third water mill polishing performed back and forth; the number of round trips is 15-25.

The running speeds of the target materials of the first water mill polishing, the second water mill polishing and the third water mill polishing are respectively and independently 0.1-0.3m/s and are respectively and independently carried out by adopting water mill abrasive belts; the rotating speed of the water grinding abrasive belt is 10-30r/min, and the specification comprises a No. 600 white corundum abrasive belt or a No. 800 white corundum abrasive belt.

The first water mill polishing, the second water mill polishing and the third water mill polishing are respectively and independently accompanied with cooling water to flush the sputtering surface of the target; the flushing rate of the cooling water is 600-800mL/min, and the temperature is 5-25 ℃.

Compared with the prior art, the invention has the following beneficial effects:

the polishing method provided by the invention can reduce the roughness of the sputtering surface of the target material to 0.311 mu m, simultaneously avoids the cracking phenomenon of the target material and has good safety; in addition, the polishing method reduces the production cost and is easy to popularize and apply on a large scale.

Drawings

FIG. 1 is a schematic view of an apparatus used in the polishing method of a tungsten-silicon target sputtering surface provided by the invention.

Wherein: 1-sputtering surface of target material; 2-first water grinding and polishing; 3-second water grinding and polishing; and 4-third water grinding and polishing.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Example 1

The present embodiment provides a tungsten silicon target and a polishing method of a sputtering surface thereof, as shown in fig. 1, the polishing method is a first water mill polishing 2, a second water mill polishing 3 and a third water mill polishing 4, which are performed back and forth on the tungsten silicon target manufactured by the manufacturing method disclosed in CN103695852 a; the number of round trips is 20.

In the embodiment, the target material running speeds of the first water grinding polishing 2, the second water grinding polishing 3 and the third water grinding polishing 4 are respectively and independently 0.2m/s and are respectively and independently performed by using water grinding abrasive belts; the rotating speed of the water grinding abrasive belt is 20r/min, and the specification of the water grinding abrasive belt is a No. 600 white corundum abrasive belt.

In this embodiment, the first water-milling polishing 2, the second water-milling polishing 3, and the third water-milling polishing 4 are independently washed with the target sputtering surface 1 with cooling water respectively; the flushing rate of the cooling water is 700mL/min, and the temperature is 15 ℃.

The roughness and polishing effect of the sputtering surface of the tungsten silicon target material obtained in this example are shown in table 1.

Example 2

The present embodiment provides a tungsten silicon target and a polishing method of a sputtering surface thereof, as shown in fig. 1, the polishing method is a first water mill polishing 2, a second water mill polishing 3 and a third water mill polishing 4, which are performed back and forth on the tungsten silicon target manufactured by the manufacturing method disclosed in CN103695852 a; the number of round trips is 15.

In the embodiment, the target material running speeds of the first water grinding polishing 2, the second water grinding polishing 3 and the third water grinding polishing 4 are respectively and independently 0.1m/s and are respectively and independently performed by using water grinding abrasive belts; the rotating speed of the water grinding abrasive belt is 10r/min, and the specification of the water grinding abrasive belt is 800# white corundum abrasive belt.

In this embodiment, the first water-milling polishing 2, the second water-milling polishing 3, and the third water-milling polishing 4 are independently washed with the target sputtering surface 1 with cooling water respectively; the flushing rate of the cooling water is 600mL/min, and the temperature is 5 ℃.

The roughness and polishing effect of the sputtering surface of the tungsten silicon target material obtained in this example are shown in table 1.

Example 3

The present embodiment provides a tungsten silicon target and a polishing method of a sputtering surface thereof, as shown in fig. 1, the polishing method is a first water mill polishing 2, a second water mill polishing 3 and a third water mill polishing 4, which are performed back and forth on the tungsten silicon target manufactured by the manufacturing method disclosed in CN103695852 a; the number of round trips is 25.

In the embodiment, the target material running speeds of the first water grinding polishing 2, the second water grinding polishing 3 and the third water grinding polishing 4 are respectively and independently 0.3m/s and are respectively and independently performed by using water grinding abrasive belts; the rotating speed of the water grinding abrasive belt is 30r/min, and the specification of the water grinding abrasive belt is a No. 600 white corundum abrasive belt.

In this embodiment, the first water-milling polishing 2, the second water-milling polishing 3, and the third water-milling polishing 4 are independently washed with the target sputtering surface 1 with cooling water respectively; the flushing rate of the cooling water is 800mL/min, and the temperature is 25 ℃.

The roughness and polishing effect of the sputtering surface of the tungsten silicon target material obtained in this example are shown in table 1.

Example 4

This embodiment provides a polishing method for a tungsten silicon target and a sputtering surface thereof, wherein the polishing method is the same as that of embodiment 1 except that the polishing is performed back and forth 10 times, and therefore, the details are not repeated herein.

The roughness and polishing effect of the sputtering surface of the tungsten silicon target material obtained in this example are shown in table 1.

Example 5

This embodiment provides a tungsten silicon target and a polishing method for a sputtering surface thereof, in which the conditions are the same as those in embodiment 1 except that the target running speed is 0.5m/s, and thus details are not described herein.

The roughness and polishing effect of the sputtering surface of the tungsten silicon target material obtained in this example are shown in table 1.

Example 6

The present embodiment provides a tungsten-silicon target and a polishing method for a sputtering surface thereof, wherein the conditions except that the rotation speed of a water-milled abrasive belt is 8r/min are the same as those in embodiment 1, and therefore, the details are not repeated herein.

The roughness and polishing effect of the sputtering surface of the tungsten silicon target material obtained in this example are shown in table 1.

Example 7

The present embodiment provides a tungsten-silicon target and a polishing method for a sputtering surface thereof, wherein the conditions except that the rotation speed of a water-milled abrasive belt is 35r/min are the same as those in embodiment 1, and therefore, the details are not repeated herein.

The roughness and polishing effect of the sputtering surface of the tungsten silicon target material obtained in this example are shown in table 1.

Example 8

The present embodiment provides a tungsten-silicon target and a polishing method for a sputtering surface thereof, wherein the conditions of the polishing method are the same as those of embodiment 1 except that the specification of the water-milled abrasive belt is 400# white corundum abrasive belt, and therefore, the details are not repeated herein.

The roughness and polishing effect of the sputtering surface of the tungsten silicon target material obtained in this example are shown in table 1.

Comparative example 1

The polishing method comprises the steps of performing first grinding wheel polishing, second grinding wheel polishing and third grinding wheel polishing on the tungsten silicon target manufactured by the manufacturing method disclosed by CN103695852A back and forth; (ii) a The number of round trips is 20.

In the comparative example, the running speeds of the target materials for the first grinding wheel polishing, the second grinding wheel polishing and the third grinding wheel polishing are respectively and independently 0.2m/s and are respectively and independently carried out by adopting a fine grinding wheel; the rotating speed of the fine grinding wheel is 20r/min, and the specification of sand grains is 600 meshes.

The roughness and polishing effect of the sputtering surface of the tungsten-silicon target material obtained in the comparative example are shown in table 1.

Comparative example 2

The polishing method is to manually polish the tungsten silicon target manufactured by the manufacturing method disclosed in CN103695852A for 40min by using sand paper and scouring pad.

The roughness and polishing effect of the sputtering surface of the tungsten-silicon target material obtained in the comparative example are shown in table 1.

TABLE 1

Tungsten silicon target material	Roughness (μm)	Polishing effect
			Example 1	0.311	Good effect
Examples2	0.408	Good effect
			Example 3	0.574	Good effect
Example 4	0.873	Qualified
			Example 5	0.795	Qualified
Example 6	0.783	Qualified
			Example 7	0.563	Slight cracking
Example 8	0.894	Slight cracking
			Comparative example 1	0.901	Apparent cracking
Comparative example 2	2.479	Fail to be qualified

The roughness detection method comprises the following steps: using a surface roughness tester (equipment model: Japan Sanfeng SJ-210) to detect roughness, placing a sensor on a target sputtering surface during detection, uniformly taking 3 points at the center and the edge respectively, and calculating a reading average value to obtain the roughness of the sputtering surface; the polishing effect judging method comprises the following steps: observing the sputtering surface facing the target, wherein the outline of the five sense organs of the shadow is distinguished to be 'good'; the silhouettes can only be respectively qualified; the shadow outline can not be respectively unqualified; cracks were observed as "slight cracking" only within 1 meter; cracks were observed as "visible cracks" outside the 1 meter range.

As can be seen from Table 1, the roughness of the sputtering surface of the tungsten silicon target material obtained in examples 1 to 3 was as low as 0.311 μm, and the polishing effect was good; examples 4-6 show that too few target material reciprocating times, too fast running speed and too low rotational speed of the water mill abrasive belt can affect the polishing effect; examples 7 and 8 show that the target material slightly cracks in the polishing process due to the fact that the rotating speed of the water grinding abrasive belt is too high and the specification is unqualified; compared with the prior art, the target material is easy to crack by adopting the grinding wheel for polishing, the grinding wheel is inconvenient to replace, the mesh number is less, and the further reduction of the roughness of the sputtering surface of the target material is limited; comparative example 2 manual polishing using sandpaper and scouring pad was difficult to achieve the polishing effect and consumed a lot of manpower.

Therefore, the roughness of the sputtering surface of the target can be reduced to 0.311 mu m by the polishing method provided by the invention, the target is prevented from cracking, and the polishing method has good safety; in addition, the polishing method reduces the production cost and is easy to popularize and apply on a large scale.

The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope and disclosure of the present invention.

Claims (10)

1. The polishing method of the tungsten-silicon target sputtering surface is characterized by comprising a first water grinding polishing, a second water grinding polishing and a third water grinding polishing which are carried out back and forth.

2. The polishing method as set forth in claim 1, wherein the number of round trips is 15 to 25.

3. The polishing method according to claim 1 or 2, wherein the target running speeds of the first water mill polishing, the second water mill polishing and the third water mill polishing are respectively and independently 0.1 to 0.3 m/s.

4. The polishing method according to any one of claims 1 to 3, wherein the first water-jet polishing, the second water-jet polishing and the third water-jet polishing are each independently performed using a water-jet sanding belt.

5. The polishing method as claimed in claim 4, wherein the rotational speed of the watermill sanding belt is 10-30 r/min.

6. The polishing method according to claim 4 or 5, wherein the specification of the water-milled abrasive belt comprises a 600# white corundum abrasive belt or an 800# white corundum abrasive belt.

7. The polishing method according to any one of claims 1 to 6, wherein the first water-jet polishing, the second water-jet polishing and the third water-jet polishing are each independently accompanied by flushing the target sputtering surface with cooling water.

8. The polishing method as claimed in claim 7, wherein the washing rate of the cooling water is 600-;

preferably, the temperature of the cooling water is 5-25 ℃.

9. The polishing method according to any one of claims 1 to 8, comprising a first water buff polishing, a second water buff polishing and a third water buff polishing which are carried out back and forth; the number of round trips is 15-25;

the running speeds of the target materials of the first water mill polishing, the second water mill polishing and the third water mill polishing are respectively and independently 0.1-0.3m/s and are respectively and independently carried out by adopting water mill abrasive belts; the rotating speed of the water grinding abrasive belt is 10-30r/min, and the specification comprises a No. 600 white corundum abrasive belt or a No. 800 white corundum abrasive belt;

the first water mill polishing, the second water mill polishing and the third water mill polishing are respectively and independently accompanied with cooling water to flush the sputtering surface of the target; the flushing rate of the cooling water is 600-800mL/min, and the temperature is 5-25 ℃.

10. A tungsten silicon target polished by the polishing method as set forth in any one of claims 1 to 9.

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