WO2011039881A1

WO2011039881A1 - Positioning pin compatible with deformation caused by difference in coefficient of thermal expansion

Info

Publication number: WO2011039881A1
Application number: PCT/JP2009/067158
Authority: WO
Inventors: ジュンミンウ
Original assignee: 東京エレクトロン株式会社
Priority date: 2009-10-01
Filing date: 2009-10-01
Publication date: 2011-04-07
Also published as: TW201131082A; TWI498489B

Abstract

Disclosed is a positioning pin comprised of a first portion, a second portion, and a groove portion. The first portion is composed of a hollow cylindrical element. The second portion is composed of a hollow polygonal column element having a plurality of side surfaces, and is coaxially and integrally formed with the first portion. The side surfaces are comprised of a first side surface, a second side surface, and a third side surface. The first side surface is in parallel with the second side surface. The third side surface is positioned between the first side surface and the second side surface, and is perpendicular to the first side surface and the second side surface. The groove portion is continuously formed in the first portion and the second portion along the third portion, and penetrates through the first portion and the second portion.

Description

Positioning pin adaptable to deformation caused by difference in thermal expansion coefficient

The present invention relates to a positioning pin, and more particularly to a positioning pin that can be adapted to deformation caused by a difference in thermal expansion coefficient.

In the semiconductor plasma etching technology, a wafer to be processed is usually fixed by an electrostatic chuck (ESC). The electrostatic chuck is positioned by a positioning pin with respect to the focus ring and the lower quartz ring located below the focus ring. However, there are various electrostatic chucks, focus rings, and lower-layer quartz rings (hereinafter sometimes referred to as “members”) when the wafer is carried into and out of the etching chamber and during the etching period. Shifting due to the factor causes wafer arcing or electrostatic chuck arcing (ESC arcing). The factors of the shift can be roughly divided as follows. (1) Deviation occurs due to vacuum suction in the etching chamber. That is, the member is shifted due to a very large pressure difference at the moment when the atmosphere in the chamber is evacuated. (2) Deviation occurs due to a pressure difference between the wafer load lock module (LLM, load-lock module) and the etching chamber. That is, when the wafer transfer system passes the wafer through the wafer load lock module and carries it into the etching chamber, the wafer load lock module is first evacuated and the gate located between the wafer load lock module and the etching chamber. Is opened after the inside of the wafer load lock module is evacuated, and the wafer transfer system carries the wafer into the etching chamber. A pressure difference occurs at the moment when the gate is opened and closed, thereby causing a shift in the member. (3) Deviation occurs due to temperature change. That is, during the etching process, the temperature of the electrostatic chuck is repeatedly raised and lowered between about 0 ° C. and about 40 ° C., and each member has a different coefficient of thermal expansion, causing a shift in the member. In the conventional improvement method, the problem of deviation due to the pressure difference (that is, deviation due to the above (1) and (2)) has already been improved. For example, the method of reducing the pressure difference during vacuum suction by controlling the flow rate of the low vacuum throttle at the exhaust port of the etching chamber, or the wafer load lock module before opening the gate by changing the startup sequence and pressure sensor Improvements such as reducing the pressure difference between the etching chamber and the etching chamber have been made. However, the most fundamental problem, the shift due to the difference in the thermal expansion coefficient of each member (that is, the shift according to the above (3)) still remains. Therefore, there is an urgent need to develop a positioning pin that can eliminate the deviation caused by the difference in thermal expansion coefficient of each member.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a positioning pin capable of removing a shift caused by a difference in thermal expansion coefficient between members.

In order to achieve the above-described object, the present invention is a positioning pin, which is a first part that is a hollow cylindrical body and a hollow multi-sided pillar body having a plurality of side surfaces, and is integrally coaxially molded with the first part. The plurality of side surfaces have a first side surface, a second side surface, and a third side surface, the first side surface is parallel to the second side surface, and the third side surface is A second portion located between the first side surface and the second side surface and perpendicular to the first side surface and the second side surface; and the first portion along the third side surface; A groove portion formed continuously with the second portion and penetrating the first portion and the second portion;

The positioning pin of the present invention is used for an electrostatic chuck and a peripheral member thereof, and when the positioning pin is inserted into the electrostatic chuck and the peripheral member, the first portion becomes a circular pin hole of the electrostatic chuck. The first side surface and the second side surface of the second part can be in close contact with two opposite parallel long sides of the oval pin hole of the peripheral member. In addition, an oval is a shape which consists of two opposing parallel long sides which are linear, and two opposing short sides which curve outside in a semicircular shape.

Another aspect of the present invention is a positioning pin, a first portion that is a hollow cylindrical body,
A hollow polygonal column having a plurality of side surfaces, wherein the plurality of side surfaces have a first side surface, a second side surface, a third side surface, and a fourth side surface, of which the first The side surface is parallel to the second side surface, and the third side surface and the fourth side surface are located between the first side surface and the second side surface and the first side surface And a second portion perpendicular to the second side surface;
A hollow polygonal column having a plurality of side surfaces, integrally formed with the first part and the second part, and interposed between the first part and the plurality of side surfaces, A fifth side surface, a sixth side surface, a seventh side surface, and an eighth side surface, wherein the fifth side surface is parallel to the sixth side surface, the seventh side surface and the eighth side surface; Is located between the fifth side surface and the sixth side surface and is perpendicular to the fifth side surface and the sixth side surface, and the first side surface and the fifth side surface are coplanar The second side surface and the sixth side surface are coplanar, the third side surface and the seventh side surface are coplanar, and the fourth side surface and the eighth side surface are coplanar. A third part which is a plane;
The first portion, the second portion, and the third portion are formed continuously along the third side surface and the seventh side surface that are coplanar, and the first portion, the second portion, and the first portion A first groove passing through the three parts;
The second groove portion formed on the fourth side surface of the second portion, penetrating the second portion, and parallel to the first groove portion.
Each of the second groove portions can extend to the first portion and the third portion in the axial direction of the positioning pin. The first side surface and the fifth side surface may be non-coplanar, and the second side surface and the sixth side surface may be non-coplanar. Each of the second groove portions can extend to the first portion and the third portion in the axial direction of the positioning pin.

In another aspect, the positioning pin of the present invention is used for an electrostatic chuck and its peripheral member, and the peripheral member has a focus ring and a lower quartz ring, and the positioning pin includes the electrostatic chuck, the focus ring, and the When inserted into the lower quartz ring, the first portion is tightly inserted into the circular pin hole of the electrostatic chuck, and the first side surface and the second side surface of the second portion are each of the lower quartz ring. In close contact with two opposite parallel long sides of the oval pin hole, the fifth side surface and the sixth side surface of the third portion being respectively opposite the two oval pin holes of the focus ring In close contact with the parallel long sides.

According to the present invention, when a member is positioned using the positioning pin, a shift caused by a difference in thermal expansion coefficient between the members can be removed.

It is explanatory drawing which shows the state which the positioning pin performed positioning with respect to an electrostatic chuck, a focus ring, and a lower layer quartz ring. It is explanatory drawing which shows the state by which the conventional positioning pin was inserted in the oval pin hole of the focus ring. (A) is a three-dimensional view of a positioning pin according to an embodiment of the present invention, and (B) is a cross-sectional view taken along line YY in FIG. 3 (A). FIG. 3A is a cross-sectional view taken along line aa in FIG. 3A, and FIG. 3B is a cross-sectional view taken along line bb in FIG. It is explanatory drawing which shows the state by which the positioning pin based on embodiment of this invention was inserted in the oval pin hole of the focus ring. It is a three-dimensional view of a positioning pin based on another embodiment of the present invention. 6A is a front view of the positioning pin shown in FIG. 6, FIG. 6B is a rear view of the positioning pin shown in FIG. 6, and FIG. 6C is a sectional view taken along line ZZ in FIG. . 6A is a cross-sectional view taken along line a′-a ′ in FIG. 6, FIG. 6B is a cross-sectional view taken along line b′-b ′ in FIG. 6, and FIG. FIG. 6 is a cross-sectional view taken along c′-c ′.

DESCRIPTION OF SYMBOLS 1 Positioning pin 3 Electrostatic chuck 5 Focus ring 7 Lower layer quartz ring 51 Pin hole 51a Long side 51b Long side 100 Positioning pin 110 Groove 120 First side surface 120 'Second side surface 130 Third side surface 200 Positioning pin 210 First Groove 220 First surface 220 'Second surface 225 Third surface 225' Fourth surface 230 Fifth surface 230 'Sixth surface 235 Seventh surface 235' Eighth surface 240 Second groove A 1st part B 2nd part A '1st part B' 2nd part C '3rd part

Embodiments and advantages of the present invention will become apparent from the following and detailed description taken in conjunction with the drawings which illustrate the principles of the invention.

The exemplary embodiments of the present invention and the advantages and features of the embodiments will be described more clearly with reference to the accompanying drawings. Here, each drawing is merely an illustrative diagram, and is not drawn based on actual proportions, and is not based on the proportions shown in these drawings.

FIG. 1 is an explanatory view showing a state in which the electrostatic chuck 3, the focus ring 5 and the lower layer quartz ring 7 are positioned by the positioning pins 1. As shown in FIG. 1, when positioning is performed, the positioning pins 1 are simultaneously inserted into the pin holes of the electrostatic chuck 3, the focus ring 5 and the lower quartz ring 7. At this time, since the positioning pin 1 penetrates the lower quartz ring 7, the positioning range of the positioning pin 1 includes the three

members

3, 5, and 7. Generally, the positioning pin 1 is made of a polyimide material (for example, Vespel (registered trademark of EI DuPont de Nemours and Company) SP-1) or other suitable material. Is done. The electrostatic chuck 3 is made of aluminum. The focus ring 5 is made of silicon. The lower quartz ring 7 is made of quartz.

In the conventional plasma etching equipment, the pin holes of the electrostatic chuck 3 are circular, the pin holes of the focus ring 5 and the lower quartz ring 7 are both oval, and the outer shape of the positioning pin 1 is a solid cylindrical shape. . Among them, the positioning pin 1 is inserted completely tightly into the circular pin hole of the electrostatic chuck 3 (not shown), and other portions of the positioning pin 1 are oval pin holes (in the focus ring 5 and the lower quartz ring 7). 2) can be inserted simultaneously. FIG. 2 is an explanatory view showing a state in which the conventional positioning pin 1 is inserted into the oval pin hole 51 of the focus ring 5. As shown in FIG. 2, when the positioning pin 1 is inserted into the oval pin hole 51 of the focus ring 5, two opposite parallel

long sides

51 a and 51 b of the pin hole 51 are arranged on both circumferential sides of the positioning pin 1. The focus ring 5 is fixed in close contact. Similarly, the lower quartz ring 7 is also fixed by this method. However, since the operation of raising and lowering the temperature of the electrostatic chuck 3 is repeatedly performed during the plasma etching process, the electrostatic chuck 3, the focus ring 5, the lower quartz ring 7, and the positioning pin 1 are expanded and contracted due to temperature changes. Arise. Furthermore, since the electrostatic chuck 3 has a disk-like structure and the focus ring 5 and the lower quartz ring 7 have a ring-like structure, the deviation of thermal expansion in the normal direction of these

members

3, 5, 7 is It becomes even more significant compared to the volumetric thermal expansion shift. In addition, when thermal expansion occurs in the positioning pin 1 having a solid structure, the volume thermal expansion shift becomes more obvious. In such a situation, when thermal expansion occurs in the electrostatic chuck 3, the focus ring 5, the lower quartz ring 7 and the positioning pin 1, the volume thermal expansion shift of the positioning pin 1 is the

other members

3, 5, 7. Since this is not adaptable to the thermal expansion deviation of the positioning pin, damage to other members (particularly, damage to the focus ring 5), crushing of the positioning pin 1 itself, or dropping from the pin hole of the positioning pin 1 occurs, and the positioning effect is lost. Is called. Further, when the positioning pin 1 is closely inserted into the pin hole 51, the circumference of the positioning pin 1 and the

long sides

51a and 51b of the pin hole 51 are almost in line contact with each other, and therefore the contact area is small. Therefore, when plasma etching is performed, the plasma is very likely to enter the pin hole 51 and erodes the positioning pin 1, so that the

members

3, 5, and 7 are shifted. This phenomenon also shortens the service life of the positioning pin 1.

3A is a three-dimensional view of the positioning pin 100 according to the embodiment of the present invention, and FIG. 3B is a cross-sectional view taken along line YY in FIG. 3A. As shown in FIG. 3A and FIG. 3B, the positioning pin 100 has a first part A and a second part B which are integrally coaxially molded, and has a hollow structure and a groove part 110, whereby “C A positioning effect is obtained by the spring tension forming a mold structure. Of these, the groove 110 may form an opening of this “C” type structure. 4A is a cross-sectional view taken along line aa in FIG. 3A, and shows a cross section of the first portion A. FIG. 4B is a cross-sectional view taken along the line bb in FIG. 3A, and shows a cross section of the second portion B. FIG. The first part A is a hollow cylinder. When the positioning pin 100 is inserted into the electrostatic chuck 3, the first portion A is tightly inserted into the circular pin hole of the electrostatic chuck 3. The second part B is a hollow polygonal column and has a plurality of side surfaces. On these side surfaces of the second part B, the first side surface 120 and the second side surface 120 ′ (FIG. 4B) facing and parallel to each other have the positioning pin 100 in the focus ring 5 and the lower quartz ring 7. When inserted, it is in close contact with the two opposite parallel long sides of the oval pin hole of the focus ring 5 and the lower quartz ring 7, respectively, and accepts the deviation of normal thermal expansion and cooling shrinkage. And the gap between the circumferences can be minimized. Specifically, as shown in FIG. 5, when the focus ring 5 is taken as an example, when the positioning pin 100 is inserted into the pin hole 51 of the focus ring 5, the first side surface 120 and the second portion B of the second part B The side surface 120 ′ can be in intimate contact with two opposing parallel

long sides

51 a and 51 b of the pin hole 51, respectively. The situation of the lower quartz ring 7 is the same as described above. In addition, the groove portion 110 is formed continuously from the first portion A and the second portion B along the other third side surface 130 between the first side surface 120 and the second side surface 120 ′. A and the second part B are penetrated. Also, the third side surface 130 is perpendicular to the first side surface 120 and the second side surface 120 '.

Since the positioning pin 100 has a hollow structure and the groove portion 110, when thermal expansion / cooling / shrinkage occurs in the electrostatic chuck 3, the focus ring 5, and the lower layer quartz ring 7, the positioning pin 100 is connected to the

members

3, 5, 7. Adapts to deformation due to differences in thermal expansion coefficient and reduces shift due to deformation. Here, when the positioning pin has a solid structure, the entire volume of the positioning pin changes depending on the temperature during the thermal expansion / cooling / shrinkage, so that the deformation cannot be applied to the

other members

3, 5, 7. However, since the positioning pin 100 has the hollow structure and the groove 110, the form of thermal expansion is changed from volumetric thermal expansion to linear thermal expansion, and can be applied to deformations occurring in the

other members

3, 5, and 7. . Further, the contact between the first side surface 120 and the second side surface 120 'of the second portion B of the positioning pin 100 and the

long sides

51a and 51b changes from line contact to surface contact. At this time, the contact area is larger than the contact area of the line contact, and therefore, it is difficult for plasma to enter the pin holes of each member during plasma etching, thereby extending the service life of the positioning pin 100 and the other members 3. 5 and 7 are prevented from being damaged by thermal expansion of the positioning pin 100. The single positioning pin 100 performs circumferential positioning. When three or more positioning pins 100 are arranged at equal intervals on the same circumference of the electrostatic chuck 3, the focus ring 5 and the lower quartz ring 7, the normal direction due to thermal expansion or cooling contraction can be obtained. In response to the deviation, a positioning effect is produced for the

members

3, 5, 7.

FIG. 6 is a three-dimensional view of a positioning pin 200 according to another embodiment of the present invention. 7A is a front view of the positioning pin 200 shown in FIG. 6, FIG. 7B is a rear view of the positioning pin 200 shown in FIG. 6, and FIG. 7C is FIG. FIG. 6 is a sectional view taken along line ZZ. As shown in FIGS. 6 to 7C, the positioning pin 200 has a first portion A ′, a second portion B ′, and a third portion C ′ that are integrally coaxially molded, and has a hollow structure and a first groove portion 210. And a second groove portion 240. FIG. 8A is a cross-sectional view taken along line a′-a ′ in FIG. 6 and shows a cross section of the first portion A ′. FIG. 8B is a cross-sectional view taken along line b′-b ′ in FIG. 6 and shows a cross section of the second portion B ′. FIG. 8C is a cross-sectional view taken along the line c′-c ′ in FIG. 6 and shows a cross section of the third portion C ′. Like the positioning pin 100, the positioning pin 200 also has a “C” -type structure, and the first groove portion 210 may form an opening of this type of “C” -type structure, and a positioning effect is obtained by spring tension. . The first part A 'is a hollow cylinder. When the positioning pin 200 is inserted into the electrostatic chuck 3, the first portion A ′ is tightly inserted into the circular pin hole of the electrostatic chuck 3. The second portion B 'is a hollow polygonal column and has a plurality of side surfaces. On these side surfaces of the second part B ′, the opposing parallel first side surface 220 and second side surface 220 ′ are respectively the lengths of the lower quartz ring 7 when the positioning pin 200 is inserted into the lower quartz ring 7. Close contact with two opposite parallel long sides of the circular pin hole (similar to FIG. 5). There are a parallel third side surface 225 and a fourth side surface 225 ′ opposite to each other between the first side surface 220 and the second side surface 220 ′, and the third side surface 225 and the fourth side surface 225 ′ are the first side surface 225 ′. It is perpendicular to the side surface 220 and the second side surface 220 ′. The third portion C ′ is also a hollow polygonal column and has a plurality of side surfaces. On these side surfaces of the first portion C ′, the opposite parallel fifth side surface 230 and sixth side surface 230 ′ are respectively oblong pin holes of the focus ring 5 when the positioning pin 200 is inserted into the focus ring 5. In close contact with two opposite parallel long sides (similar to FIG. 5). Between the fifth side surface 230 and the sixth side surface 230 ′, there are parallel seventh side surface 235 and eighth side surface 235 ′ opposite to each other, and the seventh side surface 235 and the eighth side surface 235 ′ are the first side surface 235 ′. It is perpendicular to the fifth side surface 230 and the sixth side surface 230 ′.

The first side surface 220 and the fifth side surface 230 may be either a coplanar surface or a non-coplanar surface. The second side surface 220 'and the sixth side surface 230' may be either coplanar or non-coplanar. In FIG. 6, the first side surface 220 and the fifth side surface 230 are non-coplanar, and the second side surface 220 'and the sixth side surface 230' are also non-coplanar. That is, there is a step between the first side surface 220 and the fifth side surface 230, and there is also a step between the second side surface 220 'and the sixth side surface 230'. The third side surface 225 and the seventh side surface 235 are coplanar, and the fourth side surface 225 'and the eighth side surface 235' are coplanar. In another embodiment of the invention, the first side surface 220 and the fifth side surface 230 are coplanar, and the second side surface 220 'and the sixth side surface 230' are also coplanar. That is, there is no step between the first side surface 220 and the fifth side surface 230, and there is no step between the second side surface 220 'and the sixth side surface 230'. The first groove portion 210 is formed continuously with the first portion A ′, the second portion B ′, and the third portion C ′ along the coplanar third surface 225 and the seventh surface 235, and the first portion A ′. , Through the second part B ′ and the third part C ′. The second groove part 240 is formed on the fourth side surface 225 ′ of the second part B ′, passes through the second part B ′, and the first groove part 210 is parallel to the second groove part 240. In addition, the second groove portion 240 also extends in the axial direction of the positioning pin 200 to the columnar body of the first portion A ′ and the eighth side surface 235 ′ of the third portion C ′, respectively. A groove portion penetrating in a part of 235 ′ is formed.

Since the positioning pin 200 has a hollow structure and the first groove portion 210, the thermal expansion form changes from volume thermal expansion to linear thermal expansion, and can be adapted to deformation occurring in the

other members

3, 5, and 7. is there. In addition, since the second portion B ′ of the positioning pin 200 has the second groove portion 240, the second portion B ′ itself has the function of a plate spring, and the adaptability to deformation of the positioning pin 200 is improved. To do. The positioning pins 200 are also positioned in the semiconductor plasma etching facility by the arrangement method of the positioning pins 100, for example. Further, on the same circumference of the electrostatic chuck 3, the focus ring 5 and the lower layer quartz ring 7, three or more positioning pins 200 may be arranged on this circumference at equal intervals. In this case, a shift effect in the normal direction due to thermal expansion or cooling shrinkage is received, and a positioning effect is generated for the

members

3, 5, 7.

In addition, the positioning pins of the present invention are not only used in semiconductor plasma etching equipment, but also other techniques that require positioning, such as positioning of members, structures, etc. that cause deviation due to differences in thermal expansion coefficients. Applicable to fields. For example, the positioning pin of the present invention may be used at a joint location of a bridge or a building, or may be applied to joint positioning of a motor vehicle component.

Although the present invention has been described in detail with reference to the embodiments and drawings, various improvements, changes, and substitutions of equivalent effects can be made by those who have ordinary knowledge in the field of the present invention without exceeding the essence and scope of the present invention. However, these improvements, changes and substitutions of equivalent effects are still within the scope of the claims of the present invention.

The present invention is useful for positioning members having different thermal expansion coefficients.

Claims

A positioning pin,
A first portion that is a hollow cylinder,
A hollow polygonal column having a plurality of side surfaces, integrally molded with the first portion, the plurality of side surfaces having a first side surface, a second side surface and a third side surface; The one side surface is parallel to the second side surface, the third side surface is located between the first side surface and the second side surface, and the first side surface and the second side surface A second part that is perpendicular to the side surface;
A groove formed continuously with the first part and the second part along the third side surface, and passing through the first part and the second part;
Have
The positioning pin according to claim 1,
The positioning pin is used for an electrostatic chuck and a peripheral member thereof, and the first portion is tightly fitted into a circular pin hole of the electrostatic chuck by inserting the positioning pin into the electrostatic chuck and the peripheral member. And the first side surface and the second side surface of the second portion are in close contact with two opposite parallel long sides of the oval pin hole of the peripheral member,
At least three positioning pins are installed at equal intervals on the same circumference of the electrostatic chuck and the peripheral member.
The positioning pin according to claim 2,
The peripheral member has a focus ring and a lower quartz ring.
A positioning pin,
A first portion that is a hollow cylinder,
A hollow polygonal column having a plurality of side surfaces, wherein the plurality of side surfaces have a first side surface, a second side surface, a third side surface, and a fourth side surface, and the first side The surface is parallel to the second side surface, the third side surface and the fourth side surface are located between the first side surface and the second side surface, and the first side A second portion that is perpendicular to the surface and said second side surface;
A hollow polygonal column having a plurality of side surfaces, which is integrally formed with the first part and the second part, and the plurality of side surfaces are interposed between the second part and the first part. Has a fifth side surface, a sixth side surface, a seventh side surface and an eighth side surface, and the fifth side surface is parallel to the sixth side surface, and the seventh side surface and the The eighth side surface is located between the fifth side surface and the sixth side surface and is perpendicular to the fifth side surface and the sixth side surface, and the first side surface and the fifth side surface are The second side surface and the sixth side surface are coplanar, the third side surface and the seventh side surface are coplanar, the fourth side surface and the eighth side surface. Is a third part that is coplanar,
Along the third surface and the seventh surface that are coplanar, the first portion, the second portion, and the third portion are formed continuously, and the first portion, the second portion, and the A first groove passing through the third portion;
A second groove part formed on the fourth side surface of the second part, penetrating the second part, and facing and parallel to the first groove part;
Have
The positioning pin according to claim 4,
The positioning pin is used for an electrostatic chuck and its peripheral member. The peripheral member has a focus ring and a lower layer quartz ring, and the positioning pin is inserted into the electrostatic chuck, the focus ring and the lower layer quartz ring. Thus, the first part is tightly inserted into the circular pin hole of the electrostatic chuck, and the first side surface and the second side surface of the second part are respectively the oval pin hole of the lower quartz ring. Two opposing parallel long sides in close contact with two opposing parallel long sides, and wherein the fifth side surface and the sixth side surface of the third portion are each an oval pin hole of the focus ring. In close contact with
At least three positioning pins are installed at equal intervals on the same circumference of the electrostatic chuck and the peripheral member.
The positioning pin according to claim 4,
The first side surface and the fifth side surface are non-coplanar, and the second side surface and the sixth side surface are non-coplanar.
The positioning pin according to claim 4,
Each of the second groove portions can extend to the first portion and the third portion in the axial direction of the positioning pin.
The positioning pin according to claim 6,
Each of the second groove portions can extend to the first portion and the third portion in the axial direction of the positioning pin.