TWI732447B - Scan robot for semiconductor wafer ion implantation - Google Patents

Abstract

The present invention relates to a semiconductor wafer ion implantation scanning robot, which includes: an L1 axis, which is vertically coupled to one side of a first connecting rod, and drives the first connecting rod to rotate by the driving of the first driving unit; the L2 axis is at The upper part of the first link is stacked with a second link whose length is the same as that of the first link, and the second link is vertically connected to the other side of the first link and the second link stacked on it. One side of the connecting rod is driven by the second driving unit to drive the second connecting rod to rotate; the R-axis is stacked on the upper part of the other side of the second connecting rod to support the support frame for the scanning head, which is vertically combined with The other side of the second link and the center of the support frame are driven by the third drive unit to drive the support frame to rotate; and the Y axis is horizontally coupled to the support frame and supports the scanning head The scanning head is driven to rotate by the driving of the fourth driving unit. According to the embodiment of the present invention, the scalar motion that can be scanned in any designated direction in the horizontal direction is realized through the actions of the L1 axis and the L2 axis, and the adjustment is made through the action of the R axis to keep the ion beam constant during the left and right scans. Through the S-axis of incident angle, the action of the S-axis can prevent the beam channel effect and prevent the shadow phenomenon according to the crystal direction of the wafer, and can also improve the uniformity of ion beam implantation on the wafer. Moreover, even during high-inclination low-energy ion implantation, the entire area on the wafer can be irradiated by equidistant sub-beams, which greatly improves the uniformity of doping on the wafer. Doping uniformity requires conditions.

Description

Semiconductor wafer ion implantation scanning robot

Field of invention

The present invention relates to a semiconductor wafer ion implantation scanning robot. More specifically, the semiconductor wafer ion implantation scanning robot can scan the wafer in any designated direction in the horizontal direction during the ion implantation process of the semiconductor wafer to be implanted on the wafer. The ions are uniformly distributed.

Background of the invention

The semiconductor device manufacturing process usually repeats an oxidation process, a photographic etching process, a diffusion process, an ion implantation process, and a metal process on a silicon wafer.

The ion implantation process in the manufacturing process refers to injecting impurities charged according to a preset energy into the wafer according to the required amount and the required depth. In the semiconductor manufacturing process, the ion implantation process usually refers to implanting dopant ions on the surface of the silicon wafer.

The ion implanter used in the ion implantation process mainly includes the following three parts.

The main part can be divided into: the field of ion source (Ion Source) as the field of extracting ion beam (Ion Beam); including the mass analyzer (Mass Analyzer) that classifies the extracted ion beam according to the required quality and the field of ion beam The terminal area of the beamline of the path; the end-station area where the wafer is transferred and the ion beam is finally implanted.

In the field of End-Station, scanning wafers in a high-vacuum process chamber And implant ion beam.

Figure 1 is the most representative example of the previous wafer beam scanning method. An air bearing (Air Bearing) 10 is installed at the lower end of a high-vacuum process chamber and the up and down movement in the mechanism is performed, so as to be relative to the horizontal The ribbon ion beam (Parallel Ribbon Beam) or the horizontal scanning ion beam (Parallel Scanned Beam) performs ion implantation in a vertical direction for mechanical scanning (Mechanical Scanning).

The following tilt (Tilt) method is adopted, that is, the process is performed within a certain time after the wafer is tilted at a certain angle with respect to the ion beam according to the type of components to be formed on the wafer. Therefore, the ion implantation process needs to have the ability to adjust the angle of the ion beam incident on the wafer, and the incident angle is called the tilt angle.

As shown in FIG. 2, in the prior art, the angle of the rotation axis of the wafer holder (Wafer Chuck) that holds the wafer is adjusted to adjust the inclination angle, which is the incident angle of the ion beam.

However, as shown in Figure 3, the previous tilt angle adjustment method uses High Tilt Angle to implant low-energy ion beams with serious Beam Blow-up phenomenon, and the ion beams reach the upper part of the wafer and the crystal. The distance between the lower part of the circle causes a difference in the ion beam density in the vertical direction of the wafer, which causes the uniformity of ion beam implantation to deteriorate. This is the same as when the flash is turned on at night, the closer the distance is brighter, and the farther the distance is, the more serious the beam divergence and the darkening will be.

In particular, recently, semiconductor devices have become increasingly denser and their circuit widths have sharply decreased. Therefore, in order to make the doping depth thinner and thinner on the wafer surface, it is gradually necessary to use low energy ion implantation.

Therefore, it is necessary to develop an ion implantation device that can perform ion implantation with the same ion beam density even when a low energy ion beam is used at a high tilt angle (Wafer) position.

[Prior Technical Literature]

(Patent Document 1) Republic of Korea Published Patent No. 10-2000-0024763 (Publication date 2000.05.06)

(Patent Document 2) Republic of Korea Published Patent No. 10-2007-0047637 (Publication Date 2007.05.07)

Summary of the invention

The present invention aims to solve the problems of the prior art.

The purpose of the present invention is to provide a semiconductor wafer ion implantation scanning robot, which is installed in a high-vacuum process chamber (Process Chamber) in the field of a terminal station and can scan the wafer in any designated direction in the horizontal direction so that it comes from the terminal (Terminal) The ion beam is uniformly injected into the wafer (Wafer).

Another object of the present invention is to provide a unique scanning method of semiconductor wafer ion implantation scanning robot, even during high-inclination low-energy ion implantation, it can improve the crystal by irradiating the entire area on the wafer with equidistant sub-beams. The doping uniformity on the circle, at the same time, can also meet the doping uniformity requirements of the new generation of semiconductors.

In order to achieve the objective, the semiconductor wafer ion implantation scanning robot of an embodiment of the present invention includes: an L1 axis, which is vertically coupled to one side of the first link, and drives the first link by the driving of the first driving unit Rotation; L2 axis, stack a second link with the same length as the first link on the upper part of the first link, vertically coupled to the other side of the first link and stacked on it On one side of the second link on the second link and driven by the second drive unit to drive the second link to rotate; the R axis, on the other side of the second link, is stacked on top of the support for supporting the scanning head Frame, vertically coupled to the other side of the second link and the center of the support frame and driven by the third drive unit to drive the support frame to rotate; and the Y axis is horizontally coupled to the support frame It supports both sides of the scanning head, and drives the scanning head to rotate by virtue of the driving of the fourth driving unit.

Here, the first drive unit is provided at the lower part of the first link so that the L1 axis is vertically coupled to the first link, and the second drive unit is provided on the other side of the first link. One side inside so that the L2 shaft is vertically coupled to the second link, and the third drive unit is provided in the second The other side of the connecting rod is inside so that the R-axis is vertically coupled to the center of the support frame, and the fourth drive unit is provided on one side of the support frame so that the Y-axis is horizontally coupled to the center of the support frame. The upper end of the support frame.

Moreover, the first drive unit and the second drive unit are driven synchronously, the first link rotates left and right on the basis of the L1 axis, and the second link rotates to the left on the basis of the L2 axis. , Rotate to the right, so that the scanning head moves horizontally to the left and right.

Furthermore, the third drive unit and the first drive unit are driven synchronously, and the R axis drives the scan head to rotate at the same rotation angle as the L1 axis.

In addition, the L1 axis is driven to rotate to adjust the inclination angle, and the driving of the first drive unit and the second drive unit are synchronized under the adjusted inclination angle, and the first link is moved toward the L1 axis as a reference. Rotate left and right, and rotate the second link to the left and right based on the L2 axis, so that the scanning head moves horizontally to the left and right.

Moreover, the third driving unit is driven in synchronization with the first driving unit under the adjusted inclination angle, and the R axis drives the scanning head to rotate at the same rotation angle as the L1 axis.

The Y axis drives the wafer of the scan head to rotate to a wafer loading or unloading position or drives the wafer of the scan head to rotate to an ion implantation position or a beam profiling position.

Moreover, the scan head includes a wafer holder for fixing the wafer, an S-axis for driving the wafer holder to rotate, and a fifth drive unit for driving the S-axis, the S-axis is perpendicular to the Y-axis, The wafer holder on which the wafer is placed is driven to rotate to adjust the twist angle (Twist Angle) or the orientation angle (Orientation Angle) of the wafer.

According to the embodiment of the present invention, the scalar motion that can be scanned in any designated direction in the horizontal direction is realized through the actions of the L1 axis and the L2 axis, and the adjustment is made through the action of the R axis to keep the ion beam constant during the left and right scans. The incident angle of, through the action of the S-axis, can prevent the beam channel effect and prevent the shadow phenomenon according to the crystal direction of the wafer, thereby improving the uniformity of ion beam implantation on the wafer.

Moreover, the entire area on the wafer can be equidistant during high-inclination and low-energy ion implantation. The ion beam irradiation greatly improves the doping uniformity on the wafer, and at the same time, it can also meet the doping uniformity requirements of the new generation of semiconductors.

10: Air bearing

100: first link

110: The first drive unit

120: L1 axis

200: second link

210: second drive unit

220: L2 axis

300: support frame

310: Third drive unit

320: R axis

400: Scan head

401: Wafer holder

402: S axis

403: Fifth drive unit

410: The fourth drive unit

420: Y axis

L1, L2, R, Y: axis

FIG. 1 is a conceptual diagram showing a conventional wafer beam scanning method.

FIG. 2 is a conceptual diagram showing the tilt angle adjustment operation in the conventional wafer beam scanning method shown in FIG. 1. FIG.

FIG. 3 is a side view for explaining the problem of large-angle oblique ion implantation of the wafer in the conventional wafer beam scanning method shown in FIG. 1 and FIG. 2.

4 is a conceptual diagram showing a wafer beam scanning method of a semiconductor wafer ion implantation scanning robot according to an embodiment of the present invention.

5 is a simulation diagram illustrating the structure of a semiconductor wafer ion implantation scanning robot according to an embodiment of the present invention.

Fig. 6 (a) and (b) illustrate the operation of the L1 axis, L2 axis, and R axis of the semiconductor wafer ion implantation scanning robot according to an embodiment of the present invention. The driving units of the L1 axis, L2 axis, and R axis are driven in synchronization to perform left and right scanning operations. Figure.

(A) and (b) of FIG. 7 illustrate a semiconductor wafer ion implantation scanning robot 45 according to an embodiment of the present invention. Action diagram of tilt scan action.

(A) and (b) of FIG. 8 are operation diagrams explaining the operation of the scan head based on the Y-axis drive in the semiconductor wafer ion implantation scanning robot according to an embodiment of the present invention.

Figure 9 (a) and (b) illustrate the adjustment of wafer twist angle (Twist Angle) or azimuth angle (Orientation Angle) adjustment by means of the S-axis drive of the scan head in the semiconductor wafer ion implantation scanning robot according to an embodiment of the present invention Action figure.

FIG. 10 is a top view illustrating the uniformity of doping when the semiconductor wafer ion implantation scanning robot performs large-angle and inclined ion implantation of the wafer according to an embodiment of the present invention.

Detailed description of the preferred embodiment

The following detailed description of the present invention is an embodiment of the present invention that can be implemented, and reference is made to the drawings as an example of the embodiment in the description. In order to enable those skilled in the art of the present invention to implement the present invention, these embodiments will be described in great detail below. Although the various embodiments of the present invention are different from each other, they should be construed as not necessarily mutually exclusive. For example, the specific shape, structure, and characteristics of an embodiment described can be implemented in another embodiment without departing from the spirit and scope of the present invention. Moreover, the individual positions or configurations in the disclosed embodiments should be construed as being able to be modified without departing from the spirit and scope of the present invention.

Therefore, the following detailed description should not be regarded as restrictive. As long as it can be properly described, the scope of the present invention can only be given by all equivalent ranges equivalent to the requested content of its patent application and the attached patent application scope. limited. Similar symbols in the drawings indicate that their functions are the same or similar in all respects.

The terminology used in the present invention has considered its functions in the present invention and has chosen general terms that are currently widely used as far as possible, but may vary according to factors such as the intention or practice of those skilled in the art or the emergence of new technologies. Changed. Moreover, in certain circumstances, the term arbitrarily selected by the applicant is also used, and its meaning will be described in detail in the corresponding invention content. Therefore, the terms used in the present invention cannot be defined solely by the term name, but should be defined according to the meaning of the term and the overall content of the present invention.

Throughout this specification, when it is said that a certain part "includes" a certain component, it means that, unless the contrary content is specifically stated, it does not exclude other components but can also include other components.

Moreover, terms such as "...unit" and "...module" described in the specification refer to a unit that processes at least one function or action, which can be implemented by hardware or software, or through a combination of hardware and software. achieve.

As shown in Figure 4 and Figure 5, for vertical ribbon beam (Vertical Ribbon Beam) or vertical Vertical scanning ion beam (Vertical Scanning), the semiconductor wafer ion implantation scanning robot of an embodiment of the present invention transmits the action of the 5 drive shafts consisting of L1 axis, L2 axis, R axis, Y axis, and S axis to the movement in the horizontal plane. Left and right mechanical scanning in all directions.

First, as shown in FIG. 5, a first drive unit 110 is provided at the lower part of one side of the first link 100. The L1 shaft 120, which is the drive shaft of the first drive unit 110, is vertically combined with one of the first link 100. side. The L1 axis 120 becomes the reference axis of the scanning robot, and the first link 100 is driven to rotate left and right by the driving of the first driving unit 110.

Furthermore, a second link 200 whose length is the same as that of the first link 100 is stacked on the upper part of the first link 100.

A second drive unit 210 is provided inside the other side of the first link 100, and an L2 shaft 220, which is a drive shaft of the second drive unit, protrudes from the upper part and is vertically coupled to one side of the second link 200. The L2 shaft 220 drives the second link 200 to rotate left and right by the driving of the second driving unit 210.

Moreover, a supporting frame 300 supporting the scanning head 400 is stacked on the upper part of the other side of the second link 200.

A third driving unit 310 is provided inside the other side of the second link 200, and an R shaft 320 as a driving shaft of the third driving unit 310 protrudes from the upper part and is vertically combined in the center of the support frame 300. The R shaft 320 drives the support frame 300 to rotate left and right by the driving of the third driving unit 310.

Here, the first driving unit 110, the second driving unit 210, and the third driving unit 310 are driven after being synchronized.

As shown in Figure 6 (a) and (b), if it is a 0° scan, in the initial state of Figure 6 (a), as shown in Figure 6 (b), the first link 100 is in the first drive unit When the 110 is driven, it rotates based on the L1 shaft 120, and the second link 200, which has the same length as the first link, rotates on the L2 shaft 220 when the second drive unit 210 synchronized with the first drive unit drives. The scanning head 400 is driven to move horizontally to the left and right.

6(b) is further explained in detail below, the first connecting rod 100 due to the first drive unit The drive of 110 rotates to the left on the basis of the L1 axis 120. At the same time, the second link 200 rotates to the left on the basis of the L2 axis 220 due to the driving of the second drive unit 210 synchronized with the first drive unit. , The first link 100 rotates to the right based on the L1 axis 120 due to the drive of the first drive unit 110, and at the same time, the second link 200 is driven by the second drive unit 210 synchronized with the first drive unit. Rotate to the right with the L2 axis 220 as a reference, so that the scanning head 400 moves horizontally to the left and right. At the same time, the scanning head 400 rotates to the left and right with the R axis 320 as a reference due to the driving of the third driving unit 310 synchronized with the first driving unit 110. At this time, the R-axis 320 performs an adjustment function during the left and right scanning process so that the ion beam maintains a certain incident angle.

That is, the scanning head 400 realizes a scalar movement capable of scanning in any designated direction of the horizontal direction by rotating the L1 axis 120, the L2 axis 220, and the R axis 320 at the same time.

Furthermore, as shown in (a) and (b) of Fig. 7, in the case of 45° oblique scanning, as shown in Fig. 7(a), the reference L1 axis 120 is rotated by 45° in the initial state of 0°. At this time, if the L1 shaft 120 is rotated by 45° by the driving of the first driving unit 110, the first link 100, the second link 200, and the scanning head 400 are rotated by an angle of 45°. Furthermore, the scanning head 400 is moved horizontally to the left and right as shown in FIG. 7(b) in a state where the scanning head 400 is inclined at 45°. Here, the left and right horizontal movement of the scan head 400 is realized in the same manner as described in FIG. 6(b).

That is, the scanning head 400 realizes a scalar movement capable of scanning in any designated direction in the horizontal direction when it is inclined at 45°.

On the other hand, the scan head 400 supported by the supporting frame 300 is joined to the horizontally coupled Y-axis 420.

As shown in FIG. 5, a fourth drive unit 410 is provided on one side of the support frame 300, and the Y axis 420 as the drive shaft of the fourth drive unit 410 is horizontally coupled to the support frame 300 and supports both sides of the scan head 400. The driving of the fourth driving unit 410 drives the scan head 400 to rotate.

As shown in (a) and (b) of FIG. 8, the Y-axis 420, which is rotated by the driving of the fourth drive unit 410, plays a role in driving the scanning head 400 to rotate to the wafer loading or unloading position or driving the crystal placed in the scanning head. The function of rotating the wafer of the circular holder to the ion implantation position or the beam profiling position.

As shown in (a) of FIG. 9, the scanning head 400 includes a wafer holder 401 for fixing a wafer, an S-axis 402 for driving the wafer holder 401 to rotate, and a fifth driving unit 403 for driving the S-axis 402.

Moreover, as shown in Figure 9(b), the S-axis 402 is perpendicular to the Y-axis 420, and the fifth drive unit 403 drives the wafer holder 401 on which the wafer is placed to rotate to adjust the wafer ( Wafer's twist angle (Twist Angle) or azimuth angle (Orientation Angle).

Here, the first reason why Tilt Angle and Twist Angle need to be adjusted during ion implantation is to prevent the beam channeling effect caused by the crystal orientation of the semiconductor and the beam incident angle needs to be adjusted to The second reason for the difficult crystal orientation of the channel effect is that to prevent the shadow phenomenon that occurs in the recent oblique ion implantation of semiconductors with three-dimensional structures, ion implantation needs to be performed at various angles.

Therefore, the present invention realizes scalar motion that can scan in any specified direction in the horizontal direction through the actions of the L1 axis 120 and the L2 axis 220, and adjusts through the action of the R axis 320 to keep the ion beam constant during the left and right scanning process. Through the S-axis 402, the incident angle can prevent the beam channel effect and prevent the shadow phenomenon according to the crystal direction of the wafer, thereby improving the uniformity of ion beam implantation on the wafer.

FIG. 10 is a top view illustrating the uniformity of doping when the semiconductor wafer ion implantation scanning robot according to an embodiment of the present invention performs large-angle and inclined ion implantation of the wafer.

As shown in FIG. 10, the semiconductor wafer ion implantation scanning robot scans the wafer with uniform ion beam density at all positions on the wafer during 0° Tilt Implantation (0° Tilt Implantation).

At the same time, even if tilted at a large angle, the vertical ribbon ion beam or the vertical scanning ion beam will be scanned from left to right on the wafer, so there is no difference in the beam path regardless of the tilt angle. Therefore, wafer scanning During the process, the beam uniformity is maintained constant so that ions can be implanted uniformly at all positions on the wafer.

As mentioned above, the present invention can scan the wafer in any designated direction in the horizontal direction so that the ion beam can be uniformly implanted on the wafer (Wafer), even during high-inclination low-energy ion implantation, it can also make the wafer on the wafer The whole area is irradiated by equidistant sub-beams to greatly improve the uniformity of doping on the wafer.

Moreover, it solves the problem of doping uniformity caused by the distance difference of the ion beam path of each wafer position in the scanning direction in the prior art and the resultant ion beam size change. At the same time, it is also compatible with the new generation of semiconductors. The doping uniformity requires conditions.

The foregoing describes the preferred embodiments of the present invention, but the present invention is not limited to the specific embodiments. That is, those with general knowledge in the technical field to which the present invention belongs can make various changes and modifications to the present invention without departing from the spirit and scope of the claims. All these appropriate changes and modifications shall be construed as equivalents as belonging to this invention. The scope of the invention.

L1, L2, R, Y: axis

Claims (8)

A semiconductor wafer ion implantation scanning robot, which includes: an L1 axis, which is vertically coupled to one side of a first link, and drives the first link to rotate by the driving of the first driving unit; and the L2 axis is in the The upper part of the first link is stacked with a second link whose length is the same as that of the first link, and the second link is vertically combined on the other side of the first link and the second link stacked on it The second link is driven by the second drive unit to rotate the second link; the R-axis is stacked on the upper part of the other side of the second link to support the support frame for the scanning head, which is vertically connected to the The other side of the second link is connected to the center of the support frame and is driven by the third drive unit to drive the support frame to rotate; and the Y axis is horizontally coupled to the support frame and supports the two scanning heads. Side, driven by the fourth drive unit to drive the scan head to rotate; wherein the L1 axis is driven to rotate to adjust the tilt angle, and the drive of the first drive unit and the second drive unit are synchronized under the adjusted tilt angle. Use the L1 axis as a reference to rotate the first link to the left and right, and use the L2 axis as a reference to rotate the second link to the left and right, so that the scanning head moves to the left and right Move horizontally. The semiconductor wafer ion implantation scanning robot according to claim 1, wherein the first driving unit is provided at a lower part of the first link so that the L1 axis is vertically coupled to the first link, and the Two driving units are provided inside the other side of the first link so that the L2 shaft is vertically coupled to the second link, and the third drive unit is provided on the other side of the second link Side inside so that the R axis is vertically coupled to the center of the support frame, and the fourth drive unit is provided on one side of the support frame so that the Y axis is horizontally coupled to the upper end of the support frame . The semiconductor wafer ion implantation scanning robot according to claim 1, wherein the first driving unit and the second driving unit are driven synchronously, and the first link rotates to the left and right on the basis of the L1 axis, so The second link rotates left and right based on the L2 axis, so that the scanning head moves horizontally to the left and right. The semiconductor wafer ion implantation scanning robot according to claim 3, wherein the third driving unit and the first driving unit are driven synchronously, and the R axis drives the scanning at the same rotation angle as the L1 axis The head rotates. The semiconductor wafer ion implantation scanning robot according to claim 1, wherein the third driving unit is synchronously driven with the first driving unit under the adjusted inclination angle, and the R axis is the same as the L1 axis The angle of rotation drives the scan head to rotate. The semiconductor wafer ion implantation scanning robot according to claim 1, wherein the Y axis drives the wafer of the scan head to rotate to a wafer loading or unloading position or drives the wafer of the scan head to rotate to an ion implantation position Or beam profile analysis position. The semiconductor wafer ion implantation scanning robot according to claim 1, wherein the scanning head includes a wafer holder for fixing a wafer, an S-axis for driving the wafer holder to rotate, and a fifth for driving the S-axis. Drive unit. The semiconductor wafer ion implantation scanning robot according to claim 7, wherein the S axis is perpendicular to the Y axis, and the wafer holder on which the wafer is placed is driven to rotate to adjust the twist angle of the wafer (Twist Angle ) Or Orientation Angle.

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