JPS6167914A - Linear energy beam irradiating device - Google Patents

Abstract

PURPOSE:To perform a uniform beam irradiating process on the large diameter material to be processed maintaining the dynamic balance of a rotating stand by a method wherein a pair of X-Y shifting mechanisms are provided symmetrically against the rotating shaft of the rotary stand, and a linear beam is made to irradiate on the material to be processed by moving the X-Y shifting mechanism symmetrically against the rotating shaft. CONSTITUTION:Clutches CL1-CL4 are coupled to the movable screws 36, 37, 46 and 47 on a pair of X-Y stages 33 and 34 which are symmetrically provided on the rotating shaft 3 located on a rotary stand 2, the X-Y stages 33 and 34 are shifted symmetrically against the rotating shaft by motors 51, 52, 61 and 62, and the center of wafers 11-14 is positioned directly below the four windows 22 of a beam mask 21. The clutches CL1-CL4 are separated with each other, a turn table 2 is rotated at a constant speed, a linear beam is made to irradiate while the source of beam is being pivotally moved in such a manner that the longitudinal direction of the linear electron beam is brought in the state wherein it is in parallel with the straight line which passes the center of both wafer 1 and the turn table 2. When an irradiation is finished, the movement of the turn table 2 is stopped, the X-Y stages 33 and 34 are shifted, and the next irradiation is performed. A uniform irradiation process is performed by repeating the above-mentioned procedures.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to a linear energy system suitable for application to, for example, an apparatus for recrystallizing a polycrystalline silicon film on an insulating substrate to form a single-crystal silicon film. The present invention relates to a device that irradiates a target object with a beam.

[Conventional technology]

In response to demands for higher density and higher performance for silicon semiconductor devices represented by LSI, so-called 5OI (Silicon'
On In5ula'tor) technology has been developed.

This method involves depositing a polycrystalline silicon film on a quartz substrate or a silicon crystal substrate (uniha) on which an oxide film is formed as an insulating layer. It melts locally for a short period of time and recrystallizes by cooling it to form a silicon single crystal film.

First, with reference to FIGS. 8 to 10, an example of the configuration of a conventional linear energy beam irradiation device for recrystallizing polycrystalline silicon on an insulating substrate to form a single crystal silicon film. I will explain about it. In FIGS. 8 and 9, (2) is a turntable, and a plurality of wafers (1) coated with a polycrystalline silicon film are placed on this turntable (21) through a plurality of appropriately arranged openings. (2a
) is placed so as to cover it. The turntable (2) is rotated by a motor (7g) via a rotating shaft (3). (6) is an electron beam source that generates a linear electron beam (5), which is successively opposed to each wafer (1). a control power source (7) arranged to control the beam source (6);
A rotational position information signal is supplied from an encoder (8) directly connected to the motor (4). A known rotation control circuit (9) is connected between the encoder (8) and the motor (4).

Wafer (1), turntable (2) and beam source (
6) is housed as a whole in vacuum container a [, and vacuum container a
A suitable number of windows (11) made of quartz glass are provided in the shim to face each opening (2a) of the turntable (2),
An infrared lamp (12) for preheating the wafer (1) is arranged outside the window (11). Vacuum vessel α [exhaust pipe (
13) is connected to a vacuum pump (not shown).

Note that the infrared lamp (12) is arranged so as not to face the electron beam source (6).

The operation of a conventional linear beam irradiation device is as follows.

The wafer (1) is placed on the opening (2a) of the turntable (2).
) is preheated by an infrared lamp (12) through a window (11). When the wafer (1) reaches a predetermined temperature, the infrared lamp (12) is turned off and the turntable (2) is driven by the motor (4) to a temperature of, for example, 500-1100.
Rotates at about 0 rpm. When the turntable (2) reaches a predetermined speed, the control power source (7) is timed by the rotational position information signal supplied from the encoder (8), and the turntable (2) moves as shown in Figure 1O. angle 2
An electron beam (5) is emitted from a linear electron beam source (6) during a period of rotation by θ. Thus, as shown in FIG.
, (lr) is represented by (5a
), (5b).

The polycrystalline silicon film is melted by being scanned by the irradiation rays of the electron beam (5) represented by (5c).
Recrystallization is performed by subsequent cooling, and a single crystal silicon film is formed.

[Problem that the invention seeks to solve]

However, in such conventional linear beam irradiation equipment, the size of the wafer (1) that can be processed is limited by the length of the beam (5), and it is difficult to process large diameter wafers. The drawback was that I couldn't do it.

In order to solve this problem, it is possible to move the wafer, but if you try to move the wafer to the car, the dynamic balance will be disrupted and the turntable (2) will be moved.
A problem arises in that the rotation is not smooth.

[Means for solving problems]

The present invention includes a rotary table (2) on which the object to be processed (1) is placed, and a linear energy beam source (6) arranged in the radial direction of the rotary table (2), The linear energy beam from this linear energy beam source (6) is applied to the object to be processed (1).
In a linear energy beam irradiation device that irradiates 1,
At least one pair of XY movement mechanisms (30
), (40) are arranged symmetrically to the rotation axis (3) of the rotary table (2), and the XY movement mechanism (30), (
40) are moved symmetrically with respect to the rotation axis (3).

[Effect]

According to the present invention, the object to be processed (11) is irradiated with the linear energy beam through the irradiation area regulating means (21) while rotating the turntable (2), and then the turntable (2) is stopped and the xy The moving mechanisms (30) and (40) are moved a predetermined distance in the X direction and the Y direction symmetrically with respect to the rotation axis (3) of the lrl turntable (2).Hereinafter, the rotation of the turntable (2) and the irradiation area regulating means (21) Irradiation of the linear energy beam and movement of the irradiation area moving mechanism are repeated, and the object to be processed (
1) The entire surface of the area is irradiated with a linear energy beam.

〔Example〕

Hereinafter, one embodiment of the linear energy beam irradiation device according to the present invention will be described with reference to FIGS. 1 to 4. In FIGS. 1 and 2, parts corresponding to those in FIGS. 8 and 9 are designated by the same reference numerals, and redundant explanation will be omitted.

In FIGS. 1 and 2, (21) is a beam mask tear made of a high melting point metal such as molybdenum, and is fixed to the rotating shaft (3) of the turntable (2). The beam mask (21) has a plurality (41 rounds in the figure) of square windows (22) with a side length of E arranged at predetermined angular intervals, and the linear electrons passing through the windows (22) By the beam (5), a plurality of (four in the figure) wafers 11) ((11) to (14)
) A predetermined area of ) is irradiated.

(30) and (40) respectively show a pair of XY moving mechanisms as irradiation area moving means as a whole.

Since both XY movement mechanisms (30) and (40) have the same configuration, the reference numeral of each corresponding component will have the same first digit, and one movement ivJ mechanism (30) will be explained.
Description of the other moving mechanism (40) will be omitted.

(31) and (32) are wafer holding tables, (33) is
The Y stage, (33u) and (331) are its upper block and bottom block. Both wafer holding stands (
31), (32) are connected to the upper block (33u) by arms (34) and (35). (36) and (37) are screws for movement in the X direction and movement in the Y direction, respectively, and are screws for the upper block (33u
) and the lower block (33β).

The tip (38) of the X movement screw (36) via the axial direction conversion mechanism (36c) and the tip (39) of the Y movement screw (37)
The driving force is transmitted to as described below. move ull
Structure (30) wafer (
11 (can move by a distance approximately equal to 1 yen in D straight).

The self-moving mechanisms (30) and (40) are connected to the turntable (2
) is disposed symmetrically with respect to the rotation axis (3), and
Corresponds to each. F Do Block (33u),
(43u), (33N), (437) are moved symmetrically with respect to the rotation axis (3), so that the dynamic balance of the turntable (2) is maintained regardless of this movement. Further, in order to make the rotation of the turntable (2) more round, a pair of balancers (2b) are arranged on the turntable (2) symmetrically about the rotation axis (3).

(51) and (52) are motors for moving in the X direction and in the Y direction for one of the moving mechanisms (30), and drive shafts (53) and (54) of the motors (51) and (52).
) are the airtight bearings (15) and (16) of the vacuum container (14).
The four ends (55) and (56) of the drive shafts (53) and (54) are respectively supported by the X movement screw (36) and Y movement screw (37) of the movement mechanism (30). Latch CL that can be engaged with and separated from the tips (38) and (39)
1 and Cl3. A light source (laser diode) for a position sensor (not shown) facing the XY stage (33) is provided on the upper block (33u).Similarly, (61) and (62) are A motor for moving in the X direction and in the Y direction for the moving mechanism (40), in which the drive shafts (63) and (64) of the motors (61) and (62) are fitted with airtight bearings (17) and (18).
) is slidably supported on the drive shafts (63) and (64).
The four ends (65) and (66) of the latch C can be engaged with and separated from the tips (48) and (49) of the X movement screw (46) and Y movement screw (47) of the movement mechanism (40), respectively.
Configure L3 and Cl3.

In addition, the upper block (43u) of the XY stage (43)
A light source (67) for a position sensor is provided.

(71) is a motor that drives the electron beam source (6), and its drive shaft (72) passes through the vacuum vessel (ll) and is coupled to the electron beam source (6). An encoder (73) is directly connected. (74) is a comparison circuit, to which a reference rotational position information signal of the turntable (2) is supplied from the encoder (8), and an electron beam source ( The rotational position information signal of 6) is supplied.The output of the comparator circuit (74) is supplied to the drive amplifier (74).
75) to the motor (71).

The operation of this embodiment is as follows.

First, the electron beam is applied to four wafers (IL) ~ (14)
4, so as to irradiate the same position, for example, the center of each
movement motors (51), (52).

(61) and (62) as clutch CL1. CL...
CL3゜XY stage (33) via Cl3,
(43) moving screws (36), (37),
(46), (47), and four wafers (
The center of each of (11) to (14) is a beam mask (2).
The father Y stages (33) and (43) are driven so that they are located directly in front of the four windows (22) in 1). Clutches CLI-CL4 are disengaged, and the turntable (2) is rotated after the wafer (1) is preheated by an infrared lamp (not shown) as in the conventional case. The turntable (2) reaches a constant speed rotation state under the control of the rotation control circuit (9), and the linear electron beam (5) is emitted from the electron beam source (6).
), the 1-day wafer (11) is at the position marked by the circle (1a) in Figure 3'.
At this time, the longitudinal direction (83a) of the linear electron beam source (6) is located at the center (81a) of the wafer (1a).
) and the center (2c) of the turntable (2).

During the emission period of the linear electron beam, the turntable (2) rotates counterclockwise by an angle of 2θ, so that the wafer (11) passes through the position where it is marked by the circle (1b), and then moves to the circle (IC).
) to the position shown. During this period, the motor (
71), the electron beam source (6) rotates counterclockwise around its rotation center C6 at the same speed as the turntable (2), and in FIG.
It moves through the position shown in b) to the position shown in area (6c). The longitudinal direction (83c) of the region (6c) is between the center (81c) of the wafer (1c) and the turntable (
It becomes parallel to the straight line (82c) connecting the center (2C) of 2).

As mentioned above, the 'C11 beam 141 (6) ((6a) to (6c) rotating in synchronization with the turntable (2)
) Irradiation rays (5d) by a linear electron beam (5) emitted from l.

(5a) and (5f) are parallel to the 111 diameter of the turntable (2) passing through the center of the wafer (ttll) as shown in Figure 4, so the irradiation density on the wafer (1) is uniform. become.

If there is no beam mask (21), the irradiation area of the electron beam is the construction of the irradiation lines (5d) to (5'') every moment, and the upper edge (84) and lower edge ( 85) both have a radius of curvature equal to the distance 1%tiR between the center (2c) of the turntable (2) and the rotation center CG of the electron beam source (6).

However, the irradiation regulation area in which the irradiation area is regulated by the beam mask (21) is equal to the projection (22p) of the window (22) of the mask (21) onto the wafer (11). The uneven intensity portions at both ends of the linear beam (5) in the longitudinal direction are removed, and the irradiation energy density within the irradiation regulation area becomes uniform.

Even after the irradiation of the center of the wafer (11) on the first day is finished,
The turntable (2) continues to rotate at a constant speed, and the second-day wafer (12) is placed in the window (22) of the beam mask (21).
) and approaches below the electron beam source (6). At this time, the electron beam source (6) is in the area (6a) in FIG.
), so in this example, the drive motor (71) of the electron beam source (6)
For example, a step motor with excellent start-up characteristics is used, and the electron beam source (6) is rotated clockwise during the electron beam pause period.

In addition, in order to perform the required constant speed rotation even in such reciprocating rotation, there is a rising period before and after the required constant speed period,
It is preferable to provide a falling period number. In this case, the total rotation angle will naturally be larger than the required rotation angle, and if the angular spacing of the wafer is narrow, the electron beam source (6) will move from the beam firing end position to the beam firing starting position within the time corresponding to this angular spacing. You will not be able to return until In such a case, after the irradiation treatment of the wafer (11) on the 1st day, the turntable (2) should be
During the rotation, the electron beam source (6) is returned to the beam emission starting position, and the second wafer (12) is irradiated.

When the first electron beam irradiation on each wafer (11) to (14) is completed, the rotation of the turntable (2) is stopped, each clutch CLI-CL4 is engaged again, and the moving mechanisms (30) and (40) are ) in the X or Y direction in a symmetrical manner with respect to the rotation axis (3) of the turntable (2). In order to make the second beam irradiation regulation area adjacent to the first beam irradiation control area, the movement distance is set equal to the length l of one side of the square window (22) of the beam mask (21). The following describes the separation of clutches CLI to CL4 and the turntable (2
), the entire surface of the wafer can be uniformly processed by repeating the rotation of the wafer, electron beam irradiation, stopping the turntable, and moving the wafer.

Next, other embodiments of the present invention will be described with reference to FIGS. 5 and 6.

In FIG. 5, (110) and (120) are irradiation area moving means, and each of the pair of XY moving mechanisms is shown as a whole.

One moving mechanism (110) includes an X stage (111),
It is equipped with a Y stage (112) that also serves as a wafer holding table, and a moving screw (113) that is screwed into the X stage (111).
A pulley (114) is provided at one end of the Y stage (112), and a moving screw (115) that becomes part of the transmission shaft (105) (7) is screwed into the Y stage (112). The other moving mechanism (
120) is also constructed in the same way as the above-mentioned moving mechanism (110), so the reference numerals of the corresponding components have the same first digit and the explanation will be omitted, but the moving screw (120)
3) The engraving direction of the screws (113) and (125) is opposite to that of the corresponding movement screws (113) and (115).

The recalibration mechanisms (110) and (120) are arranged symmetrically on the turntable (2) with respect to its center of rotation.

The tip (102) of the transmission shaft (101) forms a latch CL5 that engages and separates from the four ends (55) of the drive shaft (53) of the X-direction moving motor (5). A pulley (104) is provided at the other end of the shaft (101), and this boo'J (
belt (104) and the pulleys (114) and (124) of the above-mentioned moving mechanisms (110) and (120).
03) is suspended. In addition, as shown in FIG. 6, this bell 1-(103) is equipped with a tension roller (107).
, (108) provides the required tension. The tip (106) of the transmission shaft (105) engages with the four ends (56) of the drive shaft (54) of the motor (52) for moving in the Y direction.
The latch CL6 is configured with the function 1II6J.

In this embodiment, ζ is a beam mask (not shown) in which a pair of rectangular windows (22R) are provided at predetermined positions so that the long sides thereof are perpendicular to the radial direction of the turntable (2). . In addition, on the same side of the turntable (2) as the electron beam source (not shown), there is a pair of infrared lamps (one
(not shown) are arranged at an angular spacing of 90° from the electron beam source. Therefore, the beam mask only needs to cover the vicinity of the window (22R) through which the electron beam passes. Note that an appropriately shaped arm can be fixed to one Y stage (122), and a position detection light source common to both XY moving mechanisms (110) and (120) can be provided there.

The operation of this embodiment is as follows.

First, the electron beam hits two wafers (11).

The two moving motors (51) and (52) are connected to the CL5. XY movement mechanism (1
10), (120) displacement screw (113).

(115), (123), (125), and the centers of the two wafers <lx) and (h) are directly connected to the two windows (22R) of the beam mask (21), respectively).
Position 1 - Ruyouni, XY movement a structure (110),
(120). Clutches CL5 and Cl3 are disengaged, the wafer (1) is preheated by an infrared lamp (not shown), and then the turntable (
2) Rotate. When the turntable (2) reaches a constant speed rotation state under the control of the rotation control circuit (9) and the first plate (1) approaches the bottom of the electron beam source (6). , similar to the previous embodiment, the electron beam source (6) rotates in synchronization with the turntable (2) at a constant speed and in the same direction;
The irradiation line of the electron beam on the wafer (11) is parallel to the radius vector of the turntable (2) passing through the center of the wafer.

After the irradiation of the central part of the first wafer (11), two wafers placed at an angular interval of 180° on the turntable (2)
When the first wafer (12) comes under the electron beam source (6), the electron beam source (6) is in the same positional relationship as it was with the first wafer (11). In other words, the electron beam source (6) must also rotate by the same angle as the turntable (2). Since the linear beam has no directionality in its longitudinal direction, in the case of this embodiment, the electron beam source (6) does not need to rotate back and forth as in the previous embodiment, and can be rotated continuously. , its rotation control becomes extremely easy. In this case, the electron beam source (6) is supplied with power via a slip ring.

In addition, a microcomputer can also be used to control the rotation of the motor (71), including the above-mentioned embodiments.

When the first electron beam irradiation on the meat wafers (11) and (12) is completed, the rotation of the turntable (2) is stopped, and the clutches CL5 and Cl3 are engaged.
The iJJ mechanisms (110) and (120) are moved in the X direction or the Y direction symmetrically with respect to the rotation axis (3) of the turntable (2). In order to make the second beam irradiation regulation area adjacent to the first one, the moving distance is determined by the beam mask (21
) are set equal to the lengths l and w of the long and short sides of the rectangular window (22R). Below, clutch CL5. By repeating separation of the CL6, rotation of the turntable (2), electron beam irradiation, stoppage of the turntable, and movement of the wafer, the entire surface of the wafer can be uniformly processed.

When the self-moving mechanisms (110) and (120) move in the Y direction, the distance between the pulleys (114) and (124) connected to the X moving screws (113) and (123) changes, but as shown in FIG. Pulley (114) as shown.

(124) The tension roller (
107) and (108) are displaced, and the belt (103
) remains constant.

Incidentally, the radius of curvature of the upper and lower edges of the wide arc-shaped irradiation area on the wafer to be processed is equal to the distance MR between the respective rotation centers of the turntable and the electron beam source, as described above. When the rotation angle 2θ of the turntable and the beam source during one period of one beam irradiation is constant, the arc length of the irradiation area becomes longer when the rotation center distance σ month/HMIIR is larger, and the irradiation area becomes larger. -, the number of irradiations per wafer can be reduced.

This situation is shown in FIG. In FIG. 7, CGO is the center of rotation of the electron beam source (6). Since the other parts correspond to those in FIG. 3, they are given the same reference numerals and redundant explanation will be omitted.

As shown in FIG.
(Cic)), for example, move the motor (71) in Fig. 2 in the radial direction of the turntable (2), fix the center of the arm member to the rotation axis (72),
A pair of linear electron beam sources may be attached to both ends of the arm member so that the elongated directions of the beams are on the same straight line, and the arm member may be continuously rotated in synchronization with the turntable (2).

Note that as the distance between the rotation centers of the turntable and the electron beam source increases, the shape of the irradiation area on the wafer becomes closer to a rectangle, and the portion shielded by the beam mask can be reduced.

Although the present invention has been described above in the case where it is applied to silicon wafer processing using an electron beam, the present invention is not limited to the above embodiments, and linear beams such as laser light, X-rays, heat rays, ion beams, etc., and the object to be processed can be applied to not only semiconductors but also insulators and metals.

〔effect〕

As described in detail above, according to the present invention, at least one pair of xy moving mechanisms are disposed symmetrically about the rotating axis of the rotating table, and each of the XY moving mechanisms is moved symmetrically about the rotating axis of the rotating table. This makes it possible to irradiate a large-diameter object with a linear energy beam, and at the same time, the dynamic balance of the rotary table is maintained, smooth rotation is maintained, and beam irradiation becomes uniform.

Brief Explanation of the Drawings FIGS. 1 and 2 are a plan view and a block diagram showing an embodiment of the linear energy beam irradiation device according to the present invention, and FIG.
4 and 4 are route maps for explaining the present invention, FIGS. 5 and 6 are plan views and side views showing other embodiments of the present invention, and FIG. 7 is for explaining the present invention. FIGS. 8 and 9 are a plan view and a block diagram showing an example of a conventional linear energy beam irradiation device, and FIG. 1O is a route map for explaining the conventional device.

(2) is a turntable, (6) is a linear energy beam source, (21) is a beam mask, (30), (4
0).

(110) and (120) are XY movement mechanisms, (51
).

(52), (61), and (62) are moving motors, and (71) is a beam source rotation motor.

Claims (1)

[Claims] It has a rotary table on which the object to be processed is placed, and a linear energy beam source arranged in the radial direction of the rotary table, and the linear energy beam from the linear energy beam source is applied to the object to be processed. In the linear energy beam irradiation device for irradiating the area, at least one pair of XY moving mechanisms are disposed on the rotary table symmetrically with respect to the rotation axis of the rotary table, and the XY
A linear energy beam irradiation device characterized in that each of the moving mechanisms is moved symmetrically with respect to the rotation axis.