JPS6180815A - Linear energy beam irradiation equipment - Google Patents

Abstract

PURPOSE:To enable connecting a limited irradiation region due to each square aperture on a matter to be treated by appropriately rotating plural square apertures provided spirally moving a beam source to the radial direction of a turn table rotating a linear energy beam source the equal angle with the rotation angle of the turn table on which the matter to be treated is placed. CONSTITUTION:Irradiation ray turning means 71 which turn the irradiation rays due to a linear energy beam on a matter to be treated the equal angle with the rotation angle of a turn table 2 at the center of one point on the radial direction of the turn table 2 in accordance with the rotation of the turn table 2, beam source moving means 90 which move a linear energy beam source 6, to the radial direction of the turn table 2 and irradiation limiting means 20 provided with plural square apertures 21a-21d spirally are provided and a linear energy beam irradiation region encircled with a pair of arcs and a pair of parallel lines formed by irradiation rays is limited by the irradiation region limiting means 20. By appropriately rotating the irradiation region limiting means 20, a limited irradiation region due to each square aperture 21a-21d is connected on the matter 1 to be treated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention provides a linear method suitable for use in, for example, an apparatus ξ for recrystallizing polycrystalline silicon crotches on an insulating substrate to form single crystal silicon crotches. The present invention relates to a device that irradiates an object to be processed with an energy beam.

[Prior art] Silicon semiconductor devices represented by LSI: 1L for 6
In response to demands for increased Ii density and improved crystal performance, so-called 5Or (Sili
Con on In5ulator) technology has been developed.

This is a right-handed substrate or a silicon crystal substrate.
A layer of polycrystalline silicon is deposited on top of which an oxide film is formed as an insulating layer, and the polycrystalline silicon is melted locally for a short period of time by, for example, irradiation with a linear electron beam.
By cooling it, it is recrystallized to form a silicon single crystal film.

First, with reference to FIGS. 5 to 7, an example of the configuration of a conventional linear energy beam irradiation device for recrystallizing polycrystalline silicon on an insulating substrate to form single crystal silicon IIQ. I will explain about it. Figures 5 and 6
In the figure, (2) is a turntable, and a plurality of wafers (1) coated with polycrystalline silicon IIQ are placed on this turntable (2) through a plurality of appropriately arranged openings (2a). It is placed so that it looks like this. Turntable (2
) is rotated by a heptad (4) via a rotating shaft (3). (6) is an electron beam source that emits a linear electron beam (5), which is arranged so as to face each wafer (1) sequentially, and a control wire (7) that controls the beam Δb (6). has an encoder (8) directly connected to the motor (4).
) is supplied with a rotational position information signal. A known rotation control circuit (9) is connected between the encoder (8) and the motor (4).
) are connected.

Wafer (1), turntable (2) and beam source (
6) is housed in the vacuum container αω as a whole, and the vacuum container a
A suitable number of quartz glass windows (11) are provided opposite each opening (2a) of the turntable (2),
An infrared pair (12) for preheating the wafer (11) is arranged outside the wafer (11).The exhaust pipe (13) of the vacuum container α0 is connected to a vacuum pump (not shown). Note that the infrared pair (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 couple (12) through a window (11). When the wafer (11) reaches a predetermined temperature, the infrared pair (12) is deactivated and the turntable (2) is driven by the motor (4), e.g.
Rotates at about rp. When the turntable (2) reaches a predetermined speed, the control power source (7) is timed and controlled by the rotational position information signal supplied from the encoder (8).
As shown in FIG. 7, an electron beam (5) is emitted from a linear electron beam source (6) while the turntable (2) rotates by an angle of 2θ. Thus, as shown in FIG. 7, (lp), (lq),
The Sol pattern represented by (lr) is (5a)
, (5b).

The polycrystalline silicon I9 is melted by being scanned by the irradiation beam (5), represented by (5c), and then recrystallized by cooling to form a single crystal silicon film. It is formed.

[Problem that the invention seeks to solve]

However, in such a conventional linear beam irradiation device, since the longitudinal direction of the linear beam (5) is in the a+t1 direction of the turntable (2), as shown in FIG. (5a) to (5c) are arranged radially on the wafer (11) and are connected to the rotation axis (3) of the turntable (2).
The irradiation energy density of the electron beam (5) varies depending on the distance from the wafer (1), which has the disadvantage that the entire wafer (1) cannot be uniformly processed. In addition, irradiation rays (5a) to (5c
) is the pattern (1p) on the wafer (1) ~
The alignment direction of (l'') does not necessarily match, and the processing conditions for crystallization are slightly different depending on the location of J and lJ.
It had the disadvantage that the performance was less than 11.

Furthermore, the beam irradiation period is sufficiently long, and the irradiation rays (5a) to (
5C) scans from one end of the wafer tit to the other;
J-Associated C, which can be used with both, also has the disadvantage that the length of the beam (5) limits the size of the wafer (]) that can be processed, making it impossible to process wafers with large diameters. .

In order to overcome this drawback, it is possible to move the wafer in the radial direction of the turntable, but this poses the problem of requiring multiple mechanisms to move the wafer on the turntable. .

Another problem arises in that the number of beam irradiations per wafer stage must be minimized in order to improve processing efficiency.

Means for Solving Problem c] The present invention provides a rotary table (2) on which an object to be processed (11 is placed) and a linear energy heel disposed in the radial direction of the rotary table (2). source (6), and directs the linear energy beam from the linear energy beam dtrtω to the object to be processed (
In the linear energy beam irradiation device 6 that irradiates the object (1) with the linear energy beam, as the rotating table (2) rotates, the linear energy beam irradiation device 6 The irradiation beam rotation means (71) rotates the rotation angle of the rotary table (2) by an amount equal to the rotation angle of the rotary table (2) around a point in the direction, and the linear any-milgy beam source (6) is rotated by the radius of the rotary table (2). A beam control means (90) for moving the beam in the direction, and an irradiation area regulating means (20) in which a plurality of rectangular openings (2b] to (21d) are arranged to form a vortex are provided. The irradiation area of the linear energy beam is surrounded by a pair of circular arcs and a pair of parallel lines;
0).

[Effect]

According to the present invention, the linear energy beam source (6)
The beam source (6 ) corresponding to the movement of the irradiation area regulating means (20)
Each square opening (21a) is opened by rotating the
Irradiation regulation area (2ip) by ~(21d) ~(2
1s) or connected on the destroyed body fil.

〔Example〕

Hereinafter, an 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. 5 and 6 are designated by the same reference numerals, and redundant explanation will be omitted.

In FIGS. 1 and 2, (20) is a beam mask made of a high-melting point metal such as molybdenum, and is disposed above and coaxially with the turntable (2). A carbon sheet or the like is adhered to the side surface. The beam mask (20) has two sets of multiple rectangular windows (
21) ((21a) to (21d)).

(22) ((22a) to (22d)) are arranged at angular intervals of 45° so as to be successively closer to the center of the mask (20) by the width W thereof. This window (21)
, (22) is set so that an integral multiple (4 times in this example) of the width W is equal to or slightly larger than the diameter of the wafer (1), and the linear shape passing through this Two wafers (
1) All songs ((11), (12)) are irradiated so as to be divided into a plurality of regions. Two sets of windows (21).

(22) are arranged symmetrically with respect to the center of the turntable (2), so in the following explanation, both sets of windows <21
), (22), one set of windows (
21) is represented by °C.

(23) is a lifting and lowering mechanism that lifts, lowers and rotates the mask (20), and is a rotary shaft (3) of the turntable (2).
) under 1'7! : i is attached integrally thereto and connected to the beam mask (20) via a connecting culm (24) disposed within the rotating shaft (3). The lifting/lowering rotation mechanism (23) includes a motor (2) for rotating the mask (20) at a required degree.
5), the motor (25) is coupled with the connecting culm (24) by a clutch (26). Further, an encoder (8) is attached to the elevating and rotating mechanism (23).

A gear (31) is attached to the lower part of the rotation φd+ (31), and a gear (32) that meshes with this is attached to the motor (4). ), (32) through seven-ta (4)
It is driven by and rotates as a unit.

(70) and (71) are arm members and motors that drive them; the rotation shaft (72) of the arm member (70) passes through one empty container (14), and the gears (76), (77) It is connected to Tanabata (71) through. The base (6) of a pair of electron beam sources (61 ((61), (62))
th).

(62b) is the guide protrusion (78) of the arm member (70),
(7!J) is slidably engaged. At this time, both beam sources (61) and (62) are attached so that the longitudinal direction of each beam coincides with the longitudinal direction of the arm member (70).

The lower end of the rotating shaft (72) is provided with a beam source moving mechanism (described later).
An encoder (73) is attached via (90).

(74) is a comparison circuit to which a reference rotation position information signal of the turntable (2) is supplied from the encoder (8), and a reference rotational position information signal of the turntable (2) is supplied from the encoder (73).
A rotational position information signal is supplied.

The output of the comparator circuit (74) is supplied to the motor (71) via a drive amplifier (75).

(90) is a beam source moving mechanism, and arm member (70)
is integrally attached to the other end of the rotating shaft (72) of the rotary shaft (72).

A motor (91) of a beam source moving mechanism (90) is connected to a drive shaft (93) disposed within a rotating shaft (72) via a clutch (92). (Q4), ('1J5)
are moving screws, each of which has an electron beam source (61
), (62) are screwed onto the bases (6+b) and (62b). A drive gear (96) is attached to one end of the drive shaft (93), and a driven southern gear (97) meshes with the drive gear (96).

(98) are attached to the moving screws (!J4.) and (95), respectively. Thus, both beam sources (61),
(62) are disposed symmetrically with respect to the rotation axis (72) of the arm member (70) and are configured to move symmetrically with respect to the rotation axis (72).

The operation of this embodiment is as follows.

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

(12) at the same position, for example, on the turntable (
The moving motor (91) is connected to the moving screw (9) via the clutch (92) to the gears (97) and (98) so as to irradiate the second divided area that is the second farthest from the center of the moving screw (9).
4) , (95) and drive the electron beam (61) so as to face the second divided area of the wafer (11). At the same time, the mask lifting/lowering rotation mechanism (23) is operated, and after the mask (2o) has been raised, the motor (25) is appropriately rotated to open the second window (2) from the periphery of the mask (2o).
1b') facing the second divided area of the wafer (11), and the mask (2o
) is lowered and returned, the mask (20) is attached to the wafer (1
1) and (12) are pressed evenly to fix each to the turntable (2), and the mask (20) is clamped while the wafers (11) and (12) are securely held.

The clutches (26) and (2) are disengaged, and the wafer (11) is preheated by the infrared pair (12) through the circular opening (2a) of the turntable (2), and then the turntable (2) is turned on. When the turntable (2) reaches a constant speed rotation state under the control of the rotation control circuit (9) and the emission of the linear electron beam (5) from the electron beam source (61) starts. , the first wafer (11) is at the position indicated by the circle (la) in FIG. 3. At this time, the longitudinal direction (83a,) of the linear electron beam source (61) (81
a) 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 -2
, (01, Yo, F, J (lb)
7. Move to the position indicated by 1 yen (1c).

During this period, driven by the motor (71), the electron beam source (6[) rotates counterclockwise around its rotation center CEO at the same speed as the turntable (2),
In FIG. 3, after passing through the position indicated by area (6b),
Move to the position where it is blocked in area (6c).

The manual direction (83c) of the area (6c) is the wafer (lc)
(81C) and the center of the turntable (2) (2c)
) and becomes parallel to the curve (82c).

As mentioned above, the electron beam source (61) synchronizes with the turntable (2) and emits the same J ((6a) to (6c)
) The irradiation rays (5d), (5e), (5f) by the linear electron beam (5) emitted from Since it is parallel to the radius vector of table (2),
The irradiation density of wafer (1) J2 becomes uniform.

By the way, if there is no beam mask (20), the irradiation region fIl'i of the electron beam is illuminated from the irradiation start end (5d)! 11 The collection of irradiation rays from moment to moment up to the final γ end (5f), with the uneven intensity of the edges of the beam in the longitudinal direction removed, forms a wide arc as shown in Fig. 4, and then Both the edge (84) and the upper edge (85) are connected to the center (2C) of the turntable (2) and the electron beam #! It has a radius of curvature equal to the distance 1i1tR from the rotation center C6G of +6+.

However, the above-mentioned irradiation region regulated by the beam mask (20) is equal to the projection (21p) of the window (21) of the mask (20) onto the wafer (1). As shown in Figure 4, the long side of the projection (2ip) is an arc (84)
The shape of the window (21) is set so that it does not intersect with and (85). In this way, the window (21) removes the uneven intensity at the rise and fall of the irradiation of the linear beam (5) and at both edges in the longitudinal direction, and the irradiation energy density within the irradiation regulation area is uniform. become .

Even after the irradiation of the second divided area of the first wafer (11) is finished, the turntable (2) continues to rotate at a constant speed to
The wafer (12) comes under the electron beam source (6) together with the window (22b) of the beam mask (20). At this time, the arm member (70) also
) (rotated 180° so that the electron beam source (62) occupies the position indicated by region (6a) in FIG. 3. The linear beam is oriented in its longitudinal direction Therefore, in the case of this embodiment, the arm member (70) to which the electron beam source (6) is attached can be continuously rotated, and its rotation control becomes extremely simple. ) is supplied via a slip ring.

Note that a microcomputer may be used to control the rotation of the motors (71) and (4).

When the first electron beam irradiation on both wafers (11) and (12) is completed, the mask (20) is moved up again by the mask lifting mechanism (23) without stopping the rotation of the turntable (2), and the clutch is released. (26), rotate the motor (25) appropriately, and open the window (21a) next to m (ztb) of the mask (20).
A mask (20) is placed so as to face the first divided area of 1).
Rotate 45° clockwise. At the same time, the clutch (92) of the beam source moving mechanism (90) is engaged, and the
1) as appropriate, and tighten the moving screws (4) and (95
) to drive both beam sources (6t).

(62) is moved symmetrically with respect to the rotation axis (72) in a direction approaching the rotation E'[1I (72) of the arm member (70).

The second beam irradiation regulation area (dashed line (2) in Figure 4)
2S) to be adjacent to the first time, the moving distance -11 is the window (21) of the beam mask (20).
) is set equal to the width W of Thereafter, electron beam irradiation is repeated in the same cycle as described above, so that the entire surface of the wafer can be uniformly processed.

By the way, as described above, the radius of curvature of the upper and lower edges of the wide, i-arc-shaped irradiation area on the wafer to be processed is equal to the distance R between the respective rotation centers of the turntable and the electron beam dfd. When the rotation angle 2θ of the turntable and beam source during one beam irradiation period is constant, the arc length of the irradiation area is the distance between the rotation centers! If 1lttR has a large culm length, the irradiation area becomes narrower and the number of irradiations per wafer can be reduced.

In addition, as the distance between the center of the rotation table and the electron Y-h source (7) increases, the shape of the irradiation area on the wafer becomes more rectangular, and the area that is shielded by the beam mask becomes can be reduced.

In the above-mentioned actual hiji example, a pair of electron beams d6+ (6
t).

(62) was used, but an electron beam source (6) was attached to only one end of the arm member (70), an appropriate balancer was attached to the other end, and a drive motor (71), such as a step motor, was used. It is also possible to use one with excellent rise characteristics and rotate the electron beam source (6) clockwise during the electron beam pause period.

In order to perform the required constant speed rotation even in such reciprocating rotation, it is preferable to provide a rising period and a falling period before and after the required constant speed period.

In this case, the mask (20) has one set of windows (21a).
) to (21d') may be arranged in a spiral shape, for example, at angular intervals of 90°.

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

〔Effect of the invention〕

As described in detail above, according to the present invention, the linear energy beam source is rotated nine times equal to the rotation angle of the rotary table on which the object to be processed is placed, and the beam, red, is moved in the radial direction of the rotary table. In response to the movement of the beam source, a wide irradiation area of the object to be processed is regulated by appropriately rotating an irradiation area regulating means having a plurality of rectangular openings arranged in a spiral shape. Therefore, it is possible to connect the irradiation control areas by each rectangular aperture on the object to be processed, and to make a simple beam 71I.
While using the I+transfer J mechanism, the entire surface of a large-diameter object can be uniformly irradiated with a small number of irradiations.

[Brief explanation of drawings]

1 and 2 are a small plan view and a block diagram of an embodiment of the linear energy beam irradiation device according to the present invention, and FIG.
1 and 4 are route diagrams for explaining the present invention; FIGS. 5 and 6 show an example of a conventional linear energy beam irradiation device; It is a route map for explaining the conventional device 'i'J'. (2) is a turntable, (61, (61), (
62) is a linear energy beam, (20) is a beam mask, (23) is a mask lifting/lowering rotation mechanism, (5■) is a mobile phase sweater, (71) is a beam d41 rotation motor, (9
0) is a mechanism for moving the beam df.

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 that irradiates the object with the linear energy beam, the irradiation beam of the linear energy beam on the object to be processed is rotated about one point in the radial direction of the rotating table as the rotating table rotates. an irradiation beam rotation means for rotating an amount equal to the rotation angle of the table; a beam source moving means for moving the linear energy beam source in a radial direction of the rotary table; and an irradiation area having a plurality of rectangular openings arranged in a spiral shape. A regulating means is provided, and the irradiation area of the linear energy beam surrounded by a pair of circular arcs and a pair of parallel lines formed by the irradiation beam is regulated by the irradiation area regulating means. Characteristic linear energy beam irradiation device.