JPS62188336A - Method of automatic loading and unloading of wafer on susceptor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for automatically loading and unloading semiconductor wafers on a susceptor used in a chemical vapor deposition or CVD reactor.

During the manufacturing process of integrated electronic circuits, there is a step of epitaxially growing a layer of atoms (eg, silicon) on a semiconductor wafer (eg, silicon) to create P-type and n-type conductor regions. The epitaxial layer is grown by thermally decomposing SiH4 and chemical vapor deposition of silicon atoms onto the wafer. This process is generally carried out in a barrel reactor at fairly high temperatures (eg 1100-1200°C).

A typical body reactor for epitaxial layer growth has a pell jar containing a susceptor having multiple sides, each side forming one or more shallow pockets in which a semiconductor wafer is placed. has been done. A heat source is installed around the outer circumference of the Pel jar to thermally decompose the SiH4 introduced into the Pel jar. As this SiH4 decomposes, the susceptor is rotated, thereby uniformly growing silicon atoms on the wafer in each pocket.

Conventionally, loading and unloading of wafers onto and from a susceptor was performed manually by an operator holding the wafer with tweezers.

For this reason, during this manual operation, the wafer may be damaged or even fall accidents may occur. For this reason, manufacturing yield deteriorates and costs increase.

Therefore, a method for automatically loading and unloading wafers on a susceptor is desired.

The above-mentioned problems are substantially solved by the present invention, which automatically loads and unloads wafers on a susceptor. The method according to the invention first involves engaging a wafer at a wafer loading station with at least one suction means of a pick-up device. after that,
The pickup device is moved from the wafer load station and the susceptor is positioned adjacent the pickup device. Thereafter, the pickup device is moved toward the susceptor, and the wafer is placed on the susceptor.

Once the wafer is placed on the susceptor, the wafer is disengaged from the pick-up device.

Another method according to the invention automatically unloads the wafer from the susceptor.

In this unloading method, a susceptor is first positioned adjacent to a pickup device having suction means. Then, after engaging the wafer and the suction means,
The pickup device is moved from the susceptor to a wafer unload station, where the wafer is disengaged from the pickup device and the wafer is loaded into the wafer unload station.

The susceptor loading and unloading steps can be accomplished together by a single structure that achieves this objective.

Figure 1 is a side view of a CVD (chemical vapor deposition) reactor 10, which in the preferred embodiment is located in Santa Clara, California, United States.
C1ara) Applied Materials (Appl
It consists of a 7810 type reactor manufactured by IED Materials. Reactor 10 comprises a vessel 11 which has an opening 11a at its top. Container 11
A plurality of wafers 12 to 1 are subjected to CVD processing within
A layer of atoms is epitaxially grown on each of the two. These wafers 12-12 are placed in a plurality of spaced apart pockets 14-14 on a wafer support member, i.e., a susceptor 16.
are held in each. The susceptor 16 is a multi-sided fuselage, typically having six sides;
Each side has two vertically spaced pockets 14-14.
has. The susceptor 16 is typically made of a material, such as graphite, which is sensitive to RF (radio frequency) fields, so that it is inductively heated within the vessel 11. Note that if the susceptor 16 is heated within the container 11 by another method, the susceptor 16 may be made of a material that is not sensitive to RF fields.

The susceptor 16 is fixed to the lower end of the rod 20,
The upper end of this rod 20 is attached to a disk 2 by a hook (not shown).
It is removably attached to 2.

This disk 22 is attached to an arm 24, and this arm 2
4 is slidably attached to the reactor 10 and can be moved in the vertical direction. A means (not shown) for raising and lowering the arm 24 is provided in the reactor 10, thereby raising and lowering the susceptor 16.
is inserted into the opening 11a of the container 11 and withdrawn therefrom. The disk 22 at the upper end of the rod 20 is connected to the arm 2
4 is lowered to insert the susceptor 16 into the container 11, and then seals the opening 11a of the container 11. A motor (not shown) is provided on the disk member 22, and this motor rotates the rod 20 and the susceptor 16.

Conventionally, wafers 12-12 are manually inserted into pockets 14-14 on sides 18-18 of susceptor 16 using tweezers.
14 and was taken out from there. Manual handling of the wafers 12-12 in this manner may damage the important surfaces of the wafers, rendering them unusable, and may even cause the wafers to be dropped and damaged.

This wafer damage during wafer handling reduces manufacturing yield and increases production costs.

In order to avoid damage caused by manually transferring the wafers 12-12 to the susceptor 16, a loading and unloading device 2 is installed.
6 was developed to automate wafer handling.

This loading and unloading device 26 has a transport vehicle 28 which is parallelepiped in shape and has castors 30 to 30 at the bottom for rolling movement to the CVD reactor 10. And you can leave it as well. A plurality of pillars 32 - 32 extend upward from the four corners of this carrier 28 and support a shelf 34 .

This shelf 34 is slightly higher in height than the reactor 11 of the reactor 10, and as shown in FIGS.
A projecting portion 35 integrally extends outward in the horizontal direction.

As shown in FIG. 2, the overhanging portion 35 has a tapered inner surface 35a and an outer portion 35b. are parallel to each other. Further, the outer portion 35b of the overhang portion 35 is set larger than the opening 11a (FIG. 1) to the reaction vessel 11. After the susceptor 16 is pulled out from the reaction vessel 11, the overhang 35 is inserted into the reactor 10 as shown in FIG.
When the carriage 28 is positioned so as to overhang the overhang, the outer portion 35b of the overhang (see FIG. 2) will be located over the opening 11a to the reaction vessel. As shown in FIG. 2, three beams 36 to 3 are provided to support the overhang 35.
6 extends from the lower surface of the shelf 34 and is in contact with the lower surface of the overhang 35 .

A pair of alignment members 37 spaced apart from each other in FIG.
37 are fixed to opposite sides of the reactor 10 so as to extend outward. These alignment members 37.37 capture the sides of the tapered inner part 35a of the overhang 35 and position the outer part 35b of the overhang above the opening 11a (see FIG. 1) to the reaction vessel 11. It serves as a guide.

Each of the pair of clasps 38.38 is attached to a separate edge of the tapered inner surface of the overhang 35 and each of the alignment members 37.
．． It engages a pair of rollers 39 and 39 that protrude upward from 37. Carriage 28 is thus held securely engaged with reactor 10.

In FIG. 1, platform 40 is a fluidic silicone 4
These cylinders 44,44 are mounted vertically on the platform 40, supported above the ledge 35 by respective shafts 42 of 44,44. plant home 4
0 is raised a small distance (e.g., 1 inch) from the ledge 35 when the shaft 42.42 of the cylinder 44.44 is extended as shown in FIG. As shown in FIG. 2, a limit switch 45 is attached to the tapered inner side 35a of the overhang 35.
detects that platform 40 is in the raised and lowered positions.

As shown in Figures 1 and 2, the plant home 40
has a table 46 rotatably supported on the upper surface of platform 40. When the susceptor 16 is pulled out from the container 11 and the carrier 28 is adjacent to the reactor 11 and the overhang 35 is positioned above the reactor 11, the table 46 is under the susceptor 16. As shown in FIG.
The gear 48 is connected by a drive chain 50 to a motor 52 mounted on the platform 40. A sensor 54 mounted on platform 40 detects the position of table 46 as it is rotated by motor 52.

A pair of upright guides 56,56, each 1 to 2 inches in height, are disposed on the table 46 to limit lateral movement of the pair of sides of the susceptor 16. Suscepta 16
is suspended from the disk 22 by a hook, so when it is pulled out from the container 11, there is a risk that it will swing like a pendulum and go over the table 46. is prevented. On table 46,
Another pair of guides 58.5B, which are somewhat lower in height, are arranged, and these guides 58.58 engage another pair of sides of the susceptor 16 when the platform 40 is lifted and contacts the base of the susceptor 16. match.

Robot 60 A robot 60 is provided on the platform 40,
This robot 60 has an arm 62.

The arm 62 is rotatably supported on an upright cylindrical base 64 that is fixed to the platform.

The attachment position of the base 64 to the platform 40 is determined as follows. That is, the arm 62 is configured to rotate along an arc (not shown) having a radius that is coaxial with the radius of the table 46. Arm 6
2 is said to be in the "reference position" when it is coaxial with the radius of table 46, that is, in a straight line, as shown in FIG.

FIG. 3 shows the robot 60 in detail, with the arm 62 having first and second arm portions 66 and 68, both of which are provided with through holes to reduce mass. It is made from a rod with multiple holes. One end 68a of the arm portion 68 is cut at an angle, and one end 68a of the arm portion 68
From then on, there is a tab 6 located halfway between the top and bottom of the arm.
9 extends outward and enters a slot 70 at the outermost tip of one arrowhead-shaped end 70a of the arm portion 66.

Pivot pin 71 rotatably attaches tab 69 to slot 70 such that arm portion 68 rotates about arm portion 66 between a horizontal position (shown in solid lines) and a vertical position (shown in phantom lines). move between The pivot pin 72 pivotably connects a tab 73 located at the top of one end 68a of the arm portion 68 to a shaft portion 74 of a double-acting fluid cylinder 75, and this cylinder 75 is configured to extend horizontally. is attached within the arm portion 66. A limit switch 76a is attached to the arm portion 66, and this switch 76
a is actuated by the shaft portion 74 when the shaft portion 74 is retracted into the cylinder 75. Another limit switch 76b is attached to the end 70a of the arm section 66 below the tab 71, and this limit switch 76b is activated when the arm section 6B is pivoted to the vertical position.

- A circular plate 77 is attached to the bottom of the upper part 66 in close proximity to one end 77a, and this circular plate 77 is connected to the base 64.
It is rotatable on a flanged member 78 integral with the upper end of. A vertical shaft 80 is fixed to the arm portion 66 and extends downward from the arm portion 66, and the circular plate 76 penetrates the flanged member 78 and enters the base portion 64.

Bearings 82 and 84 connect shaft 80 to flange 78 and base 6, respectively.
It is rotatably supported with respect to 4. The shaft 80 is driven by a motor 88 via a speed reducer 86, which motor 88 is mounted on the bottom of the base 64. A rotary resolver (not shown) is coupled to the motor 88 and generates a signal representative of the angular position of the motor shaft and, therefore, the angular position of the robot arm 62.

Attached to flange 78 is a fluid cylinder 90 whose axis 92 extends upwardly parallel to axis 80. When the cylinder 90 is at rest (non-pressurized), the shaft 92 is not engaged with the retraction plate 77, thereby allowing the arm 62 to rotate. The shaft 92 is a cylinder 90
When the arm 6 is projected from the plate 77, the arm 6 engages with the opening 93 in the plate 77.
Lock the rotation of 2.

The robot 60 shown in FIG. 3 holds an end effector, that is, a gripper 94, at an end 95 of the arm 68 opposite to the end 68a.

This gripping body 94 has a vertical rod 96, and this vertical rod 96 has a pair of pins 9B, 9B parallel to each other and spaced apart from each other.

These pins 9B and 98 are respectively inserted into a pair of linear bearings (not shown) that protrude from the rod 96 and are fixed within the end 95 of the arm portion 68. A double-acting fluid cylinder 100 is mounted horizontally extending within the arm 68 and has an axis (not shown) attached to a rod 96 that directs the rod toward and away from the arm 68. Displace it in the direction away from it. A limit switch 10 is attached to the arm portion 68.
1 is attached, and this limit switch 101 has pins 98 and 98 that are attached to the grip body 9 due to the extension of the axis of the cylinder 100.
4 is actuated by the upper pin of pin 98.98.

a first pair of rods 102.102 parallel and spaced apart from each other;
A second pair of rods 103, 103 similar to
, is slidably housed within a second pair of linear bearings (not shown) and extends horizontally through the top and bottom of rod 96. End 102 of each rod 102.102 and 103.103
A stop portion (not shown) is provided near a and 103a to limit movement of the rod within the bearing of the rod 96. End 102b of each pair of rods 102.102 and 103.103
A pair of spiders 104 and 104 are attached to 103b and 103b, respectively. These spiders 104.104 are connected to a first pair of springs 106.106 and a second pair of springs 10, respectively.
7.107 from rod 96. Each spring 106.106.107.107.

are coaxial with rods 102.102 and 103.103, respectively.

FIG. 4 is a front view of the robot 60 of FIG. 3 taken along plane 4-4, with each spider 104 having a multi-aperture ring portion 108 with a number of apertures drilled therein. This ring part 10
8 is integrally provided with multi-opening arms 110 to 110,
These multi-opening arms 110-110 extend radially at regular intervals. Each arm 110 of spider 104 has a vacuum aspirator (suction cup) 112 that projects from spider 104 (out of the plane of FIG. 4). The radial distance between the center C of the ring portion 108 of the spider 104 and each vacuum suction device 112 is set to be slightly smaller than the radius of each wafer 12 in FIGS. 1 and 2. The radial distance of the suction devices 112-112 is determined as described above, so that each suction device 112 engages the front peripheral portion of each wafer 12-12 held in the susceptor 16 of FIG. be able to.

In FIG. 5, each suction device 112 has a truncated conical hollow upper part 116 and an integral cylindrical hollow lower part 118. The diameter of the cylindrical portion 118 of each aspirator 112 is slightly smaller than the diameter of the counterbore 119. Note that this hole 119 is bored in the bottom of each arm 110 and is coaxial with the opening 119a of the arm 110. The cylindrical portion 118 of each aspirator 112 has a notch 119b, which allows the aspirator 112 to engage the opening 119a. The counterbore 119 has a female thread carved therein, and is screwed into the male thread of the end 120a of the joint 120 with a protrusion. This joint 120 engages with an end 121a of a hose 121. The opposite end 121b of the hose 121 is connected to a vacuum pump 122 via a valve 123.

(silastic) Made from thermoset silicone, elastomer, such as E-silicone. This branded elastomeric silicone is chemically very pure and free of Na'', K'' that could contaminate the wafer 12.
, (J-, etc.), is non-abrasive, and is very thermally stable, making it very effective as a material for the suction devices 112-112.

In FIG. 3, the suction devices 112-112
If the susceptor 16 is not present, there is a risk of contamination. In order to avoid this contamination, a pair of detectors 123a and 123b are mounted at the top and bottom of the end 95 of the arm 68, preferably a 27301 type scanner, with a pulsed light source (not shown) and a light sensor (not shown). have.

When the arm portion 68 of the robot 60 is in a position facing the indexed side surface 18 of the susceptor 16, each detector 123
a and 123b face each of the susceptor pockets 14-14 (see FIG. 1).

At this time, if the wafer 12 is present in the pocket 14 facing one of the detectors 123a or 123b, the light emitted from the detector is reflected by the wafer and returns. However, when the wafer 12 is not present in the susceptor pocket 14, there is no reflected light from the pocket because the surface of the pocket is a matte surface and scatters the incident light.

Wafer Load Station 124 Shelf 34 in FIG. 2 supports a wafer load station 124 that receives new wafers 12-12.

In FIG. 6, wafer load station 124
has a cassette lift 41126, and this lift l112
6 is mounted within the shelf 34 through the rectangular opening 128. It consists of an elevator whose function is to raise and lower the installed wafer cassette carrier 130.

This carrier can be used and has a number of slots 131-131, each slot 131 supporting the edge of one new wafer 12-12.

A reciprocating (shuttle) robot 134 is mounted on the shelf 34 adjacent to the opening 128, and the reciprocating robot 1
34 carries each of the pair of wafers 12.12 to the carrier 130.
They are taken out one after another and conveyed to the reciprocating plate 134.

A reciprocating robot 134 has a base body 13 attached to a shelf 34.
6, and a pair of parallel and spaced apart shafts 138, 138 (only one shaft is shown) are fixed to the base body 136 and project upward. These axes 13
8.138 respectively pass through a pair of linear bearings (not shown) built into each of the pair of blocks 140 and 141. These blocks 140, 141 are stacked on top of each other. Further, the fluid cylinder 142 has a main body connected to the block 140 and a cylinder shaft connected to the base 136, and the fluid cylinder 142 has a main body connected to the block 140 and a cylinder shaft connected to the base 136.
6 by a small distance (374 inches). Fluid cylinder 143 has its body attached to block 140 and its cylinder axis attached to block 141 and raises block 141 slightly (eg, 0.020 inch) above block 140.

Block 141 has a pair of linear bearings (not shown),
These linear bearings are spaced apart from each other, extend horizontally through the block 141, and slidably house a pair of columns 144, 144, respectively. The end of each column 144.144 remote from the block 141 is connected to a horizontal arm 145.
installed on. This arm 145 is displaced laterally, ie toward or away from block 141, by a fluid cylinder 146. This cylinder 146
The main body is connected to the block 141, and the cylinder shaft is connected to the arm 145.

Arm 145 has a thin spatula 148 extending horizontally towards cassette carrier 130 . As shown in FIG. 8, a plurality of openings 149 and 149 are bored on the surface of the spatula body 148, and these openings 149
It communicates with a passageway 150 extending longitudinally within 48 . This passage 150 is connected to the vacuum pump 122 of FIG. 5 via a valve (not shown).

In FIG. 7, the reciprocating plate 134 is made from a metal (for example aluminum) slab, which slides on a fully polished integral shaft 151=151. These axes 15
1.151 are disposed within the slots 152 of the shelf 34, which are aligned radially with the base body 64 of the robot 60 as shown in FIG. In FIG. 8, a first fluid cylinder 154 has its body connected to the reciprocating plate 134 and its cylinder axis connected to the body of a second cylinder 156, which has an axis connected to the shelf 34. is fixed to. The function of the cylinder 154 is that the reciprocating plate 1
34 from its original position far away from the base body 64 in FIG. from the intermediate position of the slot 152 (FIG. 7) to the slot end closest to the base 64 of FIG.

A pair of tapered circular recesses 158, 158 (see FIG. 7) are located on the upper surface of the reciprocating plate 134, and the size of the recesses is as follows:
The centers of the wafers 12 and 12 are set to coincide with the center of the recess 158 when the wafers 12 and 12 are accommodated, respectively. Each recess 158 is located above a horizontal thrower 159 (FIG. 8) that extends into the reciprocating plate 134 from the leading edge 159a closest to the arm 145.

In FIG. 7, the respective centers C of both recesses 158 and 158
, C is approximately equal to the distance between the respective centers C and C of the spiders 104 and 104 in FIG.
The suction device 112.112 of 4.104 can engage the wafer 12.12 housed in the reciprocating plate 134.

A recess 160a is provided in each circuit portion 158, and the distance between the recess 160a and the center of the recess 158 is equal to the distance between the wafer 1
The radius is set smaller than the radius of 2. Each recess 160a is connected to the same detector 1 as the detectors 123a, 123b in FIG.
60b is built in, and this detector 160b detects whether or not the wafer 12 is present in the recess 158.

A notch 161 extends from the front edge 159a of the reciprocating plate 134 into each recess 158, and the size of the notch 161 is larger than the spatula body 14B so that the spatula body 148 can fit into the notch 161. It is set slightly larger.

As shown in FIG.
It communicates with the slot 159 of. Second pair of cutouts 1
62, 162 each represent the rear edge 163 of the reciprocating plate 134.
and into each of the recesses 158 and 158.

In FIG. 7, a twin mesh pulley member 164 and a single mesh pulley member 166 are separated from each other by a small distance within each notch 162 and are rotatably supported by the reciprocating plate 134. A rubber bell l-168 (eg, neoprene) is wrapped in a loop around the twin mesh shear member 164 and the single mesh mesh mesh member 166.

The height of the sheave members 164 and 166 within each notch 162 is determined as follows. That is, the height is determined so that a portion of the belt 168 comes into frictional contact with the lower surface of the wafer 12 (indicated by imaginary lines) within the recess 158, as shown in FIG.

In FIG. 8, a second rubber belt 17 (l) is wound in a loop around a double-wire armature member 164 and a drive sheave 172, and this drive sheave 172 is driven by a motor 174 attached to a reciprocating plate 134. This causes the motor 174 to move the sheaves 164 and 166 in the other notch 162.
The belt 168 wound around the belt 168 is rotated via a second bell 170.

In FIG. 7, a circular recess 175 is formed within each recess 158 of the reciprocating plate 134. As shown in FIG. This depression 175 is
Since it is located near the outer periphery of the recess 158, the wafer 12 is covered except when the flat edge 176 of the wafer is located above. Inside each recess 158, a detector 123a shown in FIG.
A detector 177 identical to 123b is provided, which detects when the flat edge 176 has passed over it.

FIG. 9 shows a schematic diagram of a control circuit 178, which controls a motor 174 that rotates a wafer 12 housed in one of the pair of recesses 158, 158. . An identical control circuit (not shown) is provided to control the motor that rotates the wafer 12 in the other recess 158. The control circuit 178 includes an amplifier 182 that amplifies the output signal of the detector 177 and sends it to the inputs of a pair of one-shot multi-by-break (hereinafter referred to as one-shot multi) 184 and 186. The one-shot multis 184 and 186 generate output pulses in response to positive and negative input pulses from amplifier 182, respectively.

The output of one shot multi 184 is sent to the reset (R) input of RS flip-flop 188,
The output of shot multi 186 is sent to the first input of OR gate 190. The Q output of the RS flip-flop 188 is connected to the second input of the OR gate 190. The output of OR gate 190 is also connected to the reset (R) input of RS flip-flop 192. R.S.
The Q output of flip-flop 192 is connected to the second OR gate 1
The second input of this OR gate 194 is connected to the Q output of the RS flip-flop 188.

The output of OR gate 194 is connected to the reset (R) input of each of a pair of RS flip-flops 196 and 198, respectively. The Q output of flip-flop 198 is connected to the input terminal of opto-isolator 200, whose ground terminal is connected to circuit ground.

Further, in the isolator 200, the power supply terminal S is connected to the positive terminal +V of a DC voltage supply source (not shown), and the negative terminal of this voltage supply source is connected to circuit ground. The positive terminal of the voltage supply is also connected to the motor 17 via a voltage dropping resistor 202.
The other terminal of the motor 174 is connected to the output terminal 0 of the opto-isolator 200.

Wafer Unload Station 203 In FIG. 2, a wafer unload station 'IQ 203 is mounted on shelf 34 for storing processed wafers. As shown in Figure 10,
The wafer unload station 203 may use a pair of wafer cassette lifts 181204 and 2062660CP type lifts.

Each cassette elevator 204 and 206 passes through a pair of openings in shelf 34, thereby allowing elevators 204, 20
6 is located within the circular arc drawn by the spiders 104 and 104 of the arm portion 68 when the arm portion 68 in FIG. .

Each of the cassette elevators 204 and 206 includes a conveyor that extends over a platform 208 at a predetermined height.
The platform 208 has a pair of endless rubber belts 210, 210 rotatably supported on each longitudinal side. Each belt 210.210
is located above platform 208, a portion of which supports a wafer (not shown). A motor (not shown) drives the bells 210 and 210 together, which transports the wafers 12 on the belts into the cassette carrier 212. Note that this carrier 212 is placed vertically on an elevator so that it can be raised and lowered.

In FIG. 11, all control of wafer load and unload apparatus 26 is provided by controller 216. In FIG. The controller 216 has a memory 218 and
18 stores a control program executed by the processor 220. An input/output interface 222 connects the processor 220 to an operator control display panel 224;
Accordingly, in addition to displaying the status of the load/unload device 26, manual operator commands are preferred. The input/output interface 222 also connects the processor 220 to limit switches 45.76a, 76b,
101, detectors 123a, 123b, 4 υ 160a, 160b, and rotation sensor 54, processor 220 receives input signals from each of these circuits.

The processor 220 has an input/output interface 222
When it receives an input signal from the memory 218, it generates a control signal according to a program in memory 218. These control signals are
Input/output from processor 220 Cain surface 22
2 to cassette elevators 130, 204, 206 and motors 52 and 88 to control their operation. Processor 220 also generates further control signals that are communicated to valve 12 via input/output interface 222.
3 and each valve 226.227.228.230.231.
Sent to 232.234.236.238. Accordingly, these valves draw cylinders 142.143.146.154.156.90 from a pressurized fluid supply (not shown).
．． Controls the flow of pressurized fluid to 75.100 and 42.42.

FIG. 12 shows a flowchart of a program stored in the memory 218 (see FIG. 11), and the processor 220 executes this program to load the wafers 12 to 12 on the susceptor 16 of FIG. Control unloading.

Calculation Histep (Step 240) When the operator inputs a command through the operator operation display terminal 224, execution of the program in the memory 218 is started, and step 240 is first executed to initialize the load/unload device 26. ing. device 26
At the start of operation, the platform 40 must be lowered, the arm portion 68 must be in a vertical position (that is, the position perpendicular to the arm portion 66), and the gripping body 94 must be retracted. Further, the arm 145 of the reciprocating robot 132 is connected to the base 1.
36 and must be spaced apart from the cassette elevator 126, and the position of the reciprocating plate 134 must be away from the base body 64.

During this step 240, each limit switch 45.
The states of 76a, 76b, and 101 are changed to the second state.
The positions of the platform 40 and robot arm 60 in the figure are examined. Another limit switch (not shown) that detects the position of the reciprocating robot 132 and reciprocating plate 134 is also checked.

If the initial conditions are not the desired state,
ff 126 is activated to achieve the desired initial conditions. Also, during this step 240, all registers within the processor 220 are cleared of past unnecessary data.

Suscept 16 on table 46 (step 2
42) After step 240, the susceptor 16 closes the valve 238 (
11) to pressurize cylinders 42, 42, table 46 is engaged (step 24).
2). In detail, the pressurization of the cylinders 42,42 causes the plant home 40 to rise, thereby bringing the table 46 (FIG. 2) into contact with the base of the susceptor 16. The guides 56.56 and 58.58 capture the bottom of the sides 18-18 of the susceptor 16 on the table 46 so that the susceptor 16 is accurately positioned relative to the robot 60. Accurately positioning the susceptor 16 with respect to the robot 60 in this manner is an essential step when using the robot to load and unload wafers 12-12 on the susceptor.

Step 244) Once the susceptor 16 has been captured on the table 46, this table 46 is indexed (step 244). When one of the susceptor side surfaces 18 to 18 is selected in this manner, this selected side surface coincides in position with the gripping body 94 of the robot arm 62 brought to the reference position. Processor 220 indexes table 46 by energizing motor 52 in accordance with signals from rotation sensor 54 .

几゛ Wafer unloading (step 246)
Next, the robot 60 is activated by the processor 220 to move the processed wafer 1 onto the index side 18 of the susceptor 16.
2. Unload 12 and unload station 2
03 (FIG. 10) (step 246). To explain this in detail, first, the processor 220 checks whether the pair of wafers 12.12 are present on the index side surface 18 of the susceptor 16 by detecting the output signals of the detectors 123a and 123b. . If wafer 12.
12 does not exist at all. Alternatively, if only one wafer is present, an error message is displayed on operator control display panel 224. All subsequent actions are suspended until the operator takes the appropriate action. On the other hand, if two wafers 12.12 are present on the selected susceptor side 18, valve 236 is actuated by processor 220 to pressurize cylinder 100 and remove rod 96 (see FIG. 3) from arm 68. Displace outward.

When this rod 96 is displaced to the left, the suction device 112 . 112 of each spider 104 . 104 of the gripper 94 slowly contacts the front periphery of each wafer 12 . At the same time, the valve 123 is activated,
When the vacuum pump 122 draws vacuum through each aspirator 112.112, the wafer 12.12 is moved to the aspirator 112.112.
is engaged with. When wafer 12.12 is engaged, cylinder 100 is pressurized to retract gripper 94 and release wafer 12.
．． 12 from the selected susceptor side surface 18.

At this point, the valve 23, which has been in operation and pressurized the cylinder 92 and locked the robot arm 62, is activated.
Since the arm 62 becomes inactive, the arm 62 becomes rotatable. Thereafter, when the motor 88 is energized, the arm 62
(see FIG. 2) is rotated counterclockwise a short arc distance toward wafer unload station 203. When the arm 62 stops, the arm portion 68 closes the valve 23.
4 and pressurizes the cylinder 75, it is rotated to the vertical position.

After the arm 68 has been pivoted to be perpendicular to the arm 66, the arm 62 is again rotated clockwise to lift each wafer 12, 12 held in the gripper 94 to the cassette elevator 204. and a pair of rubber belts 2 of 206
10.Move them to the upper position of 210 respectively. wafer 12
．． When 12 reaches the position described above, cylinder 90 is pressurized and locks arm 62. Immediately thereafter, the valve 123 is deactivated and the vacuum suction of each aspirator 112, 112 is cut off. The gripper 94 thus places a pair of wafers 12, 12 on the cassette elevators 204, 206, respectively.

Wafer Unload Station 203 (Step 248) Once the wafers 12 have been loaded as described above, the motors (not shown) of each cassette elevator 204, 206 are moved in response to the elevator conveyor belt 210.

210 (see Fig. 10), and the wafer (
(not shown) into the carrier 212 and into the top slot of the carrier. Then each elevator 204.20
6 raises each cassette carrier 212 in preparation for loading the next wafer 12 into the uppermost empty slot of the carrier. As mentioned above, configuring a pair of processed wafers to be accommodated in a respective cassette carrier 212 of each elevator 204, 206 is generally more desirable than accommodating multiple wafers in a single carrier. That's true. In this way, the wafers 12.12 in the upper and lower susceptor pockets 14.14 can be kept spaced apart or separate from each other.

Wafer 12 at load station 124,
(Step 250) During step 248, the wafer load station 124 is activated to prepare for unloading a new pair of wafers (step 250). This is done by sequentially transporting each of the wafers from the cassette carrier 130 to the reciprocating plate 134. The wafers 12.12 must also be successively aligned with respective recesses 158, 158 in the reciprocating plate 134. Initially, the recess 158 in the reciprocating plate closer to the substrate 64 (see FIG. 2) is located just opposite the cassette elevator 126, so that the wafer is placed in this recess.

The wafer 12 from the cassette carrier 130 is transferred to the elevator 1.
In order to place the valve 22 in the recess 158 facing the valve 26, first
8 is activated. As a result, the fluid cylinder 146 is pressurized, displacing the arm 145 laterally inward, that is, toward the block 141, and moving the spatula body 148 toward the cassette carrier 1.
30 under the lowest wafer 12. Next, the cylinder 143 is pressurized to move the block 141 into the block 14.
Raise it by an amount from 0 to 0, thereby increasing the spatula body 14
8 places the wafer 12 in the slots 131-1 of the carrier 130.
Lift from 31.

Next, cylinders 142 and 143 are pressurized and block 1
40 and 141 are lowered, thereby arm 145
descend. In this way, when the arm 145 descends,
The spatula body 148 is displaced through the notch 161 of the recess 158 facing the cassette carrier 130 to form the slot 159.
Go inside. When this spatula body 148 enters the slot 159, the vacuum suction by the passage 150 is cut off. When the spatula body 148 enters the slot 159 in this manner, the wafer 12 that has been attracted to the spatula body is placed in the recess 158 facing the cassette elevator 126.

After placing the wafer 12 in the recess 158, the cylinder 15
4 (see FIG. 8) is pressurized to displace the reciprocating plate 134 to align the remaining empty recess 158 with the cassette elevator 125. The remaining idle part 158 in the spatula body 148
Since the spatula body 148 and the reciprocating plate 134 are aligned with the notch 161 inside, there is no interference at all between the spatula body 148 and the reciprocating plate 134. Therefore, the spatula body 148 can be lifted from the reciprocating plate 134.

While the reciprocating plate 134 is being displaced by the cylinder 154 as described above, the wafer 12 already placed in one of the recesses 15B, 158 is rotated by the motor 174, and alignment of the wafer is performed. Motor 1
74 is controlled by a corresponding control circuit 178 (see FIG. 9) in response to a signal ("START") from processor 220. The above signal is sent to the set input of each flip-flop 188, 192, 198 via the input/output interface 222, and these flip-flops are set to control the motor 174. Flip-flop 198, when set, sends a logic "H" signal to the input of opto-isolator 200, which
00 energizes the motor 174 in response to this and moves the recess 158.
The wafer 12 inside is rotated.

As wafer 12 rotates within recess 158, detector 177
is exposed as the wafer flat 176 passes over this detector. The exposure of this detector 177 eliminates the reflected light returning from the wafer 12 to the detector 177, so that the output signal changes from logic rL (low) to logic rH (high).
Changes to

When the output of detector 177 changes from L to H, one shot multi 184 resets flip-flop 188.

Even though flip-flop 188 is thus reset, flip-flops 196 and 198 remain set because flip-flop 192 is still set. As long as flip-flop 198 remains set, optoisolator 200 remains triggered, motor 174 remains energized, and wafer 12 continues to rotate. As wafer 12 continues to rotate, exposure of detector 177 by wafer flat 176 ceases. When the detector 177 is covered by the wafer 12, the output signal of this detector changes from H to L and one
The output signal of the Shoshito Multi 186 is changed from logic rHJ to logic rLJ.

Since flip-flop 188 has already been reset by one-shot multi 184, a change in the magnitude of the output signal of one-shot multi 186 causes both flip-flops 198 and 196 to be reset. When the flip-flop 198 enters the reset state,
Optoisolator 200 stops energizing motor 174. In this way, the rotation of the wafer 12 is caused by the rotation of the wafer flat part 1.
76 just passes the detector 177. Flip-flop 196, when in its reset state, generates a logic rHJ signal at its Q output (shown as the DONE signal) indicating that wafer 12 in recess 158 is correctly aligned; The signal is provided to processor 220. By selecting the angular position of the detector 177 on the outer circumference of the recess 158, the alignment position can be adjusted for the wafer 12 within the recess.

When the alignment of the wafer 12 placed on the plate 134 is completed, the cassette carrier 130 on the elevator 126 is lowered. The reciprocating robot 132 is then operated in exactly the same manner as described above to pick up the next wafer 1 in the carrier 130.
2 into the empty recess 158 of the reciprocating plate. Thereafter, the alignment of the wafer 12 currently placed is performed in the same manner as described above. In this way, a pair of wafers 12.1
2 is successively loaded into the recesses 15B, 15B, and when the alignment is completed, the cylinder 156 in FIG. Move to the end of the slot 52 nearer to you.

Loading onto the susceptor 14 by the robot 60 (
Step 252) When the reciprocating plate 134 is moved toward the substrate 64, the robot 60 moves the wafer 12.12 of the reciprocating plate onto the susceptor 1.
6 (step 252). Wafer 12.1 placed on reciprocating plate 134
2 on the susceptor 161, the robot arm 62 is first unlocked. Thereafter, the motor 88 is energized and rotates the arm 62 clockwise to move it from the unload station 203 to the load station 124 to move the gripper 94 into the recess 158.1 of the reciprocating plate 134.
Align wafer 12.12 in 58.

Following rotation of arm 62, cylinder 9° is pressurized to lock arm 62. Processor 220 then detects detector 15Q in recess 158, 158 on reciprocating plate 134.
Check the status of a and 160a to find out whether either of the recesses is empty. If the recess 158.158
If the wafer 12 is not present in any of the positions, the gripper 94 is not operated any further and an error message is displayed on the operator operation display panel 224. In this way, contamination due to direct contact of the suction devices 112, 112 of the gripping body 94 with the reciprocating plate 134 is avoided.

On the other hand, if a wafer 12.12 is placed in each recess 158.158, the cylinder 100 is pressurized and the gripping body 94
bring it closer to the reciprocating plate. This allows spider 10
4.104 suction device 112.112 is recessed part 158.15
Contact wafer 12.12 in 8. At the same time, valve 1
23 is actuated to provide vacuum suction via each aspirator 112.112, causing the front periphery of the wafer 12.12 to engage the aspirator.

After the wafer 12.12 has been engaged by the suction device 112.112, the cylinder 100 is pressurized to retract the gripper 94 and then unlock the arm 67. Next, when the motor 88 is energized, the arm 62 is rotated clockwise and brought to a position slightly away from the reference position facing the susceptor 16 .

After the arm 62 stops rotating, the arm portion 68 is pivoted to be aligned with the arm portion 66. after that,
Rotation of the arm 62 is resumed, bringing the wafer 12.12 held in the gripper 94 opposite the pocket 14.14 of the indexing side 18 of the susceptor 16. When the wafer 12.12 faces the selected susceptor side 16, the arm 62
is locked.

Next, the cylinder 100 is pressurized, displacing the gripping body 94 from the arm portion 68 toward the susceptor 16, and displacing the gripping body 94 toward the susceptor 16.
The wafer 12.12 held at 4 is seated in a pocket (see FIG. 1) in the indexing susceptor side 18. Then, the vacuum suction of the suction device 112 is stopped and the wafer 1 is removed.
2. Remove the suction device from 12. After the wafer 12.12 is mounted on the susceptor 16, the gripping body 94 is attached to the arm 6.
8, the loading operation is completed. Upon completion of this load operation, processor 220 increments by one an internal register called the "load step" register.

Loading and Unloading (Step 254) After the loading operation is complete, the processor 220 determines that the susceptor 16 has been completely unloaded and that the new wafer 12.
It is checked whether or not it has been remounted on the susceptor 16.

To this end, processor 220 transfers the value stored in the load step register to side 18 of susceptor 16.
．． Compare with the number 18. If the stored value in the load step register is equal to the number of sides 18.18, then
Processor 220 controls the operator control panel 224 to terminate loading and unloading (step 256) before terminating execution of the program (step 258).
Let me know. Otherwise, each side 18.18 of the susceptor 16 is unloaded and a new wafer 1 is removed therefrom.
Step 2 until the re-roping of 2.12 is completed.
44-252 are repeated.

[Brief explanation of drawings]

1 is a side view of an apparatus according to the invention for loading and unloading wafers on a multi-sided susceptor of a barrel reactor; FIG. 2 is a plan view of the loading and unloading apparatus of FIG. 1; The figure is a side view showing the robot of the loading and unloading device shown in Fig. 2 in detail with a partial cross section. Fig. 4 is a front view showing the spider of the robot shown in Fig. 3. 4 is a cross-sectional view taken along plane 5--5 of FIG.
Diagram of wafer loading and unloading equipment
FIG. 7 is a detailed perspective view of a portion of the loading station; FIG. 7 is a plan view of the reciprocating plate of the wafer loading station of FIG. 6; and FIG. 8
9 is an electrical block diagram of a control device forming part of the wafer alignment system for aligning the wafers on the reciprocating plate of FIGS. 7 and 8; FIG. 1 is a detailed perspective view of a portion of the wafer unloading station of the loading and unloading apparatus of FIG. 1; FIG. The illustrated block diagram, FIG. 12, is a flow chart diagram of a program executed by the control device of FIG. 11 for controlling the loading and unloading device of FIG. 1−・−−−−−−−−・−・−wafer, 1
4 ----------Pocket, 16-・-susceptor, 1 B----1・~side, 40-・-
・Plant home, 46-・----table, 56
．． 58--Guide, 60--------
- one robot, 112-- vacuum suction device, 124-- wafer load station, 130-- wafer cassette carrier, 203-- -Wafer unload station. Applicant: American Telephone and Telegraph Cambunny full-page engraving (contents (no changes), 5υ 50

Claims (1)

[Claims] 1. A method for automatically loading a wafer into a susceptor, comprising the steps of: engaging the wafer with at least one suction means of a pick-up device at a loading station; and the wafer being engaged with the pick-up device. positioning the susceptor in the vicinity of the pickup device; and moving the pickup device toward the susceptor to place the wafer on the susceptor. and disengaging the pickup device from the wafer after the wafer is placed on the susceptor. 2. The susceptor has a plurality of side surfaces, each of which has a plurality of pockets, and the positioning step includes determining the susceptor and positioning the selected side surface adjacent to the pickup device at a reference position. A method according to claim 1, characterized in that the method comprises: 3. A method for automatically unloading a wafer from a susceptor, comprising: positioning the susceptor adjacent to a pick-up device having at least one suction means; and engaging the wafer on the susceptor with the suction means. with the wafer engaged with the pick-up device;
The method further comprises the steps of: moving the pickup device from the susceptor to a wafer unload station; and disengaging the wafer from the pickup device at the unload station. How to do it. 4. The susceptor has a plurality of side surfaces, each side having a plurality of wafer holding pockets, and the engaging and positioning step includes indexing the susceptor and positioning the selected side surface adjacent to the pickup device. 4. The method of claim 3, further comprising the step of: 5. A method for automatically unloading and loading a wafer on a susceptor, comprising: positioning the susceptor so that the wafer on the susceptor is adjacent to a pickup device having at least one suction means; and the wafer and the suction means. moving the pick-up device from the susceptor to a wafer unload station to release and receive the wafer at the wafer unload station; moving the wafer from an unload station to a wafer load station containing a new wafer; engaging the wafer at the load station with the suction means; and moving the pick-up device to the wafer load station. A method comprising the steps of: transferring the wafer from a station to the susceptor and loading the wafer thereon upon release from the suction means. 6. The susceptor has a plurality of wafers, and each step includes the unloading and unloading of the wafers on the susceptor.
6. The method of claim 5, wherein the method is repeated until the wafer is transferred to a wafer loading station and replaced with a new wafer from the wafer loading station. 7. The susceptor has a plurality of sides, and the step of positioning the susceptor includes positioning a bottom of the susceptor on the table such that the sides of the susceptor are held between a plurality of upright guides on an indexable table. 7. The method of claim 6, further comprising the steps of: capturing; and determining the table to position selected sides of the susceptor adjacent the pickup device. 8. The wafer susceptor engaging step includes the steps of bringing the front outer periphery of the wafer into contact with suction means of the pickup device, and vacuum suction by the suction means. 6
The method described in section. 9. The wafer/suction means engaging step includes the steps of bringing the front outer periphery of the wafer into contact with the suction means of the pickup device, and vacuum suction by the suction means. The method described in Section 6. 10. The method of claim 6, wherein the wafer engaged by the pick-up device at the load station is aligned prior to pick-up. 11. A method for loading and unloading a wafer on a multi-sided susceptor, comprising the steps of: capturing the lower side of the susceptor between a plurality of upright guides on an indexable table; and indexing the table to select the susceptor. adjoining the selected side surfaces of the susceptor to an aspirator holding pick-up device slidably mounted on the end of the robot arm; bringing the wafer into contact with the suction device and engaging the wafer with the suction device while vacuum suctioning the wafer; retracting the pickup device toward the robot arm; and moving the robot arm into the susceptor. and displacing the pickup device toward a wafer unload station, where the vacuum suction of the aspirator is discontinued, the wafer is released, and the wafer is unloaded. further rotating the robot arm in a first direction to move the pick-up device from the wafer unload station to a wafer load station for receiving a new wafer; protruding a pick-up device outwardly from the robot arm to slowly bring each of the plurality of wafers of the wafer load station into contact with a vacuum suction device of the pick-up device to engage the wafers; retracting the pickup device toward the robot arm; further rotating the robot arm in the first direction;
placing the pickup device adjacent to the indexing side of the susceptor; protruding the pickup device from the robot arm toward the susceptor to mount the wafer held by the pickup device onto the susceptor; A method comprising: ceasing vacuum suction by the aspirator; and retracting the pick-up device toward the robot arm. 12. The front outer periphery of each wafer on a selected side of the susceptor is gently contacted by the vacuum suction device of the pickup device.
The method described in section. 13. The method of claim 11, wherein the plurality of wafers at the load station engaged with the pick-up device are sequentially rotated for alignment prior to pick-up. . 14. A device for loading and unloading wafers on a susceptor, including a robot arm that is rotatably supported on a base body in a circular arc that includes a reference position, and a robot arm that is slidably attached to the end of the robot arm and is used for engaging the wafer. a pick-up device having suction means; means for projecting and retracting the pick-up device with respect to the robot arm; and a wafer loading station located within the arc traversed by the robot arm to receive new wafers. , a wafer unload station located within the arc traversed by the robot arm and accommodating processed wafers; and means for positioning the susceptor adjacent to the pick-up device when the robot arm is in a reference position. (a) moving the robot arm from the reference position to the unloading station so that the pickup device can transport the wafer on the susceptor to the unloading station and storing it there; and (b) ) the wafer is moved from the wafer unload station to the wafer load station, and (c) the wafer is moved from the wafer load station to the susceptor, and the pickup device transfers the wafer from the load station to the susceptor. 1. A device comprising: a means for enabling transportation; 15. The susceptor has a plurality of sides, and the susceptor positioning means includes an indexable table having a plurality of upright guides disposed below the susceptor and spaced apart by approximately the spacing of the susceptor sides; a platform for rotatably supporting an indexable table; and means for raising the platform to bring the indexable table into contact with a bottom surface of the susceptor and capturing a side surface of the susceptor by the guide of the table; 15. A device according to claim 14, characterized in that it comprises: 16. The arm of the robot includes: a first arm rotatably supported on the base body so as to draw an arc in a horizontal plane; a first position where the arm is coaxial with the first arm;
a second arm attached to an end of the first arm so as to be pivotable between a second position perpendicular to the arm; and a second arm that is pivotable between the first and second positions. 15. A device according to claim 14, characterized in that it comprises means for pivoting. 17. The wafer unloading station includes at least one cassette elevator, the elevator holding a cassette carrier for receiving and storing the wafer that has been contacted by the suction device of the pickup device. Apparatus according to claim 14. 18. The wafer loading station is a reciprocating machine having a cassette elevator for holding a cassette carrier containing a plurality of new wafers, and at least one recess for placing a wafer for pick-up by the pick-up device. 15. The apparatus of claim 14, comprising: a plate; and means for transporting wafers from the cassette carrier on the cassette elevator to a recess in the reciprocating plate. 19. The apparatus according to claim 18, wherein each recess of the reciprocating plate is provided with means for aligning a wafer placed therein. 20. The means for aligning the wafers includes means for rotating the wafer in each recess, means for detecting when the wafer in the recess is in a predetermined alignment state, and the rotating means in accordance with the detection means. 20. The apparatus according to claim 19, further comprising: control means for controlling. 21. A device for rotating a semiconductor wafer having a flat portion and positioning the flat portion at a predetermined alignment position, comprising: a plate having a recess large enough to accommodate the wafer and center the wafer; an elastomeric belt rotatably supported within the recess so as to be in partial contact with the wafer; means for driving the belt to rotationally drive the wafer; a detector installed in the recess, and control means for controlling the drive means in accordance with an output signal of the detector, wherein the amplitude of the output signal of the detector is set to a level of the wafer. A device characterized in that the area changes when the area crosses the detector.