TWI506680B - Substrate cooling means and irradiation ion beam - Google Patents

Description

Ion beam irradiation device and substrate cooling method

The present invention relates to an ion beam irradiation apparatus that irradiates an ion beam onto a cooled substrate.

For example, when a sharp and extremely shallow joint is formed on the tantalum substrate by ion implantation, it is preferable to amorphize the surface of the substrate. Further, in order to amorphize the tantalum substrate, it is necessary to keep the substrate temperature at a low temperature at the time of ion implantation.

Patent Document 1 discloses an example of an ion implantation apparatus 100A including a substrate cooling mechanism. Specifically, the ion implantation apparatus 100A injects ions by scanning the ion beam itself in a state where the substrate W is fixed at a predetermined position. As shown in FIG. 6, the ion implantation apparatus 100A includes a cooling body 9A that is fixed in a vacuum chamber VR. The side wall is provided so as to protrude into the vacuum chamber VR, and a refrigerant supplied from the outside is circulated inside; a heat dissipation plate 9B is fixed to the cooling body 9A; and a Peltier element 9C whose heat dissipation surface is fixed to The heat sink 9B has a heat absorbing surface fixed to the back surface of the electrostatic chuck 9D, and the electrostatic chuck 9D adsorbs the substrate W. By forming a temperature difference between the heat dissipation surface and the heat absorption surface by the Peltier element 9C, the heat of the substrate W is moved in the order of the electrostatic chuck 9D, the Peltier element 9C, the heat dissipation plate 9B, and the heat sink 9A, thereby The substrate W is cooled to about tens of degrees Celsius.

Further, the ion implantation apparatus in turn fixes the irradiation position of the ion beam, and the substrate is transported by the substrate transport mechanism to scan the ion beam on the surface of the substrate. In the ion implantation apparatus, a flexible resin pipe is provided between a wall body that forms a vacuum chamber and an electrostatic chuck that adsorbs a substrate on a substrate transfer mechanism in a vacuum chamber, and the resin is made to pass through the resin pipe to the electrostatic chuck. A cooling medium for cooling is supplied to cool the substrate. The reason why the flexible resin piping described above is used is because even When the substrate transport mechanism moves the substrate, the position of the pipe mating substrate can be deformed or moved, thereby preventing the piping for the refrigerant from being damaged when the substrate moves.

However, as shown in Patent Document 2, when the surface of the substrate is amorphized at the time of ion implantation, it is required to cool the substrate to an extremely low temperature of, for example, -40 ° C to -100 ° C.

However, according to the conventional substrate cooling mechanism described above, it is difficult to cool the substrate to the extremely low temperature described above. For example, in the ion implantation apparatus described in Patent Document 1, if a large current flows in order to form a temperature difference from room temperature to extremely low temperature between the heat dissipation surface and the heat absorption surface by the Peltier element, Joules are generated. The heat also increases, so that the cooling efficiency of the substrate is greatly reduced. Further, if the current flowing to the Peltier element is too large, the limit point at which the temperature of the substrate cannot be lowered again is reached, so that the monomer of the Peltier element can only be cooled to -20 °C as described in Patent Document 1. -30 ° C or so.

On the other hand, it is conceivable that the substrate is cooled to an extremely low temperature by supplying the refrigerant cooled to a very low temperature to the electrostatic chuck of the adsorption substrate without using the Peltier element.

However, when the extremely low-temperature refrigerant flows through the resin piping, the temperature is lower than the cold end temperature of the resin, and the resin piping is brittle and loses flexibility. Therefore, when the substrate is moved by the substrate transfer mechanism while flowing the extremely low temperature refrigerant, the resin pipe is broken. On the other hand, when a metal pipe is used which does not change its characteristics even under extremely low-temperature refrigerant conditions, the pipe has substantially no flexibility and freedom, and the position of the substrate has to be fixed in order not to damage the pipe. If the position of the substrate is fixed, a region or the like which can irradiate the ion beam to the surface of the substrate is restricted, thereby impairing the degree of freedom in ion implantation.

Further, in the ion implantation apparatus described in Patent Document 2, the substrate is previously cooled to a predetermined temperature in the substrate standby chamber provided adjacent to the ion implantation chamber. Then, the pre-cooled substrate is sent to the ion implantation chamber, and ion implantation is performed without cooling the substrate during the irradiation of the ion beam.

However, in the substrate cooling method described in Patent Document 2, the temperature change of the substrate during the irradiation of the ion beam as described above is not considered, and the basis during the ion beam irradiation. The temperature of the plate may be in a state of being separated from a temperature suitable for amorphization. Therefore, there is a problem that the substrate characteristics after ion implantation do not reach the required characteristics.

In other words, the prior art does not perform the substrate temperature control for monitoring the heat given to the substrate by the irradiation of the ion beam, thereby causing a temperature rise, and suppressing the temperature at the time of the ion implantation as much as possible. Rise and keep the temperature of the substrate constant. In addition, since the technical problems have not been closely studied in the past, there is no disclosure of a specific structure and substrate cooling method suitable for rapidly cooling a substrate to a target temperature and maintaining the temperature of the substrate at a target temperature when a temperature change occurs in the substrate. .

Prior art literature

Patent literature

Patent Document 1: Japanese Patent Laid-Open Publication No. 2001-68427

Patent Document 2: US Patent Publication US7935942

In view of the above problems, an object of the present invention is to provide an ion beam irradiation apparatus and a substrate cooling method capable of cooling a substrate to an extremely low temperature such as -60 ° C to -100 ° C even when a substrate is cooled by using a refrigerant. The flexibility of the resin pipe through which the refrigerant flows is not impaired, and the substrate can be freely moved during ion beam irradiation, and the temperature rise of the substrate during the irradiation of the ion beam to the substrate can be suppressed, and the substrate can always be used during the ion beam irradiation. The temperature is fixed at the specified temperature.

That is, the present invention provides an ion beam irradiation apparatus that cools a substrate held by a substrate holding portion of a substrate transfer mechanism, the ion beam irradiation device including: a first cooling mechanism, and a heat exchange portion on the substrate and Heat exchange between the refrigerants; and a resin pipe for softening the refrigerant in the heat exchange unit; a second cooling mechanism for cooling the substrate by heat transfer; and a cooling mechanism control unit; At least when the target substrate cooling temperature of the substrate is equal to or lower than the cold end temperature of the resin pipe, the refrigerant passes through the second while flowing the refrigerant to the resin pipe at a temperature higher than the cold end temperature limit. Cooling mechanism cooling The substrate.

Further, the present invention provides a substrate cooling method for an ion beam irradiation apparatus that cools a substrate held by a substrate holding portion of a substrate conveyance mechanism, the ion beam irradiation device including: first cooling The mechanism includes: a heat exchange unit that exchanges heat between the substrate and the refrigerant; and a resin pipe that is flexible for flowing the refrigerant in the heat exchange unit; and a second cooling mechanism Cooling the substrate by thermal transfer, the substrate cooling method, at least when the target substrate cooling temperature of the substrate is below the cold end temperature of the resin pipe, the temperature is higher than the cold end temperature limit The refrigerant flows through the resin piping, and the substrate is cooled by the second cooling mechanism.

According to the above aspect, when the target substrate cooling temperature of the substrate is less than the cold end temperature of the resin pipe, the refrigerant having a temperature higher than the cold end temperature is passed through the heat exchange portion of the first cooling mechanism Cooling the substrate once, and performing secondary cooling by heat transfer of the second cooling mechanism for a portion that cannot be cooled to the target substrate cooling temperature by the first cooling mechanism, so that the substrate can be made The temperature is lowered to the target substrate cooling temperature.

In this case, since only the refrigerant having a temperature higher than the cold end temperature is passed through the resin pipe, the flexibility of the resin pipe is not impaired, and the substrate transport mechanism is supported even when the substrate is cooled to a very low temperature. When the position of the substrate is changed, the resin piping is not damaged. Therefore, the substrate can be freely moved by the substrate transport mechanism while cooling the substrate, and the ion beam can be irradiated onto the surface of the substrate in various manners.

In addition, since the temperature of the substrate is lowered to some extent after the substrate is cooled by the first cooling mechanism, the substrate can be transferred even if the second cooling mechanism does not transfer a large amount of heat from the substrate. Cool to the target substrate cooling temperature. That is, since the second cooling mechanism does not need to perform a lot of heat transfer work and is not required to have excessive cooling capacity, the substrate can be cooled to the target substrate cooling temperature using, for example, a conventional Peltier element.

In order to amorphize the surface of the substrate during, for example, ion implantation or the like, an extremely shallow connection is formed. In order to enable high-quality ion implantation, it is preferable that the target substrate has a cooling temperature of -60 ° C or lower.

As a specific structure for efficiently discharging the heat transferred from the substrate by the second cooling mechanism to the outside, the substrate can be cooled well, and the second cooling mechanism is a Peltier element. The heat absorbing surface of the Peltier element is in contact with the substrate holding portion, and the heat dissipating surface is in contact with the heat exchange portion.

In order to further increase the direct or indirect contact area of the heat exchange portion with the substrate held on the substrate holding portion, the first cooling mechanism is further enlarged by efficiently performing heat exchange between the refrigerant and the substrate. Preferably, the heat exchange portion includes: a gas storage portion that is a space between the substrate holding portion and the held substrate, and stores a gas when the substrate is cooled; a gas passage, And supplying a gas to the gas storage unit or discharging the gas from the gas storage unit; and the refrigerant circulation unit is in contact with at least a portion of the gas passage, and the refrigerant flows through the refrigerant circulation unit. According to this aspect, since the heat exchange between the refrigerant and the substrate can be performed not only by the substrate holding portion but also by the gas in the gas storage portion and the gas passage, even the first cooling mechanism can be cooled more efficiently. Substrate.

In order to efficiently discharge heat taken from the substrate by heat transfer of the Peltier element to the outside, the cooling efficiency of the Peltier element is maintained at a high state, and preferably, the Peltier element The heat dissipation surface is in contact with the refrigerant flow portion.

In order to increase the temperature of the substrate from the target substrate cooling temperature even when heat is applied to the substrate by, for example, irradiation of the ion beam, the target substrate cooling temperature can be immediately fed back to the target substrate, and the temperature is always maintained at the stated temperature, preferably, The ion beam irradiation device further includes a contact type temperature sensor that is in contact with a substrate held by the substrate holding portion, measures a temperature of the substrate, and the cooling mechanism control portion controls to cause the The temperature of the refrigerant in the first cooling mechanism is fixedly maintained at a target refrigerant temperature, and the second cooling mechanism is controlled such that the substrate measurement temperature measured by the contact temperature sensor and the target substrate The deviation of the cooling temperature becomes small.

Further, the present invention provides an ion beam irradiation apparatus for cooling a substrate held by a substrate holding portion of a substrate transfer mechanism, the ion beam irradiation device comprising: a first cooling mechanism provided between the substrate and the refrigerant a heat exchange portion of the heat exchange; a second cooling mechanism that cools the substrate by thermal transfer; a temperature sensor that measures a temperature of the substrate; and a cooling mechanism control portion that performs control such that the first cooling mechanism The temperature of the refrigerant is fixed at the target refrigerant temperature, and the second cooling mechanism is controlled such that the deviation of the substrate measurement temperature measured by the temperature sensor from the target substrate cooling temperature of the substrate becomes small.

Further, the present invention provides a substrate cooling method for an ion beam irradiation apparatus that cools a substrate held by a substrate holding portion of a substrate conveyance mechanism, the ion beam irradiation device including: first cooling a mechanism comprising: a heat exchange unit that exchanges heat between the substrate and the refrigerant; a second cooling mechanism that cools the substrate by thermal transfer; and a temperature sensor that measures a temperature of the substrate, the substrate cooling method The ion beam irradiation device controls such that the temperature of the refrigerant in the first cooling mechanism is fixedly maintained at a target refrigerant temperature, and the substrate cooling method causes the ion beam irradiation device to control the second cooling mechanism, The deviation of the substrate measurement temperature measured by the temperature sensor from the target substrate cooling temperature of the substrate is made small.

According to the above aspect, the second substrate is cooled by the first cooling mechanism, the substrate is cooled to the target refrigerant temperature, and the substrate is in a state of being fixedly maintained at a temperature near the target substrate cooling temperature, so the second The cooling mechanism controls only the fluctuation portion of the substrate temperature fluctuation held by the first cooling mechanism by secondary cooling.

Therefore, since the second cooling mechanism only needs to control a small temperature change, it is not necessary to increase the temperature control range, so that it is easy to set the responsiveness to be high. Therefore, even if the temperature of the substrate is raised by irradiating the substrate with the ion beam, for example, the second cooling mechanism can be immediately operated to suppress the temperature rise, and the substrate can always be used. The temperature remains fixed.

Further, since the temperature of the substrate can always be kept constant, the state of the surface of the substrate during the irradiation of the ion beam can be maintained in a desired state as compared with the prior art, and the substrate having better characteristics can be obtained.

In order to be able to immediately cope with the temperature change of the substrate, it is preferable that the second cooling mechanism is a Peltier element, the heat absorbing surface of the Peltier element is in contact with the substrate holding portion, and the heat dissipating surface and the heat exchange Contact.

In order to further increase the direct or indirect contact area of the heat exchange portion with the substrate held on the substrate holding portion, it is possible to increase the first cooling by efficiently performing heat exchange between the refrigerant and the substrate. Preferably, the heat exchange portion includes: a gas storage portion that is a space between the substrate holding portion and the held substrate, and stores a gas when the substrate is cooled; a gas passage for supplying a gas to or discharging the gas from the gas storage portion, and a refrigerant flow portion contacting at least a portion of the gas passage, wherein the refrigerant flows through the refrigerant flow portion.

The heat transfer from the substrate by the second cooling means is efficiently discharged to the outside, and the specific structure of the substrate can be well cooled. Preferably, the heat radiating surface of the Peltier element is in contact with the refrigerant flow portion.

In order to increase the temperature of the substrate from the target substrate cooling temperature even when heat is applied to the substrate by, for example, irradiating the ion beam, the substrate temperature feedback can be immediately controlled to the target substrate cooling temperature so that the substrate is always maintained at the target substrate cooling temperature. Preferably, the temperature sensor is a contact type temperature sensor that is in contact with the substrate held by the substrate holding portion, and measures the temperature of the substrate.

According to the ion beam irradiation apparatus and the substrate cooling method of the present invention, when the substrate is cooled to an extremely low temperature, the refrigerant having a temperature higher than the cold end temperature is passed through the resin piping, and the first cooling mechanism is passed through the first cooling mechanism. The substrate is once cooled, and the remaining cooling of the substrate is achieved by heat transfer of the second cooling mechanism, so not only It is possible to prevent embrittlement of the resin piping through which the refrigerant flows, and to cool the substrate to the target substrate cooling temperature.

Further, since the fluctuation portion of the substrate measurement temperature is feedback-controlled by the second cooling mechanism in a state where the temperature near the target substrate cooling temperature is fixed by the first cooling mechanism, the second cooling mechanism can be controlled. The range is narrowed, and it is easy to improve the responsiveness of the temperature control. Therefore, even when the temperature of the substrate rises due to the irradiation of the substrate by the ion beam, the substrate can be immediately cooled to the target substrate cooling temperature, and the temperature of the substrate can be fixedly maintained at the target substrate cooling temperature.

1‧‧‧Ion implantation chamber

2‧‧‧Linear motion mechanism storage room

3‧‧‧Substrate transport mechanism

4‧‧‧ next door

5‧‧‧First cooling mechanism

6‧‧‧Peltier element (second cooling mechanism)

7‧‧‧Cooling Mechanism Control Department

11‧‧‧Ion beam inlet

31‧‧‧Substrate holding unit (electrostatic chuck)

32‧‧‧Motor

33‧‧‧ ball screw

34‧‧‧ nuts

35‧‧‧Cable Guides

41‧‧‧Connection gap

51‧‧‧ Gas Storage Department

52‧‧‧ gas passage

53‧‧‧Refrigeration Department

61‧‧‧Heat absorption surface

62‧‧‧heating surface

71‧‧‧First Cooling Mechanism Control Department

72‧‧‧Second cooling mechanism control department

73‧‧‧Refrigerant Temperature Control Department

74‧‧‧Gas Control Department

311‧‧‧

100A‧‧‧Ion implantation device

3B‧‧‧lower structure

3R‧‧‧Rotating mechanism

3U‧‧‧superstructure

5A‧‧‧Hot Exchange Department

5B‧‧‧Resin piping

9A‧‧‧ Heater

9B‧‧‧heat plate

9C‧‧‧Peltier components

9D‧‧‧Electrostatic chuck

FS‧‧‧Cooling system

VR‧‧‧vacuum room

W‧‧‧Substrate

1 is a schematic perspective view showing the structure of an ion implantation chamber of an ion implantation apparatus according to an embodiment of the present invention.

Fig. 2 is an enlarged cross-sectional view showing the structure of the periphery of an electrostatic chuck of the substrate transfer mechanism of the same embodiment as Fig. 1;

Fig. 3 is an enlarged cross-sectional view showing a mounting structure of the touch sensor of the same embodiment as Fig. 1;

Fig. 4 is a functional block diagram showing a configuration of a substrate cooling mechanism control unit and the like in the same embodiment as Fig. 1;

Fig. 5 is a schematic view showing the concept of temperature control of the substrate in the same embodiment as Fig. 1;

6 is a schematic view showing a conventional ion implantation apparatus including a substrate cooling mechanism.

One embodiment of the present invention will be described with reference to Figs.

The ion beam irradiation apparatus of the present embodiment is the ion implantation apparatus 100. The ion implantation apparatus 100 irradiates the semiconductor substrate with an ion beam containing, for example, arsenic, phosphorus, boron, or the like as an ion species, thereby injecting the ion species. Further, the ion implantation apparatus 100 can perform low-temperature ion implantation in a state where the substrate W is cooled to a predetermined extremely low temperature, thereby amorphizing the surface of the substrate at the time of ion implantation, and forming an extremely shallow junction.

Further, the ion implantation apparatus 100 may correspond to a normal temperature ion implantation that injects a temperature at which the photoresist cooled to the surface of the substrate is not deformed by heat at the time of ion implantation.

As shown in FIG. 1, the vacuum chamber VR of the ion implantation apparatus 100 which is internally vacuum-retained is partitioned up and down by the partition wall 4. Further, the upper structure 3U and the lower structure 3B of the substrate conveyance mechanism 3 are disposed across the respective chambers, and the upper structure 3U and the lower structure 3B are connected by a connection slit 41 formed in the partition wall 4.

More specifically, the ion implantation apparatus 100 includes the substrate transfer mechanism 3 that holds the substrate W on the substrate holding portion 31 and appropriately changes the position and posture of the substrate W with respect to the ion beam; the ion implantation chamber 1, It is a chamber on the upper side of the vacuum chamber VR that houses the upper structure 3U of the substrate transport mechanism 3, and is configured to irradiate the substrate W with an ion beam; the linear motion mechanism housing chamber 2 is a chamber on the lower side of the vacuum chamber VR. The lower structure 3B of the substrate transfer mechanism 3 and a part of the resin supply pipes 5B for supplying the electric power supply wires and the refrigerant are accommodated, and the cooling system FS for cooling the substrate W held by the substrate holding portion 31.

The following sections are explained below.

The upper structure 3U of the substrate transport mechanism 3 mainly performs posture control of the held substrate W, and the lower structure 3B is used to move the held substrate W for horizontal movement of the ion beam. That is, the upper structure 3U is constituted by a rotating mechanism 3R that rotates about a vertical axis for rotation about a vertical axis, and the substrate holding portion 31 that detachably holds the substrate W. The substrate holding portion 31 is an electrostatic chuck that is rotatable about an axis perpendicular to the surface of the substrate W that is held. The vicinity of the substrate holding portion 31 constitutes a part of the cooling system FS for cooling the held substrate W.

The lower structure 3B is a linear motion mechanism composed of a motor 32, a ball screw 33, a nut 34, and a guide (not shown), and moves the upper structure 3U so as to cross the short side direction of the ion beam.

The upper structure 3U and the lower structure 3B are formed in the partition wall 4 The upper connection slits 41 are connected by a connecting member, and the upper structure 3U is also integrally moved by the linear movement of the lower structure 3B in the horizontal direction, thereby moving the substrate W held on the substrate holding portion 31. Further, the connecting member is connected such that the upper structure 3U and the lower structure 3B are independently rotated.

The ion implantation chamber 1 is a chamber having a substantially hollow rectangular parallelepiped shape, and an ion beam introduction port 11 for introducing an ion beam is formed at a central portion of a side surface thereof, and a band-shaped ion beam extending in the vertical direction is introduced into the inside. A substrate waiting chamber (not shown) is provided adjacent to the ion implantation chamber 1, and the substrate transfer mechanism 3 receives the substrate W from the substrate standby chamber, and transports the substrate W to the ion beam irradiation position to perform the substrate surface. Ion Implantation. The substrate W after ion implantation is carried out to a substrate carrying-out chamber (not shown) provided adjacent to the ion implantation chamber 1.

The linear motion mechanism accommodating chamber 2 houses a part of the lower structure 3B of the substrate transport mechanism 3, and more specifically, the motor 32 is disposed outside the linear motion mechanism accommodating chamber 2, that is, on the atmospheric side. The other ball screw 33, the nut 34, and the guide are housed inside the linear motion mechanism housing chamber 2. Further, the linear motion mechanism housing chamber 2 has a higher degree of vacuum than the ion implantation chamber 1.

The cooling system FS is constituted by a first cooling mechanism 5 that cools the substrate W by heat exchange between the held substrate W and the refrigerant, and a Peltier element 6 as a second cooling mechanism that utilizes heat from the substrate W. The cooling substrate W is transferred; and the cooling mechanism control unit 7 controls the operations of the first cooling mechanism 5 and the second cooling mechanism. In the following description, the perspective view of FIG. 1 and the enlarged cross-sectional view of the periphery of the substrate holding portion 31 of FIG. 2 will be described.

The first cooling mechanism 5 performs a so-called refrigeration cycle to constitute a refrigerant circuit such that the refrigerant is disposed in a cooler 54 (not shown in FIG. 1) outside the vacuum chamber VR, and the substrate disposed in the vacuum chamber VR. The heat exchange portion 5A on the holding portion 31 that performs heat exchange between the substrate W and the refrigerant circulates. In addition, the first cooling mechanism 5 is connected to the cooler 54 and the heat exchange portion 5A as shown in FIG. Among the pipes, the resin pipe 5B is used as the pipe extending to the heat exchange portion 5A at least in the vacuum chamber VR. The resin piping 5B has flexibility, and even if the position of the heat exchange unit 5A is moved by the movement of the substrate conveying mechanism 3, the movement can be followed to some extent without the movement. The movement of the substrate transport mechanism 3 is hindered. More specifically, the resin piping 5B passing through the linear motion mechanism housing chamber 2 and a cable (not shown) for supplying electric power from the outside to the substrate conveying mechanism 3, and signals for control The wires (not shown) are housed in the bellows-shaped cable guide 35, and are movable in accordance with the operation of the substrate transport mechanism 3 within a predetermined range. In addition, the resin piping 5B has a problem in that the resin has a problem that when it reaches a temperature lower than the cold end temperature, the embrittlement is increased and the flexibility is lost, and the substrate transport mechanism 3 is broken when it moves. In the present embodiment, only the refrigerant having a temperature higher than the cold end temperature is circulated. In addition, the cold-resistant limit temperature as described above is, for example, a temperature at which the manufacturer's recommended temperature is lowered or the flexibility is lowered, and the resin-made pipe 5B is damaged by the operation of the substrate transport mechanism 3, and the temperature is cold-resistant in the present embodiment. The limit temperature is set to -60 °C.

The heat exchange unit 5A includes a gas storage unit 51. When the function is described, as shown in FIG. 2, it is a space between the substrate holding portion 31 and the held substrate W, and the gas is stored when the substrate W is cooled. a gas passage 52 for supplying gas to or exhausting the gas from the gas storage unit 51, and a refrigerant flow portion 53 contacting at least a portion of the gas passage 52, and the refrigerant is in the refrigerant flow portion 53. In circulation. The arrangement of the respective members is arranged in the order of the substrate W, the gas storage portion 51, the substrate holding portion 31, the second cooling mechanism, and the refrigerant flow portion 53.

More specifically, the front end surface of the substrate holding portion 31 has a substantially thin annular protrusion 311, and the back surface of the substrate W is electrostatically attracted to the plane of the protrusion 311. Therefore, the inner peripheral side of the ridge 311 forms a space in a state where the substrate W is held, and this space serves as a gas storage portion 51 that stores a gas when the substrate W is cooled.

In the present embodiment, the gas passage 52 includes: a gas supply pipe, a The gas storage unit 51 supplies a gas, and a gas discharge pipe for discharging the gas from the gas storage unit 51. The gas supply pipe and the gas discharge pipe pass through the inside of the refrigerant flow unit 53, and the gas and the refrigerant are made. A heat exchange takes place between them.

The refrigerant flow-through portion 53 is formed in a substantially hollow flat cylindrical shape, and the refrigerant cooled by the cooler 54 flows into the refrigerant flow portion 53 through the resin pipe 5B, and the refrigerant temporarily stays inside the gas and is in contact with the gas. After the heat exchange, the resin pipe 5B is returned to the cooler 54 again.

The cooling action of the first cooling mechanism 5 will be described. When the substrate W is cooled, when the gas is stored in the gas storage portion 51, the substrate W disposed in the vacuum atmosphere is placed with a thermal conductor having no gap contact with the fine uneven shape on the back surface thereof, and the substrate W can be improved. Heat transfer efficiency. Therefore, since the refrigerant of the refrigerant flow portion 53 and the substrate W can be directly exchanged heat through the gas passage 52, it is assumed that heat conduction is generated even without the second cooling mechanism, and the substrate W can be cooled. In other words, the first cooling mechanism 5 can exchange heat with the substrate W even if it is separate. Further, in the present embodiment, the refrigerant flow portion 53 is also in contact with the substrate holding portion 3 via the Peltier element 6 which is a good heat conductor, so that the heat transfer can be cooled by the heat exchange. Substrate W.

Next, the second cooling mechanism will be described.

Unlike the first cooling mechanism 5, the second cooling mechanism does not cool the substrate W by heat exchange, but cools the substrate W by heat transfer from the substrate W to the outside of the substrate W. Here, the cooling by the heat transfer includes a cooling method in which the temperature of the object on the low temperature side can be further lowered by transferring heat from the object on the low temperature side to the object on the high temperature side without using the refrigerant. Further, in the cooling by the heat exchange of the first cooling mechanism 5, the substrate W is cooled only when the temperature of the refrigerant is lower than the temperature of the substrate W, so the temperature of the substrate W is not lower than the temperature of the refrigerant.

More specifically, the second cooling mechanism is a heat absorbing surface 61 and the substrate The Peltier element 6 provided in contact with the holding portion 31 and having the heat dissipating surface 62 in contact with the refrigerant flow portion 53 receives heat from the substrate W by the substrate holding portion 31 by electron flow, and then takes the heat taken away The refrigerant circulation portion 53 is discharged.

The cooling mechanism control unit 7 realizes its function by executing a program stored in the storage in a so-called computer including a CPU, a memory, an AC/DC converter, an input/output device, and the like. Further, when at least the target substrate cooling temperature of the substrate W is equal to or lower than the cold end temperature of the resin piping 5B, the cooling mechanism control unit 7 controls to flow the resin piping 5B to a temperature higher than the cold end temperature. The refrigerant cools the substrate W by the second cooling mechanism.

Further, as shown in FIG. 3, a contact type temperature sensor TS is provided which directly contacts the substrate W held on the substrate holding portion 31 from the back side, and measures the temperature of the substrate W. As shown in FIG. 2, the contact temperature sensor TS is provided at a plurality of locations so that the temperature of a plurality of portions of the substrate W can be measured, and the gas storage portion 51 and the back surface of the substrate W are passed from the substrate holding portion 31 side. contact. The cooling mechanism control unit 7 controls the first cooling mechanism 5 and the second cooling mechanism using the substrate measurement temperature obtained from the contact temperature sensor TS.

More specifically, as shown in the functional block diagram of FIG. 4, in the present embodiment, the cooling mechanism control unit 7 includes: a first cooling mechanism control unit 71 that controls the first cooling mechanism 5; and a second The cooling mechanism control unit 72 controls the cooling capacity of the second cooling mechanism. Further, in the temperature control of the refrigerant by the first cooling mechanism control unit 71, the substrate measurement temperature measured by the contact temperature sensor TS is used to determine the cold end temperature higher than the resin pipe 5B. The temperature is set to the target refrigerant value as the target value. On the other hand, the second cooling mechanism control unit 72 performs feedback control on the voltage applied to the Peltier element 6 by continuously feeding back the substrate measurement temperature of the contact temperature sensor TS, so that the target substrate cooling temperature is The deviation of the substrate measurement temperature becomes small.

Each control unit will be specifically described below. The first cooling mechanism control unit 71 includes: The refrigerant temperature control unit 73 controls the temperature of the refrigerant supplied to the refrigerant flow unit 53 to be the target refrigerant temperature, and the gas control unit 74 supplies the gas to or from the gas storage unit 51. 51 exhaust gas is controlled.

The refrigerant temperature control unit 73 switches its operation according to the target substrate cooling temperature, and sets the self-standard refrigerant temperature to be higher than the cold resistance limit temperature when the target substrate cooling temperature is equal to or lower than the cold resistance limit temperature of the resin piping 5B. When the target substrate cooling temperature is higher than the cold resistance limit temperature of the resin piping 5B, the target refrigerant temperature is set to the same temperature as the target substrate cooling temperature. Further, the refrigerant temperature control unit 73 controls each device of the refrigeration cycle such that the temperature of the refrigerant measured by the temperature sensor provided in the refrigeration cycle constituted by the cooler 54 or the like is maintained at the set target refrigerant temperature.

The gas control unit 74 controls such that a predetermined amount of gas is supplied to the gas storage unit 51 through the gas passage 52 while the substrate holding unit 31 holds the substrate W, and the substrate W is Before the substrate holding portion 31 is removed, that is, the gas is discharged from the gas storage portion 51 before the voltage applied to the electrostatic chuck is released, the pressure is substantially the same as that in the vacuum chamber VR, thereby preventing the electrostatic chuck. When the release occurs, the substrate W flies into the vacuum chamber VR due to the pressure difference.

The second cooling mechanism control unit 72 controls the voltage applied to the Peltier element 6 in accordance with the deviation between the target substrate cooling temperature and the substrate measurement temperature measured by the contact temperature sensor TS. Here, since the refrigerant temperature control unit 73 controls the temperature of the refrigerant to be fixed at the target refrigerant temperature, the second cooling mechanism control unit 72 controls the voltage applied to the Peltier element 6 so as to be equivalent. The heat generated by the difference between the target substrate cooling temperature and the target refrigerant temperature and the heat generated by the ion beam irradiation of the substrate W are thermally transferred from the substrate W to the refrigerant flow portion 53.

The operation at the time of cooling the substrate of the ion implantation apparatus 100 of the above configuration will be described with reference to the temperature change diagram of FIG. 5, and the case where the target substrate cooling temperature is lower than or higher than the cold resistance limit temperature of the resin piping 5B will be described.

When the target substrate cooling temperature is set to be lower than -60 ° C of -60 ° C which is the cold-resistant limit temperature of the resin piping 5B, the refrigerant temperature control portion 73 sets the target refrigerant temperature to be higher than the cold-resistant limit temperature. The temperature is, for example, -55 ° C, and the cooler 54 or the like is controlled so that the temperature of the refrigerant is fixedly maintained at the temperature. Further, the second cooling mechanism control unit 72 applies a voltage to the Peltier element 6 so as to correspond to the heat of the difference temperature of -100 ° C which is the target substrate cooling temperature and -55 ° C which is the target refrigerant temperature. Thermal transfer from the substrate W by the Peltier element 6. For example, the second cooling mechanism control unit 72 applies a voltage proportional to or related to a temperature difference to be set between the heat absorbing surface 61 and the heat radiating surface 62 to the Peltier element 6.

As shown in (a) of FIG. 5, during the non-irradiation of the ion beam to which the substrate W is not irradiated with the ion beam, the temperature of the substrate W is maintained at substantially -100 ° C by the operation of the first cooling mechanism 5 and the second cooling mechanism. When the substrate W is irradiated with the ion beam, the substrate measurement temperature measured by the contact temperature sensor TS rises from -100 ° C as shown in the ion beam irradiation of (a) of FIG. 5 due to the corresponding heat given to the substrate W. . At this time, since the magnitude of the deviation between the target substrate cooling temperature and the substrate measurement temperature is changed, the second cooling mechanism control portion 72 changes the application to the Peltier element 6 in response to the variation of the deviation. The voltage is applied and feedback is performed to maintain the temperature of the substrate at -100 °C.

That is, the Peltier element 6 continuously cools a set temperature difference portion of the target refrigerant temperature and the target substrate cooling temperature during the ion beam non-irradiation of (a) of FIG. 5, during the ion beam irradiation, The Peltier element 6 operates so as not only to cool the aforementioned set temperature difference portion but also to cool the fluctuation portion including the temperature rise so that the substrate W is maintained at the target substrate cooling temperature. Further, during ion beam irradiation, the first cooling mechanism 5 does not change the target refrigerant temperature, and is fixedly held at the same temperature as during the non-irradiation of the ion beam, since only the pair is disposed near the substrate W, and when the applied voltage is changed The Peltier element 6 capable of immediately changing the amount of cooling performs feedback control of the substrate measurement temperature. Therefore, even if a temperature change occurs, a delay does not occur substantially, and the temperature of the substrate W can be substantially fixed at -100 °C.

Next, an operation in the case where the target substrate cooling temperature is higher than the cold resistance limit temperature of the resin piping 5B will be described with reference to FIG. 5(b). Here, as a specific example, a case where the target substrate cooling temperature is -40 ° C and the cold resistance limit temperature is -60 ° C is considered.

In this case, the refrigerant temperature control unit 73 sets the target refrigerant temperature to -40 ° C which is the same temperature as the target substrate cooling temperature. Here, during the non-irradiation of the ion beam of (b) of FIG. 5, since there is substantially no heat flowing into the substrate W in the vacuum from the outside, the temperature of the substrate W is substantially only caused by the action of the first cooling mechanism 5. Keep at -40 ° C. On the other hand, during the ion beam irradiation, since the temperature of the ion beam substrate is raised by the irradiation of the pair of substrates W, the target substrate cooling temperature deviates from the substrate measurement temperature measured by the contact temperature sensor TS. Therefore, during the ion beam irradiation of (b) of FIG. 5, a cooling operation is performed by applying a voltage corresponding to the deviation to the Peltier element 6. That is, the cooling of the substrate W is continued with the refrigerant of -40 ° C with respect to the first cooling mechanism 5, and the temperature of the substrate is not measured, the Peltier element 6 is substantially not cooled during the non-irradiation of the ion beam, only in the ion beam The operation is performed when the substrate measurement temperature changes from -40 °C during the irradiation.

Since the Peltier element 6 provided in the vicinity of the substrate W as described above only uses the fluctuation temperature portion generated by the fluctuation of the target substrate cooling temperature as the object of cooling, it can be excellent even in the case of fluctuation. The responsiveness maintains the temperature of the substrate W at an extremely low temperature. More specifically, when the first cooling mechanism 5 is feedback-controlled by cooling the temperature rising portion due to the irradiation of the ion beam by the substrate W, the operation of the cooler 54 that is outside the vacuum chamber VR and away from the substrate W is reached. A large delay occurs when a change occurs and the result is displayed. Therefore, it is difficult for the first cooling mechanism 5 to perform temperature control of the substrate W so as to immediately eliminate the temperature rise. On the other hand, in the temperature rising portion, by performing temperature control on the Peltier element 6 provided in the vicinity of the substrate W in the vacuum chamber VR, the substrate W can be immediately cooled to the target substrate cooling temperature and fixed in a manner that does not substantially delay. At this temperature.

In the ion implantation apparatus 100 of the present embodiment, when the target substrate cooling temperature of the substrate W is equal to or lower than the cold resistance limit temperature of the resin piping 5B, the target refrigerant temperature is set to a temperature higher than the cold end temperature limit. The refrigerant flowing through the heat exchange portion 5A of the first cooling mechanism 5 higher than the cold end temperature is once cooled by the substrate, and is cooled by the first cooling mechanism 5 to the target substrate. The heat of the substrate W in the temperature portion is secondarily cooled by the heat transfer of the Peltier element 6, so that the temperature of the substrate W can be lowered to the target substrate cooling temperature.

At this time, since only the refrigerant having a cold-resistant limit temperature is passed through the resin pipe 5B, the flexibility of the resin pipe 5B is not impaired, and the substrate W is transported by the substrate while cooling the substrate W to a very low temperature. The mechanism 3 changes the position of the substrate W, and the resin piping 5B is not damaged. Therefore, the substrate W can be freely moved by the substrate transport mechanism 3 while cooling the substrate W to a temperature lower than the cold end temperature limit, and the ion beam can be irradiated to the surface of the substrate in various manners.

In addition, since the substrate W is cooled once by the first cooling mechanism 5 to lower the temperature of the substrate W to a certain extent, the Peltier element 6 can be transferred without transferring a large amount of heat from the substrate W. The substrate W is cooled to the target substrate cooling temperature without requiring an excessive capacity for the Peltier element 6.

In addition, since the temperature of the substrate W is also detected in real time by the contact temperature sensor TS during ion beam irradiation, and the Peltier element 6 is feedback-controlled according to the deviation between the target substrate cooling temperature and the substrate measurement temperature, It is also possible to substantially maintain the target substrate cooling temperature during ion beam irradiation.

Therefore, since the temperature control accuracy at the time of low-temperature ion implantation is improved compared with the conventional apparatus, the characteristics of the substrate W after the low-temperature ion implantation of the prior art can be obtained.

Other embodiments will be described below.

The ion beam irradiation apparatus of the present invention is not limited to the ion implantation apparatus 100, and includes, for example, an ion doping apparatus, an ion beam deposition apparatus, an ion beam etching apparatus, and the like. The concept of a device for use. Further, the substrate W is not limited to a ruthenium wafer, and the present invention can also be used for irradiation of an ion beam in the case of temperature management of a glass substrate, a semiconductor substrate, or the like. Further, when the glass substrate or the like is irradiated with the ion beam, the substrate can be held by the substrate holding portion of the substrate transfer mechanism by an adsorption method other than the electrostatic chuck.

In the embodiment, the second cooling mechanism uses the Peltier element 6, but the substrate W may be cooled by other methods of thermal transfer. For example, instead of a cooling mechanism formed by a semiconductor such as the Peltier element 6, a cooling mechanism that uses a non-same metal to exert a Peltier effect is used.

When the target substrate cooling temperature is higher than the cold end temperature limit, the cooling mechanism control unit 7 makes the target substrate cooling temperature coincide with the target refrigerant temperature, but the target refrigerant temperature may be set to a temperature higher than the target substrate cooling temperature. In other words, even when the temperature of the substrate W can be controlled by the action of the first cooling mechanism 7, the temperature of the substrate W can be changed without changing from the target substrate as shown in FIG. 5(a). The substrate W is also cooled by the second cooling mechanism in the state, and the second cooling mechanism also functions for the varying portion.

The Peltier element 6 can be used not only for the cooling of the substrate W, but also for heating the substrate W when the first cooling mechanism 5 excessively cools the substrate W for some reason.

That is, the second cooling mechanism control unit 72 can control not only the magnitude of the voltage applied to the Peltier element 6, but also the direction of the voltage. At this time, when a deviation occurs between the target substrate cooling temperature and the substrate measurement temperature, the temperature of the substrate W can be controlled using the control principle described in the above embodiment.

When the target substrate cooling temperature is set to be higher than the cold end temperature of the resin piping 5B and the responsiveness is not critical, the second cooling mechanism may be completely disabled, for the first cooling mechanism 5 Feedback control based on the deviation of the target substrate cooling temperature from the substrate measurement temperature is performed.

In the embodiment, the temperature of the substrate W is monitored in real time by the contact temperature sensor TS, and the temperature of the substrate W can also be measured by a non-contact temperature sensor. Line temperature control.

Further, various modifications and combinations of the embodiments may be made without departing from the spirit and scope of the invention.

1‧‧‧Ion implantation chamber

2‧‧‧Linear motion mechanism storage room

3‧‧‧Substrate transport mechanism

4‧‧‧ next door

11‧‧‧Ion beam inlet

31‧‧‧Substrate holding unit (electrostatic chuck)

32‧‧‧Motor

33‧‧‧ ball screw

34‧‧‧ nuts

35‧‧‧Cable Guides

41‧‧‧Connection gap

3B‧‧‧lower structure

3R‧‧‧Rotating mechanism

3U‧‧‧superstructure

5B‧‧‧Resin piping

VR‧‧‧vacuum room

W‧‧‧Substrate

Claims (8)

An ion beam irradiation apparatus for cooling a substrate held by a substrate holding portion of a substrate conveyance mechanism; the ion beam irradiation device comprising: a first cooling mechanism, comprising: a heat exchange portion, the substrate and the refrigerant Heat exchange between the two; and a resin pipe for circulating the refrigerant in the heat exchange portion to have flexibility; a second cooling mechanism for cooling the substrate by heat transfer; and a cooling mechanism control portion, at least When the target substrate cooling temperature of the substrate is equal to or lower than the cold-resistant limit temperature of the resin pipe, the refrigerant is passed through the second cooling while flowing the refrigerant to the resin pipe at a temperature higher than the cold-resistant limit temperature. The mechanism cools the substrate. The ion beam irradiation apparatus according to claim 1, wherein the target substrate cooling temperature is -60 ° C or lower. The ion beam irradiation apparatus according to claim 1 or 2, wherein the second cooling mechanism is a Peltier element, a heat absorbing surface of the Peltier element is in contact with the substrate holding portion, and a heat dissipating surface is The heat exchange unit is in contact. The ion beam irradiation apparatus according to claim 1 or 2, wherein the heat exchange portion includes: a gas storage portion which is a space between the substrate holding portion and the held substrate, and when the substrate is cooled a gas passage for supplying a gas to or discharging the gas from the gas storage portion; and a refrigerant flow portion contacting at least a portion of the gas passage, wherein the refrigerant is in the refrigerant flow portion Circulation. The ion beam irradiation apparatus according to claim 3, wherein the heat exchange portion includes: a gas storage portion between the substrate holding portion and the held substrate a space for storing a gas when the substrate is cooled; a gas passage for supplying gas to or exhausting the gas from the gas storage portion; and a refrigerant flow portion contacting at least a portion of the gas passage, The refrigerant flows through the refrigerant circulation unit. The ion beam irradiation apparatus according to claim 5, wherein the heat dissipation surface of the Peltier element is in contact with the refrigerant flow portion. The ion beam irradiation apparatus according to claim 1 or 2, wherein the ion beam irradiation apparatus further includes a contact type temperature sensor that is in contact with the substrate held by the substrate holding portion, and is measured a temperature of the substrate; the cooling mechanism control unit controls to maintain a temperature of the refrigerant in the first cooling mechanism at a target refrigerant temperature, and control the second cooling mechanism such that The deviation between the measured temperature of the substrate measured by the contact temperature sensor and the cooling temperature of the target substrate becomes small. A substrate cooling method, characterized in that it is used in an ion beam irradiation device that cools a substrate held by a substrate holding portion of a substrate transfer mechanism; the ion beam irradiation device includes: a first cooling mechanism, a heat exchange unit that exchanges heat between the substrate and the refrigerant, and a resin pipe for allowing the refrigerant to flow through the heat exchange unit to have flexibility; and a second cooling mechanism that passes heat Transferring and cooling the substrate; the substrate cooling method is such that at least when the target substrate cooling temperature of the substrate is below the cold end temperature of the resin pipe, the refrigerant is heated at a temperature higher than the cold end temperature The substrate is circulated through the resin pipe, and the substrate is cooled by the second cooling mechanism.