KR20120062842A - Method and apparatus for cooling subject to be processed, and computer-readable storage medium - Google Patents

Abstract

Disclosed is a method of cooling a workpiece, which can suppress the occurrence of scratches on the back surface of the workpiece. This cooling method loads the to-be-processed object W on the to-be-processed object support pin 50 which supports this to-be-processed object W under the pressure of a vacuum process, and the to-be-processed object W is spaced apart from a cooling member. Supplying a cooling gas for cooling the substrate to a first flow rate, raising the pressure around the workpiece to a first pressure higher than the pressure of the vacuum treatment, and cooling the workpiece for a first time; and lowering the workpiece support pin. In the state where the object to be processed is loaded or approached on the cooling member, the cooling gas is supplied at a second flow rate that is greater than the first flow rate, and the pressure around the object is raised to a second pressure that is higher than the first pressure. The second time, the process of further cooling.

Description

TECHNICAL AND APPARATUS FOR COOLING SUBJECT TO BE PROCESSED, AND COMPUTER-READABLE STORAGE MEDIUM

The present invention relates to a method for cooling an object, a cooling device and a computer readable storage medium.

In the manufacturing process of a semiconductor device, processes, such as a film-forming process and an etching process, are performed under the pressure of a vacuum with respect to the semiconductor wafer (henceforth a wafer) which is a to-be-processed object. In the film-forming apparatus and the etching apparatus which perform such a vacuum process, in order to convey a wafer from the wafer cassette placed in air | atmosphere to a vacuum, a pressure conversion must be performed between atmospheric pressure and the pressure of a vacuum process. In development, this pressure conversion is provided between the wafer cassette, the film-forming apparatus, and the etching apparatus, and the pressure lock is performed in the load lock chamber.

By the way, the film-forming process, an etching process, etc. are processes with pressure of a vacuum process, and high temperature. The wafer carried out from the film forming apparatus or the etching apparatus is, for example, at a high temperature of about 500 ° C. If the wafer in a high temperature state is exposed to the atmosphere, the wafer may be oxidized, and if the wafer in a high temperature state is returned to the wafer cassette, problems such as melting of the resin wafer cassette may occur.

In order to avoid such a problem, the wafer may be waited until the temperature is lowered to no problem. However, throughput is lowered if it waits for the temperature of a wafer to fall. For this reason, as described in Unexamined-Japanese-Patent No. 2009-182235, in the load lock chamber, the cooling plate which has a cooling mechanism which cools a wafer is installed, and the wafer is cooled while returning to atmospheric pressure from the pressure of a vacuum process. It is done.

However, when the wafer is rapidly cooled, the wafer bends due to the difference in thermal expansion of the front and back of the wafer, and the center portion or the edge portion of the wafer is separated from the cooling plate. As a result, the cooling efficiency is lowered, and as a result, the cooling time is lengthened, or the wafer is exposed to the atmosphere while leaving the hot portion.

In order to prevent warpage of such a wafer from occurring, the rate of increase in pressure when the load lock chamber is returned to atmospheric pressure, the distance between the wafer and the cooling plate, that is, the height position of the wafer are managed. A prescribed purge recipe is prepared for each wafer temperature. However, the degree of deformation of the wafer also varies depending on the kind of film formed on the wafer. In addition, there are a large number of membrane types for each user, and it is extremely difficult to create an optimal fuzzy recipe for each membrane type.

In order to solve such a difficulty, Japanese Unexamined Patent Publication No. 2009-182235 provides a displacement sensor for detecting deformation of the wafer during cooling, and adjusts the pressure and the height position of the wafer while monitoring the warpage of the wafer during cooling. I'm trying to.

Currently, the cooling technology has advanced to the extent that the warpage of the wafer during cooling can be suppressed, as described in Japanese Patent Laid-Open No. 2009-182235. However, even if the warpage of the wafer during cooling can be suppressed, the wafer during cooling shrinks. For this reason, when it shrinks, the back surface of a wafer rubs with a cooling plate and a wafer support pin, and generate | occur | produces micro scratches like micro scratches on the back surface of a wafer.

To date, minor scratches on the back of the wafer have not been a problem. However, with the miniaturization of semiconductor devices, it has been found that defocusing due to minute scratches generated on the back surface of the wafer occurs in the exposure step, and the yield is lowered. The minute scratches generated on the back surface of the wafer generate minute irregularities on the back surface of the wafer. When the film forming process is repeated on the wafer, the film forming gas flows into the back surface and film formation is performed. Therefore, a thin film gradually accumulates on the convex portion, and the convex portion becomes large. The enlarged convex portion deteriorates the flatness of the surface of the wafer loaded on the exposure stage.

The minute scratches generated on the back surface can be removed by performing the back surface polishing of the wafer. In addition, growth of a convex part can be suppressed when back surface cleaning of a wafer is performed. However, when the back polishing or the back cleaning is not performed or if the back polishing or the back cleaning cannot be put in the process, the wafer is left with a small scratch on the back surface, and the film forming step is performed with the grown convex portion. Or an exposure process.

This invention is made | formed in view of the said situation, and provides the cooling method of a to-be-processed object, a cooling apparatus, and a computer-readable storage medium which can suppress the generation | occurrence | production of the damage to the back surface of a to-be-processed object.

The cooling method of the to-be-processed object which concerns on the 1st aspect of this invention is a cooling method of the to-be-processed object which cools the heated to-be-processed object using the cooling member which has a cooling mechanism, (1) The said to-be-processed object is On the object support pin which supports a to-be-processed object, it loads under the pressure of a vacuum process, and supplies the cooling gas which cools the to-be-processed object at a 1st flow volume in the state which separated the to-be-processed object from the said cooling member, and the said feature Raising the pressure around the liquid body to a first pressure higher than the pressure of the vacuum treatment for cooling the object to be treated for a first time; and (2) lowering the object support pin to lower the object to be treated by the cooling member. In the state of being stacked or in proximity to the bed, the cooling gas is supplied at a second flow rate greater than the first flow rate, so that the pressure around the target object is greater than the first pressure. It raises to a high 2nd pressure, and the process of cooling said to-be-processed object for a 2nd time further is provided.

The cooling apparatus which concerns on the 2nd aspect of this invention is the container comprised so that internal pressure can be changed between the pressure of a vacuum process, and atmospheric pressure, the cooling gas supply mechanism which supplies a cooling gas in the said container, and the inside of the said container. A cooling member having an exhaust mechanism for exhausting, a cooling mechanism provided in the container to cool the target object by stacking or adjoining the target object, and protrudingly recessed with respect to the cooling member, The workpiece support pin which receives the object to be processed from the cooling member and descends in the state where the object is received, thereby placing or processing the object to the cooling member, and the object to be processed according to the first aspect. The cooling gas supply mechanism, the cooling mechanism and the object support pin are cooled so as to cool according to the cooling method of the workpiece. A control device for controlling is provided.

A computer-readable storage medium according to the third aspect of the present invention is a computer-readable storage medium storing a control program that operates on a computer and controls a cooling device, wherein the control program is, when executed, the first embodiment. The cooling device is controlled so that the cooling method of the object to be processed is performed.

BRIEF DESCRIPTION OF THE DRAWINGS The top view which shows schematically an example of the semiconductor manufacturing system which can apply the cooling method of the to-be-processed object which concerns on one Embodiment of this invention.
2 is a cross-sectional view illustrating an example of a load lock unit.
3A is a cross-sectional view showing an example of a cooling method of an object to be processed according to one embodiment.
3B is a cross-sectional view illustrating an example of a cooling method of an object to be processed according to one embodiment.
3C is a cross-sectional view illustrating an example of a cooling method of an object to be processed according to one embodiment.
4 is a time chart according to an example of a method for cooling a target object according to one embodiment.
5A is a cross-sectional view illustrating a state in which a semiconductor wafer is brought close to a mounting surface of a cooling plate.
5B is a cross-sectional view illustrating a state in which a semiconductor wafer is brought close to a mounting surface of a cooling plate.
6 is an enlarged cross-sectional view of a distal end of a contact portion;
FIG. 7 is a drawing substitute photograph showing a state of the back surface of the silicon wafer cooled by the cooling method of the object to be processed according to the embodiment after completion of cooling. FIG.
8 is a time chart according to a cooling method according to a comparative example.
9 is a drawing substitute photograph showing a state of the back surface of a silicon wafer cooled by a cooling method according to a comparative example after completion of cooling.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described with reference to drawings. In addition, a common reference numeral is attached | subjected to the part which is common throughout the figure.

1 is a plan view schematically showing an example of a semiconductor manufacturing system that can apply a method for cooling a target object according to an embodiment of the present invention. In Fig. 1, a multi-chamber type semiconductor manufacturing system having a load lock unit having a load lock chamber is shown.

As shown in FIG. 1, the semiconductor manufacturing system is provided with four vacuum processing units 1, 2, 3, and 4 which perform high temperature processes, such as a film-forming process, for example, and each of these vacuum processing units 1 4 to 4 are respectively provided corresponding to four sides of the transfer chamber 5 forming a hexagon. In addition, the load lock units 6 and 7 are provided in the other two sides of the conveyance chamber 5, respectively. Carry-in / out chamber 8 is provided in the opposite side to the conveyance chamber 5 of these load lock units 6 and 7, and the semiconductor wafer as a to-be-processed object on the opposite side to the load lock units 6 and 7 of the carry-out chamber 8 is shown. Ports 9, 10, and 11 are provided for installing three FOUPs (Front Opening Unified Pods). The vacuum processing units 1, 2, 3, and 4 are configured to perform a predetermined vacuum processing, for example, a film forming process or an etching process, in a state in which a target object is mounted on a processing plate.

The vacuum processing units 1-4 are connected to each side of the conveyance chamber 5 via the gate valve G, These are communicated with the conveyance chamber 5 by opening the corresponding gate valve G, and corresponding gate valve By closing G, it cuts off from the conveyance chamber 5. In addition, the load lock units 6 and 7 are connected to each of the remaining sides of the conveyance chamber 5 via the 1st gate valve G1, and also through the 2nd gate valve G2 to the carrying-out chamber 8 through. Is connected. The load lock chambers 6 and 7 communicate with the transfer chamber 5 by opening the first gate valve G1 and are disconnected from the transfer chamber by closing the first gate valve G1. In addition, the second gate valve G2 is opened to communicate with the carry-in / out chamber 8, and the second gate valve G2 is closed to shut off from the carry-in / out chamber 8.

In the conveyance chamber 5, the conveying apparatus 12 which carries out the carrying out of the semiconductor wafer W with respect to the vacuum processing units 1-4 and the load lock units 6 and 7 is provided. This conveying apparatus 12 is arrange | positioned in the substantially center of the conveyance chamber 5, and the two support arms 14a and 14b which support the semiconductor wafer W in the front-end | tip part of the rotation-expansion part 13 which can be rotated and expanded. These support arms 14a and 14b are provided in the rotation / expansion portion 13 so as to face in opposite directions to each other. The inside of this conveyance chamber 5 is hold | maintained by predetermined | prescribed vacuum degree.

Three ports 9, 10, and 11 for hoop F installation, which are wafer storage containers in the carrying in and out chamber 8, are provided with shutters (not shown), respectively, and the wafers W are accommodated in these ports 9, 10, and 11. Or the empty hoop F is installed directly, and when it is installed, the shutter is detached to communicate with the carry-in / out chamber 8 while preventing the intrusion of outside air. Moreover, the alignment chamber 15 is provided in the side surface of the carrying in / out chamber 8, and alignment of the semiconductor wafer W is performed there.

In the carry-in / out chamber 8, the conveying apparatus 16 which carries out the carrying-in of the semiconductor wafer W with respect to the hoop F, and the carrying out of the semiconductor wafer W with respect to the load lock units 6 and 7 is provided. This conveying apparatus 16 has a multi-joint arm structure, and is capable of traveling on the rail 18 along the arrangement direction of the hoop F, and loads the semiconductor wafer W on the hand 17 of the distal end portion thereof. The conveyance is performed.

This vacuum processing system has the process controller 20 which consists of a microprocessor (computer) which controls each structure part, and each structure part is connected to this process controller 20, and it is set as the structure controlled. In addition, the process controller 20 is connected to a user interface 21 including a keyboard on which an operator performs a command input operation or the like for managing the vacuum processing system, or a display for visualizing and displaying the operation status of the plasma processing apparatus. It is.

In addition, the process controller 20 includes a control program for realizing various processes executed in the vacuum processing system under the control of the process controller 20, and for executing the processes in each component of the vacuum processing system according to the processing conditions. A storage unit 22 is stored in which a program, for example, a film forming recipe for a film forming process, a conveying recipe for conveying a wafer, a purge recipe for adjusting pressure inside the load lock chamber, and the like are connected. These various recipes are stored in the storage medium in the storage unit 22. The storage medium may be fixed, such as a hard disk, or may be portable, such as a CD-ROM, a DVD, or a flash memory. In addition, a recipe may be appropriately transmitted from another apparatus via, for example, a dedicated line.

Then, if necessary, an arbitrary recipe is called from the storage unit 22 by the instruction from the user interface 21 and executed by the process controller 20, so that the vacuum processing system is controlled under the control of the process controller 20. The desired process of is performed. In addition, the process controller 20 is capable of controlling the pressure and the height of the wafer W so as to suppress deformation of the wafer while the load lock units 6 and 7 are processing based on the standard purge recipe. It is.

2 is a cross-sectional view showing an example of the load lock unit 6 (7).

As shown in FIG. 2, the load lock unit 6 and 7 have the container 31 comprised so that an internal pressure can be changed between the pressure of a vacuum process, and atmospheric pressure, and the inside of the container 31 is a semiconductor. The cooling member which has a cooling mechanism which cools the semiconductor wafer W by loading or adjoining the wafer W is provided. In this example, the cooling member is used as the cooling plate 32, and this cooling plate 32 is installed in the container 31 in the state supported by the leg part 33. As shown in FIG.

One side wall of the container 31 is provided with an opening 34 in communication with the transfer chamber 5 held in vacuum, and an opening 35 in communication with the carry-out chamber 8 held at atmospheric pressure in the side wall opposite thereto. ) Is formed. The opening 34 is openable by the first gate valve G1, and the opening 35 is openable by the second gate valve G2.

At the bottom of the container 31, an exhaust port 36 for evacuating the inside of the container 31 and a cooling gas inlet 37 for introducing a cooling gas into the container 31 are provided. An exhaust pipe 41 is connected to the exhaust port 36, and the exhaust pipe 41 is provided with an on-off valve 42, an exhaust speed adjusting valve 43, and a vacuum pump 44. In addition, a cooling gas introduction pipe 45 for introducing a cooling gas into the container 31 is connected to the cooling gas introduction port 37, and the cooling gas introduction pipe 45 extends from the cooling gas source 48. In the meantime, the shut-off valve 46 and the flow regulating valve 47 are provided.

When conveying the wafer W between the conveyance chamber 5 on the vacuum side, the on-off valve 46 is closed and the on-off valve 42 is opened. In this state, the exhaust speed adjusting valve 43 is adjusted to exhaust the inside of the container 31 through the exhaust pipe 36 by the vacuum pump 44 at a predetermined speed, and the pressure in the container 31 is transferred to the transfer chamber ( 5) The pressure corresponding to the pressure inside is set. When the pressure in the container 31 becomes a pressure corresponding to the pressure in the transfer chamber 5, the first gate valve G1 is opened to communicate between the container 31 and the transfer chamber 5. In addition, when conveying the wafer W between the carrying-in / out chamber 8 of the atmospheric side, the switching valve 42 is closed and the switching valve 46 is opened. In this state, the flow control valve 47 is adjusted to introduce the cooling gas into the container 31 from the cooling gas source 48 via the cooling gas introduction pipe 45. In addition, an example of the introduction method of a cooling gas is mentioned later. When the pressure in the container 31 becomes atmospheric pressure or a pressure corresponding to the vicinity of the atmospheric pressure, the second gate valve G2 is opened to communicate between the container 31 and the loading / unloading chamber 8.

The on-off valve 42, the exhaust speed regulating valve 43, the flow regulating valve 47, and the on / off valve 46 are controlled by the valve control mechanism 49. By controlling these valves, the inside of the container 31 is changed between atmospheric pressure and vacuum. In addition, the valve control mechanism 49 is controlled based on the command from the process controller 20.

In the cooling plate 32, a plurality of wafer support pins 50 for wafer transfer, for example, nine (only two are shown) are provided so as to protrude and dent against the surface of the cooling plate 32. The pin 50 is fixed to the support plate 51. And the wafer support pin 50 is elevated via the support plate 51 by elevating the rod 52 by the drive mechanism 53, such as a motor which can adjust a raise position. Reference numeral 54 is a bellows.

In the cooling plate 32, a cooling medium flow path 55 is formed as a cooling mechanism, and a cooling medium introduction pipe 56 and a cooling medium discharge pipe 57 are connected to the cooling medium flow path 55. The cooling medium, such as cooling water, flows through the non-cooling medium supply part, and the wafer W loaded can be cooled.

The process controller 20 also controls the load lock units 6 and 7, controls the valve control mechanism 49 and the drive mechanism 53 in accordance with the process recipe, so that the pressure in the container 31 and the wafer W are controlled. The height position of the is controlled.

Next, the cooling method of the to-be-processed object which concerns on one Embodiment of this invention is demonstrated.

3A to 3C are cross-sectional views showing an example of a cooling method of an object according to an embodiment of the present invention, and FIG. 4 is a time chart according to an example of a cooling method of an object according to an embodiment of the present invention. . 3A-3C, illustration is abbreviate | omitted about the container 31, gate valve G1, G2, etc. In addition, in FIG.

First, as shown in FIG. 3A and FIG. 4, the pressure in the container 31 is made into the pressure corresponding to the pressure in the conveyance chamber 5. As shown in FIG. In this example, the pressure used when the vacuum processing units 1 to 4 are processed varies depending on the process, but the pressure in the conveying chamber 5 is almost constant, for example, several Torr, which is referred to herein as a vacuum treatment. It is called the pressure of. In addition, the wafer support pin 50 is raised to protrude from the mounting surface 32a of the cooling plate 32.

Subsequently, as shown in FIG. 3B and FIG. 4, the gate valve G1 is opened to be processed from the transfer chamber 5 in any one of the vacuum processing units 1 to 4, for example, 300 ° C. to 500 ° C. FIG. The semiconductor wafer W heated to such an extent is carried in the container 31, and is mounted on the wafer support pin 50. Subsequently, with the gate valve G1 closed and the semiconductor wafer W spaced apart from the mounting surface 32a of the cooling plate 32, the cooling gas is slowly introduced into the container 31 for about 5 seconds at a flow rate of, for example, 3000 sccm. By supplying, the pressure in the container 31, that is, the pressure around the semiconductor wafer W is slightly raised to a pressure of 50 Torr (6650 Pa) or less beyond the pressure of the vacuum treatment (slow purge 1 in FIG. 4). In this example, the semiconductor wafer W was spaced apart from the mounting surface 32a so as not to lower the wafer support pin 50. The wafer support pin 50 was a state in which the semiconductor wafer W was received. The distance L1 between the semiconductor wafer W and the mounting surface 32a in this state is, for example, about 20 mm.

In addition, in this example, the wafer support pin 50 stops supplying the cooling gas as it has received the semiconductor wafer W (close the valve 46 in FIG. 4). In this state, it is maintained for about 5 seconds. In addition, the waiting process hold | maintained for about 5 second can be abbreviate | omitted according to the magnitude | size of the semiconductor wafer W, the temperature at which the semiconductor wafer W was heated, etc., for example.

In the process shown in FIG. 3B, a small amount of cooling gas is slowly supplied while the semiconductor wafer W is spaced apart from the mounting surface 32a. This causes a slow heat exchange between the semiconductor wafer W and the cooling gas for a few seconds from the start of cooling. Due to the slow heat exchange, the heated semiconductor wafer W is cooled slowly.

The semiconductor wafer W is shrunk by starting cooling. In this example, a small amount of cooling gas is slowly supplied at the start of cooling (time T1 in FIG. 4). Thereby, the shrinkage start speed of the semiconductor wafer W at the time of cooling start can be approached to zero limitlessly. By making the shrinkage start speed close to zero, the "friction" of the back surface of the semiconductor wafer W and the contact portion 50a of the wafer support pin 50 when the semiconductor wafer W starts to contract can be alleviated.

In addition, the semiconductor wafer W is not moved without lowering the wafer support pin 50 for several seconds from the start of cooling. For several seconds from the start of cooling, the temperature of the semiconductor wafer W is still high. It is thought that the high temperature semiconductor wafer W is more likely to be scratched than the low temperature semiconductor wafer W. For this reason, several seconds from the start of cooling, the wafer support pin 50 is not lowered and mechanical vibration is not imparted to the semiconductor wafer W. In addition, if the speed of pressure rise in the container 31 is too fast, the semiconductor wafer W held on the wafer support pin 50 may be displaced. Therefore, the pressure rise speed is equal to the pressure (for example, several Torr) of the vacuum treatment. The same degree is preferable, for example, 2 to 9 Torr / sec, more preferably 3 to 5 Torr / sec. Thereby, unnecessary "friction" of the back surface of the semiconductor wafer W and the contact part 50a can be suppressed for several seconds from a cooling start.

Next, as shown in FIGS. 3C and 4, when the temperature of the semiconductor wafer W drops to a certain degree, the wafer support pins 50 are lowered, and the semiconductor wafer W is placed on the mounting surface 32a of the cooling plate 32. It is made to be mounted on or in proximity.

In addition, the state which adjoins is that the semiconductor wafer W protrudes from the mounting surface 32a on the state closer to the mounting surface 32a than the state shown in FIG. 3B (refer FIG. 5A), or the mounting surface 32a. In addition, the fixed support pin 32b is provided, and the semiconductor wafer W is floated slightly from the mounting surface 32a (refer FIG. 5B). The distance L2 between the semiconductor wafer W and the mounting surface 32a when the semiconductor wafer W is slightly floated using the support pin 32b is, for example, about 0.5 mm. Subsequently, in a state where the semiconductor wafer W is loaded or approached on the mounting surface 32a of the cooling plate 32, cooling gas is supplied into the container 31, for example, at the same flow rate as that of the slow purge 1, 3000 sccm. The flow rate was slowly supplied for about 15 seconds to raise the pressure in the vessel 31 to a pressure of 100 Torr (13330 Pa) or less (slow purge 2 in FIG. 4). Next, the flow rate of the cooling gas is raised to a flow rate of 30000 sccm, for example, and supplied for about 20 seconds (main purge in FIG. 4). Thereby, the pressure in the container 31, ie, the pressure around the semiconductor wafer W, is raised to the atmospheric pressure or the pressure near the atmospheric pressure. In addition, the pressure near atmospheric pressure is the pressure of the range of +/- 5% with respect to atmospheric pressure, for example. As a result, the semiconductor wafer W is cooled to a temperature at which oxidation does not occur in the semiconductor wafer W by the cooling plate 32 and the cooling gas, or to a temperature at which the semiconductor wafer does not melt the resin wafer cassette made of resin, or room temperature. Is cooled.

In addition, in the example of the cooling method of the to-be-processed object which concerns on one Embodiment, the wafer support pin 50 is devised also. As described with reference to FIG. 3B, when cooling of the semiconductor wafer W is started, the semiconductor wafer W is shrunk. By contraction, the back surface of the semiconductor wafer W rubs against the contact portion 50a of the wafer support pin 50.

Therefore, in this example, the Vickers hardness of at least the object to be processed of the wafer support pin 50 and the contact portion 50a in contact with the semiconductor wafer W in this example is equal to or less than the Vickers hardness of the back surface of the semiconductor wafer W. Specifically, when the target object is a silicon wafer and the back surface is silicon, at least the material of the contact portion 50a of the wafer support pin 50 is made of quartz.

In this way, by making the material of the contact portion 50a at least quartz, the Vickers hardness of the contact portion 50a can be equal to or less than the Vickers hardness of the back surface of the silicon wafer. Thereby, the generation | occurrence | production of the damage by the friction of the back surface of a silicon wafer and the contact part 50a can further be suppressed.

In addition, in this example, the design was implemented also in the shape of the front-end | tip part of the contact part 50a. 6 is an enlarged cross-sectional view of the tip portion of the contact portion 50a.

As shown in FIG. 6, in this example, the shape of the front-end | tip part of the contact part 50a was made into the spherical surface. By making the shape of the tip portion of the contact portion 50a a spherical surface, scratches can be less likely to occur on the back surface of the semiconductor wafer W as compared with the case where the shape of the tip portion of the contact portion 50a is flat.

In addition, if the curved state of the spherical surface is severe, the tip end portion of the contact portion 50a becomes an acute angle, and scratches easily occur on the back surface of the semiconductor wafer W. Thus, in this example, the radius of curvature of the spherical surface was set to 5 mm. Thereby, generation | occurrence | production of the damage | wound to the back surface of the semiconductor wafer W can be suppressed more than the case where the curvature radius of a spherical surface is 2 mm, for example.

In addition, when the curved state of the spherical surface is gentle, the tip end portion of the contact portion 50a is brought close to the plane, and thus the back surface of the semiconductor wafer W is easily scratched. In this respect, the upper limit of the radius of curvature of the spherical surface may be about 10 mm.

In summary, the radius of curvature of the spherical surface of the tip portion of the contact portion 50a is preferably 5 mm or more and 10 mm or less.

The state of the back surface after completion | finish of cooling of the silicon wafer cooled according to the cooling method of the to-be-processed object which concerns on the said one Embodiment is shown in FIG.

As shown in FIG. 7, the state of the back surface of a silicon wafer is the grade which a contact mark is seen, and the minute scratches like micro scratches are not seen.

Moreover, as a comparative example, it cooled according to the time chart shown in FIG. 8, and made the material of the contact part of a wafer support pin into alumina (harder than Vickers hardness of the back surface of a silicon wafer), and made the shape of the front-end part of a contact part into a plane. The state of the back surface after completion of cooling in the case of FIG. 9 is shown.

As shown in FIG. 9, in the state of the back surface of the silicon wafer which is a comparative example, micro scratches like micro scratches are seen.

Thus, according to the cooling method of the to-be-processed object which concerns on the said one Embodiment, the heated semiconductor wafer W is mounted on the wafer support pin 50 under the pressure of a vacuum process, and the semiconductor wafer W is spaced apart from the cooling plate 32. The semiconductor wafer W is cooled slowly for several seconds from the start of cooling by supplying a cooling gas slowly in the made state. Thereby, abrupt shrinkage of the semiconductor wafer W at the time of cooling start of the semiconductor wafer W can be suppressed, and generation | occurrence | production of the damage to the back surface of the semiconductor wafer W can be suppressed.

In addition, during the process for a few seconds from the start of cooling, the wafer support pin 50 is not moved. By further including this configuration, it is possible to prevent the semiconductor wafer W from applying mechanical vibration to the semiconductor wafer W for a few seconds from the start of cooling, which is still at a high temperature. Thereby, generation | occurrence | production of the damage | wound to the back surface of the semiconductor wafer W can be suppressed in the period in which the semiconductor wafer W considered to be easy to generate | occur | produce a flaw is high temperature.

In addition, the material of the contact part 50a of the wafer support pin 50 shall be below the Vickers hardness of the back surface of the semiconductor wafer W. As shown in FIG. By further having this configuration, generation of scratches on the back surface of the semiconductor wafer W can be further suppressed.

In addition, the shape of the front-end | tip part of the contact part 50a is made into the spherical surface. By further having this configuration, generation of scratches on the back surface of the semiconductor wafer W can be suppressed better.

As mentioned above, according to one Embodiment of this invention, the cooling method of the to-be-processed object which can suppress the generation | occurrence | production of the damage to the back surface of a to-be-processed object, the cooling apparatus which can implement this cooling method, and a cooling apparatus are controlled by the said cooling method. A computer readable storage medium capable of doing so can be provided.

In addition, this invention is not limited to said one embodiment, A various deformation | transformation is possible. In addition, embodiment of this invention is not the only one said embodiment.

For example, in the said embodiment, although the vacuum processing system of the multi-chamber type which provided four vacuum processing units and two load lock units was demonstrated as an example, it is not limited to these numbers, The conveyance room is The load lock unit may be provided in the vacuum processing unit.

In addition, although the said one Embodiment prescribes processing time as shown in FIG. 4, it is not limited to the time shown in FIG. 4 also about processing time. If the process of following (1) and (2) is provided, processing time can be suitably changed and set according to the magnitude | size of a to-be-processed object and heating temperature.

(1) A heated gas is loaded on a workpiece support pin supporting the workpiece under a vacuum treatment pressure and the workpiece is cooled from the cooling member in a state where the workpiece is separated from the cooling member. Supplying at a flow rate and raising the pressure around the object to a first pressure higher than the pressure of the vacuum treatment to cool the object for a first time;

(2) The workpiece support pin is lowered, and the cooling gas is supplied at a second flow rate that is larger than the first flow rate in a state where the workpiece is loaded or approached on the cooling member, so that the pressure around the workpiece is first pressure. The process of raising the to-be-processed object for 2nd time more by raising it to higher 2nd pressure

In addition, this invention can be suitably modified in the range which does not deviate from the meaning.

Claims (12)

It is a cooling method of the to-be-processed object which cools the heated to-be-processed object using the cooling member which has a cooling mechanism,
(1) Cooling which cools the said to-be-processed object in the state which mounted the said to-be-processed object on the to-be-processed object support pin which supports this to-be-processed object, and separated the said to-be-processed object from the said cooling member. Supplying gas at a first flow rate, raising the pressure around the target object to a first pressure higher than the pressure of the vacuum treatment, and cooling the target object for a first time;
(2) The target object supporting pin is lowered, and the cooling gas is supplied at a second flow rate that is larger than the first flow rate in a state where the target object is placed or proximate to the cooling member, thereby surrounding the target object. And cooling the to-be-processed object for a second time by raising the pressure of the to a second pressure higher than said first pressure. The cooling method of the to-be-processed object of Claim 1 which does not move the to-be-processed object support pin during the process of said (1). The cooling method of the to-be-processed object of Claim 1 which makes the said 1st pressure exceeding the pressure of the said vacuum processing, and below 50 Torr, and making the said 2nd pressure into atmospheric pressure or the pressure of atmospheric pressure vicinity. The cooling method of the to-be-processed object of Claim 1 which makes the to-be-processed object support pin receive the to-be-processed object in the state which separated the said to-be-processed object from the said cooling member. The cooling method of the to-be-processed object of Claim 1 which makes the Vickers hardness of the contact part with the to-be-processed object of the said to-be-processed object support pin to be below the Vickers hardness of the back surface of the to-be-processed object. The cooling method of the to-be-processed object of Claim 5 whose material of the contact part with the to-be-processed object of the said to-be-processed object support pin is quartz, when the said to-be-processed object is a silicon wafer. The cooling method of the to-be-processed object of Claim 1 which makes the shape of the front-end | tip part of the contact part with a to-be-processed object of the said to-be-processed object support pin into a spherical surface, and sets the curvature radius of the said spherical surface to 5 mm or more and 10 mm or less. A container configured to be capable of varying the internal pressure between the vacuum pressure and the atmospheric pressure,
A cooling gas supply mechanism for supplying cooling gas into the container;
An exhaust mechanism for exhausting the inside of the container,
A cooling member provided in the container, the cooling member having a cooling mechanism that cools the object by stacking or proximity to the object;
It is provided so that it can protrude recessed with respect to the said cooling member, and receives the to-be-processed object from the state which protruded from the said cooling member, and lowers or injects the to-be-processed object to the said cooling member by descending in the state which received the to-be-processed object. Workpiece support pin,
The cooling apparatus provided with the control apparatus which controls the said cooling gas supply mechanism, the said cooling mechanism, and the said to-be-processed object support pin so that the said to-be-processed object may be cooled according to the cooling method of the to-be-processed object of Claim 1. The cooling apparatus of Claim 8 whose Vickers hardness of the contact part with the to-be-processed object of the said to-be-processed object support pin is below the Vickers hardness of the said to-be-processed object. The cooling apparatus of Claim 9 whose material of the contact part with the to-be-processed object of the to-be-processed object support pin is quartz, when the said to-be-processed object is a silicon wafer. The cooling apparatus of Claim 8 whose shape of the contact part of the to-be-processed object support pin with the to-be-processed object is spherical surface. A computer-readable storage medium storing a control program for operating on a computer and controlling a cooling device,
The control program, when executed, controls the cooling device such that the cooling method of the target object according to claim 1 is performed.

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