JP2012047120A - Cryopump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cryopump adsorbing gas such as hydrogen having lower condensing temperature having stable exhausting performance and exhausting speed for a long time and capable of miniaturizing the footprint.SOLUTION: The cryopump 1 has the cold storage type freezer 2 having the first, second cold heads 21, 22, the first, second cryopump sections 50 cooled by the first, second cold heads 21, 22, and the second cryopump sections 6, 7. The second cryopump sections 6, 7 have an the cryopanels 62 whose front surfaces 62f, 64f face to the baffle 5 and adsorption panells 63, the adsorption panells 63 are formed of the first areas 63a whose outer peripheral side is inclined, the second inclined areas 63b inside of the first the areas 63a, the third flat areas 63c inside of the second areas 63b, and the backsides 64g, the adsorbing material 65 is bonded to both surfaces 64f, 64g excepting the first areas 63a.

Description

  The present invention relates to a cryopump that captures gas molecules by adsorption and generates a high vacuum.

  As a conventional cryopump, as shown in FIG. 12, a cylindrical heat shield member 101 having an opening 102 at one end, a baffle 106 fixed to the heat shield member 101, and a heat shield member 101 are arranged. And a panel structure 110 that is cooled to a temperature lower than that of the heat shield member, and gas molecules that fly from the opening 102 to the inside of the heat shield member 101 in an adsorption region formed on the surface of the panel structure 110. The panel structure 110 includes first adsorption regions 112a, 113a, and 114a at portions where gas molecules can reach from the opening 102 via a linear flight path. The second adsorption regions 112b, 113b, 1 are formed at the site where the gas molecules do not reach from the opening 102 via the linear flight path. 4b is formed, and the exhaust velocity per unit area of the first adsorption regions 112a, 113a, 114a is relatively higher than the exhaust velocity per unit area of the second adsorption regions 112b, 113b, 114b. A pump 100 is disclosed.

  More specifically, the heat shield member 101 is fixed to the first cooling stage 104 of the refrigerator 103 such as a Gifford McMahon refrigerator installed in the main cryopump housing 109. A baffle 106 is provided on the opening 102 side of the heat shield member 101, and the internal space 108 of the vacuum chamber 120 and the internal space 107 of the heat shield member 101 communicate with each other through the baffle 106. The heat shield member 101 is cooled to about 80K to about 100K by refrigeration generated in the first cooling stage 104, and the baffle 106 is cooled to the same temperature as the first cooling stage 104 via the heat shield member 101. Is done.

  The panel structure 110 includes a panel mounting member 111, an uppermost panel 112, and lower panels 113 and 114, and is fixed to the second cooling stage 105 of the refrigerator 103 in the internal space 107. The panel structure 110 is cooled to the same temperature as that of the second cooling stage 105 by the refrigeration of about 10K to about 20K generated in the second cooling stage 105. In FIG. 12, each of the panels 112, 113, and 114 has a truncated cone side surface shape, and the diameter of the side surface nearer to the opening 102 side is smaller, but a flat plate shape parallel to the upper surface 111 a of the panel mounting member 111. But it ’s okay. Activated carbon 115 is adhered to the entire surface of each panel 112, 113, 114 on the opening 102 side (hereinafter referred to as the front surface) with an adhesive, and activated carbon 116 is adhered to the entire surface on the back side of the front surface (hereinafter referred to as the back surface). Has been. The diameter of the activated carbon 115 is smaller than the diameter of the activated carbon 116. First adsorption regions 112a, 113a, 114a are formed on the front side of each panel 112, 113, 114 to which the activated carbon 116 is bonded, and the back side of each panel 112, 113, 114 to which the activated carbon 116 is bonded is the second side. Adsorption regions 112b, 113b, and 114b are formed. The temperatures of the first suction regions 112a, 113a, and 114a and the second suction regions 112b, 113b, and 114b are cooled to a temperature that is substantially the same as the temperature of the panel structure 110 (approximately 10K to approximately 20K). Accordingly, the first adsorption regions 112a, 113a, and 114a have a relatively higher exhaust speed than the second adsorption regions 112b, 113b, and 114b, and the second adsorption regions 112b, 113b, and 114b are the first adsorption regions. The gas occlusion amount is relatively better than 112a, 113a, 114a.

  The baffle 106 and the heat shield member 101 cool gas molecules flying from the vacuum chamber 120 toward the inside of the cryopump 100, and gas molecules (for example, water vapor, resist, etc.) whose vapor pressure becomes sufficiently low at the cooling temperature. Capture (solidify) on the surface. Gas (for example, nitrogen, hydrogen, etc.) molecules whose vapor pressure does not become sufficiently low at the temperature of the baffle 106 and resist (organic gas) molecules not captured by the baffle 106 fly into the internal space 107 through the baffle 106. To do.

  Among the gas molecules that have come in, the resist and the gas such as nitrogen whose vapor pressure is sufficiently low at the cooling temperature of the panel structure 110 are the activated carbon 115 in the first adsorption regions 112a, 113a, 114a, and the second adsorption. Adsorbed to the activated carbons 116 in the regions 112b, 113b, and 114b or solidified on the surfaces of the activated carbons 115 and 116. Although the amount of adsorption and solidification of gas such as resist and nitrogen is small, gas such as resist and nitrogen is also captured on the surface of the panel mounting member 111.

  Among the gases flying into the internal space 107, the gas such as hydrogen whose vapor pressure is not low at the cooling temperature of the panel structure 110 is the activated carbon 115 of the first adsorption regions 112a, 113a, 114a and the second adsorption region 112b. , 113b, and 114b are adsorbed to each activated carbon 116. In this way, gas molecules in the internal space 108 of the vacuum chamber 120 are exhausted (see, for example, Patent Document 1).

  A cryopump 200 shown in FIG. 13 is disclosed as a conventional cryopump. The cryopump 200 includes a housing 201, a refrigerator 203 such as a two-stage Gifford McMahon refrigerator, a radiation shield 207, a first-stage pump surface (baffle) 208, and a second-stage cryopanel 210. The flange 202 of the housing 201 is connected to a vacuum chamber (not shown) provided with a gate valve (not shown).

  The low-temperature unit 204 of the refrigerator 203 includes a first stage heat sink 205 that generates refrigeration of approximately 77K and a second stage heat sink 206 that generates refrigeration of approximately 4K to 25K, and is provided in the housing 201. A radiation shield 207 is fixed to the first stage heat sink 205, and a first stage pump surface 208 is provided on the opening 209 side of the radiation shield 207. The radiation shield 207 and the first stage pump surface 208 are cooled to about 100K to about 80K by refrigeration of about 77K generated in the first stage heat sink 205. The second-stage heat sink 206 is fixed with a second-stage cryopanel 210, and the second-stage heat sink 206 and the second-stage cryopanel 210 are surrounded by the radiation shield 207 and the first-stage pump surface 208.

  The second-stage cryopanel 210 includes two cryopanels 211 and 212 made of disks, cryopanels 213 to 218 to which an adsorbent 221 is bonded, a spacer 219, and a rod 220. The second-stage cryopanel 210 is fixed to the inner peripheral surface side of each cryopanel with a rod 220 via a spacer 219. The cryopanels 213 to 218 have peripheral bent portions 213a to 218a formed by bending the outer peripheral end of a donut-shaped disk to the first stage pump surface 208 side by approximately 45 °, and the outermost portions of the cryopanels 213 to 218 are formed. The outer diameters of the ends 213d to 218d are sequentially increased in this order.

  Here, the surface on the first stage pump surface 208 side of the cryopanels 213 to 218 is the front surface, and the back surface of the front surface is the back surface. In the second stage cryopanel 210, an adsorbent 221 such as activated carbon or zeolite is bonded to the flat back surfaces 213b to 218b of the cryopanels 213 to 218 excluding the peripheral bent portions 213a to 218a and the contact surfaces of the spacers. . The adsorbent 221 is not bonded to the front surfaces 213c to 218c of the cryopanels 213 to 218, the peripheral bent portions 213a to 218a, and both surfaces of the cryopanels 211 and 212. The temperatures of the cryopanels 211 and 212, the cryopanels 213 to 218, and the adsorbent 221 are cooled to about 30K to about 10K by refrigeration of about 4K to 25K generated in the second stage heat sink 206. (For example, refer to Patent Document 2).

JP 2009-108744 A JP-T 63-501585

  However, according to Patent Document 1, activated carbon 115 is adhered to the first adsorption region 112a of the uppermost panel 112, and radiant heat is received from the baffle 106 side. Since activated carbon 115 has a higher emissivity than metal, a larger amount of radiant heat enters from the baffle 106 side than when the activated carbon 115 is not bonded to the front surface of the uppermost panel 112. The intrusion radiant heat raises the temperature of the panel structure 110, which causes a problem that the adsorption capacity (exhaust capacity) and the exhaust speed of the cryopump 100 decrease. Further, the exhaust capacity and exhaust speed of the continuous use for a long time rapidly increase. There is a problem of deterioration.

  Further, when the intervals between the panels 112, 113, and 114 are large, nitrogen or resist gas molecules that collide with the heat shield member or the like in the internal space 107 and fly back are first adsorbed on the lower panels 113 and 114. Adsorbed on the activated carbon 115 in the regions 113a and 114a or solidified on the surface of the activated carbon 115. For this reason, the activated carbon 115 in the first adsorption regions 113a and 114a of the lower panels 113 and 114 has a problem that the adsorption ability (exhaust ability) and the exhaust speed of a gas such as hydrogen are reduced. Furthermore, there arises a problem that the exhaust capacity and exhaust speed for a gas such as hydrogen in continuous use for a long time rapidly deteriorate.

  Further, when each of the panels 112, 113, and 114 is a flat plate parallel to the upper surface 111a of the panel mounting member 111, hydrogen or the like is used for the same reason as described above, regardless of the size of each interval between the panels 112, 113, and 114. For the other gases, there are the same problems as described above.

  In order to increase the adsorption capacity and exhaust speed of a gas such as hydrogen, the number of panels may be increased in order to increase the surface area of the activated carbon 115 without changing the spacing between the panels of the panel structure 110. However, an increase in the number of panels increases the size of the panel structure 110, resulting in an increase in the size of the cryopump 100 and an increase in occupied space installed in the vapor deposition apparatus.

  Furthermore, the uppermost panel 112 and the lower panels 113 and 114 have a substantially truncated cone shape and are not divided in the radial direction. For this reason, it is difficult for gas molecules to fly to the activated carbon 115 on the center side of the first adsorption regions 113a and 114a and the activated carbon 116 on the center side of the second adsorption regions 112b, 113b and 114b, and the exhaust of the cryopump 100 is exhausted. There is a problem that the speed decreases.

  According to Patent Document 2, water vapor having a high condensation temperature from the vacuum chamber or resist is caught by the first stage pump surface 208 and solidified. Gas molecules such as nitrogen having a relatively low condensation temperature and gas molecules of the resist not solidified on the first stage pump surface 208 pass through the first stage pump surface 208 and fly to the second stage cryopump 210, The cryopanels 211 and 212, the surfaces 213c to 218c of the cryopanels 213 to 218, the outermost ends 213d to 218d, and the peripheral bent portions 213a to 218a are solidified. Since the peripheral bent portions 213a to 218a are bent by approximately 45 ° toward the first-stage pump surface 208, the gas molecules such as nitrogen and the gas molecules of the resist are mostly on the back surfaces 213b to 218b of the cryopanels 213 to 218. It is not adsorbed by the adsorbent 221.

  Gas molecules such as hydrogen and helium having a very low condensation temperature pass through the first-stage pump surface 208 and are adsorbed by the adsorbent 221 on the back surfaces 213b to 218b of the cryopanels 213 to 218. However, when a large amount of gas molecules such as hydrogen and helium are generated in the vacuum chamber, the adsorbent 221 is bonded only to the back surfaces 213b to 218b of the cryopanels 213 to 218. For this reason, the cryopump 200 has a capacity shortage of the adsorbent 221 with respect to gas molecules such as hydrogen and helium, which causes a problem of a decrease in exhaust capacity and exhaust speed and a decrease in exhaust capacity and exhaust speed over a long period of time. .

  Further, in order to increase the capacity of the adsorbent 221, the exhaust speed, the exhaust capacity and exhaust speed over a long period of time for gas molecules such as hydrogen and helium, the surfaces 213 c to 218 c of the cryopanels 213 to 218 are also provided. It is conceivable to adhere the adsorbent 221. However, since the peripheral bent portions 213a to 218a are bent by approximately 45 ° in the direction of the first-stage pump surface 208, nitrogen or resist gas molecules flying between the cryopanels 213 to 218 are exposed to the surfaces 213c to 218c. Adsorbed on the side adsorbent 221 or solidified on the surface of the adsorbent 221 on the side of the surfaces 213c to 218c. For this reason, the adsorption capability with respect to gas, such as hydrogen or helium, of the adsorbent 221 by the side of the surface 213c-218c is insufficient. As a result, the cryopump 200 has a capacity shortage of the adsorbent 221 with respect to gas molecules such as hydrogen and helium, and causes a problem of a decrease in exhaust capacity and exhaust speed and a decrease in exhaust capacity and exhaust speed over a long period of time. .

  Further, when the number of cryopanels 213 to 218 is increased to increase the capacity of the adsorbent 221, the exhaust speed, and the exhaust speed of the exhaust capability over a long period of time for gas molecules such as hydrogen and helium, the second There is a problem that the stage cryopanel 210 is increased in size, and the housing 201 is increased in size, and the installation space of the cryopump 200 is increased.

  Further, the cryopanels 213 to 218 have a substantially truncated cone shape and are not divided in the radial direction. For this reason, the adsorbent 221 on the center side of the cryopanels 213 to 218 has a problem that gas such as hydrogen is difficult to fly and the exhaust speed of the cryopump 200 is reduced.

  The present invention has been made in view of the above problems, and is a cryopump that adsorbs a gas having a low condensation temperature, such as hydrogen, and has a stable pumping capacity and pumping speed over a long period of time. An object of the present invention is to provide a cryopump capable of miniaturizing the occupied space.

  In order to solve the above-mentioned problem, the invention described in claim 1 is a cold storage type refrigerator having a first cold head that generates refrigeration and a second cold head that generates refrigeration at a temperature lower than that of the first cold head. And a first cryopump section that houses the second cold head and includes an opening, and includes a radiation shield that is in thermal contact with the first cold head, and a baffle that is provided on the opening side and is in thermal contact with the radiation shield; Surrounding the cryopanel arranged on the baffle side and the adsorption panel arranged with a predetermined spacing with respect to the back side when the baffle side of the cryopanel is the front side, with a radiation shield and a baffle, A second cryopump section cooled by a second cold head, and at least a front surface of the cryopanel is provided with a metal surface or plating. The adsorber panel has the baffle side surface of the adsorption panel as the front surface, the back side of the front surface as the back surface, and at least a part of the outer edge side from the baffle. A first inclined portion that is inclined in a direction that moves away and expands outward, a central portion that is provided inside the first inclined portion, and is provided between the central portion and the first inclined portion, in the same direction as the first inclined portion. Formed by the inclined second inclined portion, and adhering material is not attached to the front surface of the first inclined portion, and the front surface of the central portion, the front surface of the second inclined portion, and the back surface of the adsorption panel. Is adsorbed.

  According to a second aspect of the present invention, the cryopanel is provided with an inclined portion that is inclined in a direction in which at least a part of the outer edge side extends away from the baffle.

  Moreover, invention of Claim 3 is formed by the adsorbent edge part affixed on the back surface outer edge side of the 1st inclination part of the adsorption panel near the cryopanel among adjacent adsorption panels. If the backside virtual outer surface that is orthogonal to the arrangement direction is inside the backside outer edge, the distance between adjacent adsorption panels is the front of the center of the adsorption panel on the far side from the cryopanel. The virtual outer surface on the front side that is formed by the adsorbent edge attached to the surface and is orthogonal to the arrangement direction is on the side of the adsorption panel near the cryopanel with respect to the outer edge of the rear surface, and the virtual outer surface on the back side is on the back surface When protruding from the outer edge side, the distance between adjacent adsorption panels is such that the front virtual outer surface is closer to the cryopanel on the back virtual outer surface as a reference. In the Yonpaneru side.

  In the invention according to claim 4, the interval between the cryopanel and the adsorption panel arranged next to the cryopanel is the adsorbent end attached to the front surface of the central portion of the adsorption panel. The virtual outer surface on the front side that is formed by the above and orthogonal to the arrangement direction is on the cryopanel side with reference to the outer edge of the back surface of the inclined portion of the cryopanel.

  In the invention according to claim 5, the outer edge of the inclined portion of the cryopanel is adsorbed by the second inclined portion of the adsorption panel disposed next to the cryopanel from the inner peripheral side edge of the opening of the radiation shield. Prevents gas molecules flying directly toward the material from hitting the adsorbent.

  In the invention according to claim 6, the outer edge of the first inclined portion of the adsorption panel closer to the cryopanel among the adjacent adsorption panels is from the inner peripheral side edge of the opening of the radiation shield. It prevents the gas molecules flying directly toward the adsorbent on the second inclined portion of the adsorption panel farther from the cryopanel from hitting the adsorbent.

  In the invention according to claim 7, a plurality of the second cryopump units are provided with a predetermined gap in a direction orthogonal to the arrangement direction.

  In the first aspect of the present invention, at least the front surface of the cryopanel is a metal surface or a plated surface, and no adsorbent is attached. Thereby, the emissivity of the front surface of the cryopanel is lower than the emissivity of the adsorbent. Therefore, the radiation heat that goes straight from the baffle side and the opening side of the radiation shield to the cryopanel, or the radiation heat reflected and irradiated on the inner surface of the radiation shield is very small. In addition, since the adsorption panel is arranged on the back surface of the cryopanel, the adsorbent on the center portion of the adsorption panel and the second inclined surface is separated from the baffle side and the opening side of the radiation shield by the cryopanel. Much of the intrusion heat due to radiation is blocked. As a result, since the second cryopump unit is maintained at a low temperature (for example, approximately 25K to approximately 10K), the adsorption capacity of the adsorbent increases.

  Moreover, the adsorption panel is provided with the 1st inclination part and the 2nd inclination part, and the adsorbent is affixed on the front surface and back surface of an adsorption panel except the front surface of a 1st inclination part. Therefore, a sufficient capacity of the adsorbent can be secured. Furthermore, by optimizing the distance between adjacent adsorption panels, most of the gas molecules such as nitrogen and resist that fly from the gap outside the first inclined portion of the adsorption panel are in front of the first inclined portion. And the adsorbent on the front surface of the second inclined portion are solidified or adsorbed. Most of gases such as hydrogen are adsorbed by the adsorbent on the front surface of the center of the adsorption panel and the adsorbent on the back surface. As a result, the second cryopump unit can increase the adsorption capacity of the adsorbent with respect to a gas such as hydrogen having a very low condensation temperature and sufficiently ensure the capacity of the adsorbent. Moreover, the exhaust capability and exhaust speed with respect to gas molecules, such as nitrogen and a resist, are high.

  As described above, it is possible to provide a cryopump having a high exhaust capacity and an exhaust speed and a stable exhaust capacity and exhaust speed for a long time.

  Further, in the invention described in claim 2, the inclined portion provided in the cryopanel prevents the invasion of the radiant heat that goes straight from the baffle side and the opening side of the radiation shield to the adsorption panel adjacent to the cryopanel. The outer edge dimension of the cryopanel (the direction perpendicular to the arrangement of the adsorption panel) can be shortened. Therefore, the distance between the cryopanel and the adsorption panel and the distance between adjacent adsorption panels are made appropriate, and the number of adsorption panels is made appropriate, so that the second cryopump section can be made compact. Therefore, a cryopump with a small occupied space can be provided.

  In the invention according to claim 3, most of the gas molecules such as nitrogen and resist which come from the gap outside the first inclined portion of the adjacent adsorption panel are adsorbed on the side far from the cryopanel. It is solidified or adsorbed on the front surface of the first inclined portion of the panel and the adsorbent on the front surface of the second inclined portion. This allows only a small amount of nitrogen, resist, etc. to be adsorbed on the adsorbent on the back surface of the adsorption panel closer to the cryopanel and the adsorbent on the center front surface of the adsorption panel farther to the cryopanel. In many cases, gas molecules such as hydrogen are adsorbed. As a result, it is possible to provide a cryopump having a high exhaust capability (adsorption capability), exhaust capability and exhaust speed for gas molecules having a very low condensation temperature such as hydrogen and having a stable exhaust capability and exhaust speed for a long time.

  In the invention according to claim 4, most of gas molecules such as nitrogen and resist that come from the gap between the outside of the inclined portion of the cryopanel and the outside of the first inclined portion of the adjacent adsorption panel are cryogenic. It is solidified or adsorbed on the front surface of the first inclined portion and the adsorbent on the front surface of the second inclined portion of the adsorption panel adjacent to the panel. Thereby, the adsorbent on the front surface of the central portion of the adsorption panel mainly adsorbs gas molecules such as hydrogen. As a result, it is possible to provide a cryopump having a high exhaust capacity and exhaust speed for gas molecules having a very low condensation temperature such as hydrogen and having a stable exhaust capacity and exhaust speed for a long time.

  In the invention according to claim 5, the nitrogen or the like directly flying from the inner peripheral side edge of the opening of the radiation shield toward the adsorbent of the second inclined portion of the adsorption panel disposed next to the cryopanel Gas molecules such as resist are solidified by the cryopanel. As a result, it is possible to provide a cryopump having a high exhaust capacity and exhaust speed for gas molecules having a low condensation temperature such as hydrogen and having a stable exhaust capacity and exhaust speed for a long time.

  Further, in the invention described in claim 6, the radiation shield directly jumps from the inner peripheral side edge of the opening portion of the radiation shield toward the adsorbent on the front surface of the second inclined portion of the adsorption panel disposed after and after the cryopanel. Gas molecules such as nitrogen and resist are solidified mainly on the front surface of the first inclined portion. As a result, it is possible to provide a cryopump having an increased ability to adsorb gas such as hydrogen, a high exhaust capacity and exhaust speed for gas molecules having a low condensation temperature such as hydrogen, and a stable exhaust capacity and exhaust speed for a long time.

  In the invention according to claim 7, a plurality of the second cryopump units are provided with a predetermined gap in a direction orthogonal to the arrangement direction of the adsorption panels. Therefore, a gas having a very low condensing temperature such as hydrogen flying from the gap is adsorbed by the adsorbent of the adsorption panel at a short flying distance, so that the pumping speed of the cryopump is improved.

It is explanatory drawing of the cryopump which concerns on a present Example. It is A arrow directional view which shows the attachment to the radiation shield of the baffle in FIG. It is an A arrow directional view of the panel main body of the adsorption panel of FIG. It is CC sectional drawing of FIG. It is sectional drawing of the adsorption panel of FIG. It is sectional drawing of the cryopanel of FIG. It is a perspective view of the bracket of the 2nd cryopump part of FIG. It is a B arrow view of the 2nd cryopump part of FIG. It is D arrow line view of FIG. It is an enlarged view of the part of the 2nd cryopump part in EE sectional drawing of FIG. It is the elements on larger scale of another example of the 2nd cryopump part in EE sectional drawing of FIG. It is explanatory drawing of the cryopump of the prior art which concerns on a present Example. It is explanatory drawing of the other cryopump of the prior art which concerns on a present Example.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is an explanatory diagram of a cryopump according to the present embodiment. As shown in FIG. 1, the cryopump 1 includes a regenerative refrigerator 2 such as a Gifford McMahon refrigerator, a vacuum case 3, a first cryopump 50, and a second cryopump provided inside the radiation shield 4. Parts 6 and 7 (FIG. 8). The vacuum case 3 has a substantially cup shape, a bottomed cylindrical portion 31, a flange portion 32 provided in the opening 34 at the upper end of the cylindrical portion 31, and a refrigerator mounting port provided on the circumferential surface of the cylindrical portion 31. 33. The flange portion 32 is hermetically connected to a vacuum chamber 35 such as a semiconductor manufacturing apparatus, and the vacuum chamber 35 is provided with a gate valve (not shown) that controls connection and disconnection with the opening 34.

  The cold storage type refrigerator 2 includes, for example, a first cold head 21 that generates refrigeration of about 50K and a second cold head 22 that generates refrigeration of about 10K, for example, and a gas supply port 24 of the cold storage type refrigerator 2 The gas return port 25 is connected to a compressor (not shown) via a pipe (not shown). The room temperature side of the cylinder 23 forming the first cold head 21 is airtightly connected to the refrigerator mounting port 33 of the vacuum case 3.

  The radiation shield 4 is made of a plate material having good heat conduction such as aluminum, has a substantially cup shape, and the first cold head 21 is fixed to a flat portion 44 provided on a part of a cylindrical surface. Thereby, the radiation shield 4 is cooled to about 100K to about 50K by the freezing of about 50K generated in the first cold head 21. An opening 41 of the radiation shield 4 is provided on the opening 34 side of the vacuum case 3. On the inner peripheral surface of the radiation shield 4 on the opening 41 side, four stays 42 for fixing the baffle 5 are fixed equally.

  FIG. 2 is a view taken in the direction of arrow A showing the attachment of the baffle 5 to the radiation shield 4 in FIG. As shown in FIGS. 1 and 2, the baffle 5 includes a cage 55 having a substantially cross shape, and baffle members 51 to 54 whose outer peripheral surfaces have a truncated cone shape. The cage 55 and the baffle members 51 to 54 are formed of copper or the like having good heat conduction. The baffle members 51 to 53 are arranged such that the baffle members 51 are sequentially concentrically arranged on the center side with the center crossing position of the retainer 55 as the center, and end portions on the large diameter side of the baffle members 51, 52, and 53. These four locations are fixed to the cage 55 by welding or the like. The baffle member 54 is provided with slits 54a (FIG. 2) at four positions on the large-diameter end, and a holder 55 is inserted into the slit 54a so as to be concentric with the baffle member 53 and fixed by welding or the like. The The baffle 5 has a nickel-plated surface in order to suppress the intrusion of radiant heat, and the outside of the retainer 55 so that the small diameter side ends of the baffle members 51 to 54 face the opening 41 side of the radiation shield 4. The stay 56 is fixed to the stay 42 by a bolt 56 inserted into the mounting portion 55 a and a nut 57 on the stay 42 side of the radiation shield 4.

  The radiation shield 4 absorbs radiant heat from the vacuum case 3 and functions as a conductive member that cools the baffle 5 to about 100K to about 50K by refrigeration generated by the first cold head 21. Thereby, the baffle members 51-54 are cooled by about 100K to about 50K. The baffle 5 and the radiation shield 4 form a first cryopump unit 50 that solidifies water vapor or resist in the vacuum chamber 35.

  As shown in FIG. 1, the second cryopump unit 6 includes a bracket 61, a cryopanel 62, and a plurality of adsorption panels 63.

  FIG. 3 is a plan view of the panel main body 64 of the adsorption panel 63 as viewed from the direction A (FIG. 1), and FIG. 4 is a CC cross-sectional view of FIG. As shown in FIG. 3 and FIG. 4, the shape of the panel main body 64 viewed from the A direction is a substantially half-moon shape in which both ends of an arc having a circumferential angle smaller than 180 ° are connected by strings, and heat conduction such as copper is performed. Molded from a good plate. Here, the surface on the baffle 5 side of the panel main body 64 and the adsorption panel 63 is a front surface 64 f, and the rear surface of the front surface 64 f is a back surface 64 g of the panel main body 64 and the adsorption panel 63.

  The panel main body 64 includes a flat half-moon shaped central portion 64a, a second inclined portion 64b obtained by bending the arc-side edge portion of the central portion 64a, and a first inclined portion 64d provided outside the second inclined portion 64b. The flat band portion 64c connecting the second inclined portion 64b and the first inclined portion 64d, and the attachment portion 64e obtained by bending the chord side center portion of the panel main body 64 by 90 ° toward the back surface 64g. The second inclined portion 64b and the first inclined portion 64d are each bent toward the back surface 64g (FIG. 4). The bending angle α at which the second inclined portion 64b is bent from the central portion 64a is set to 135 ° to 165 °. The bending angle β at which the first inclined portion 64d is bent from the band portion 64c is set to 135 ° to 165 °. The belt portion 64c is substantially parallel to the central portion 64a.

  FIG. 5 is a cross-sectional view of the adsorption panel 63. As shown in FIG. 5, the adsorption panel 63 includes a back surface 64g of the panel body 64, a second inclined portion 64b on the front surface 64f side of the panel body 64, and a flat central portion 64a on the front surface 64f side of the panel body 64. An adsorbent 65 such as activated carbon is bonded to the top. Thereby, the front surface 64f side of the adsorption panel 63 is adsorbed to the first region 63a where the adsorbent 65 of the first inclined portion 64d and the band portion 64c is not bonded, and to the second inclined portion 64b of the panel body 64. A second region 63b to which 65 is bonded and a third region 63c to which the adsorbent 65 is bonded to the central portion 64a are formed.

  6 is a cross-sectional view of the cryopanel of FIG. Similarly to the panel body 64, the surface on the baffle 5 side of the cryopanel 62 is the front surface 62f, and the back surface of the front surface 62f is the back surface 62g. In FIG. 6, the cryopanel 62 is made of the same material as the panel main body 64 and has the same shape and the same dimensions. That is, the center part 62a, the 2nd inclination part (inclination part) 62b, the belt | band | zone part 62c, the 1st inclination part (inclination part) 62d, and the attaching part 62e are provided. The adsorbent is not bonded to at least the front surface 62f. The adsorbent is not bonded to the back surface 62g either, but in some cases, the adsorbent may be bonded.

Further, the front surface 62f of the cryopanel 62 is subjected to surface treatment such as nickel plating in order to make it difficult to receive radiant heat. In addition, if the material of the cryopanel 62 is a metal with low emissivity, the surface treatment such as plating may be performed without changing the surface of the metal, and the cryopanel 62 may be a plate material made of the same material as the panel main body 64. It does not need to be formed in the same shape and the same size. For example, the second inclined portion 62b, the belt portion 624c, and the first inclined portion 62d may be omitted, and a substantially half-moon shaped flat plate may be used. In this case, the dimensions of the substantially half-moon shaped cryopanel are the first region 63a, the second region 63b, and the third region of the adsorption panel 63 adjacent to the cryopanel 62 from the opening 41 of the baffle 5 and the radiation shield 4. The dimension which prevents the radiant heat which penetrate | invades directly into 63c is preferable.

  FIG. 7 is a perspective view of the bracket 61 of FIG. As shown in FIG. 7, the bracket 61 is formed of a plate material having good heat conduction such as copper, and a panel fixing portion 61a of an elongated plate portion and a head connecting portion 61b obtained by bending a central edge portion of the panel fixing portion 61a by 90 °. And formed from.

  8 is a B arrow view of the second cryopump parts 6 and 7 attached to the second cold head 22 in FIG. 1, and FIG. 9 is a D arrow view of FIG. 10 and 11 are partial enlarged views of the EE cross section of the second cryopump unit 6 in FIG. 9. 10 and FIG. 11 are different from each other in the bonding position of the adsorbent 65 on the back end portion of the first inclined portion 64d of the panel main body 64. FIG.

  As shown in FIGS. 8 and 9, the second cryopump unit 6 includes the cryopanel 62 facing the baffle 5 (FIG. 1) and the cryopanel 62 and a plurality of adsorptions sequentially from the upper side of FIG. 8. The panel 63 is fixed to the panel fixing portion 61a (FIG. 7) with a plurality of rivets 66 at a predetermined interval. Similar to the second cryopump unit 6, the second cryopump unit 7 includes a bracket 71, a cryopanel 62, and a plurality of adsorption panels 63. The bracket 71 is formed of a plate material having good heat conduction, such as copper, like the bracket 61, and the shape and dimensions of the bracket 61 are relative to the central axis X (FIG. 9) of the second cold head 22 of the regenerative refrigerator 2. Become symmetric.

  As shown in FIG. 10, the bent outer edge 62da of the cryopanel 62 of the second cryopump unit 6 and the edge of the first inclined portion 64d of each panel body 64 of the adsorption panel 63 are connected to the baffle 5. It is arranged in a direction away from you. The cryopanel 62 of the second cryopump unit 7 and the panel bodies 64 of the adsorption panel 63 are also arranged in the same direction. As shown in FIG. 9, the second cryopump parts 6 and 7 have a plurality of bolts in which the head connecting parts 61b and 71b of the brackets 61 and 71 are symmetrical with respect to the central axis X with a gap M therebetween. It is fixed to the second cold head 22 by 67. Therefore, the cryopanels 62 of the second cryopumps 6 and 7 and the panel main body 64 and the adsorbent 65 of each adsorption panel 63 are generated by the second cold head 22 via the brackets 61 and 71. It is cooled to about 25K to 10K by freezing at 10K.

  Next, the dimension setting of the 2nd cryopump parts 6 and 7 is demonstrated.

(Setting of the distance H1 between the cryopanel 62 and the adjacent adsorption panel 63)
The distance H1 in the D direction (FIGS. 8 and 10) between the cryopanel 62 of the second cryopump unit 6 and the adsorption panel 63 adjacent to the cryopanel 62 is the adsorbent 65 in the third region 63c. The front virtual outer surface 65a (FIGS. 5 and 10) formed by the above-mentioned is located at the same height as the rear outer edge 62db of the outer edge 62da of the cryopanel 62 or slightly on the rear surface 62g side (baffle 5 side) from the rear surface outer edge 62db. Set to For example, the front-side virtual outer surface 65a is set so as to be between the same height position as the rear-surface outer edge 62db and a position on the rear-surface 62g side by a distance of 36% of the layer thickness of the adsorbent 65 from the rear-surface outer edge 62db. Preferably, the front side virtual outer surface 65a is set so as to be between the same height position as the rear surface outer edge 62db and a position on the rear surface 62g side by a distance of 21% of the layer thickness of the adsorbent 65 from the rear surface outer edge 62db. . The layer thickness of the adsorbent 65 is exemplified as 1.4 mm. That is, the gas molecules of the molecular flow flying from between the outer edge 62da of the cryopanel 62 and the outer edge 64da of the panel body 64 adjacent to the cryopanel 62 (hereinafter referred to as arc-side gap R1 (FIGS. 9 and 10)) The distance H1 is set so that it does not directly hit the front-side virtual outer surface 65a of the adsorbent 65 in the third region 63c without being reflected. Preferably, the distance H1 is such that the front surface 64af of the central portion 64a of the lower panel body 64 in FIG. 10 is at the same height as the back surface outer edge 62db of the outer edge 62da of the upper cryopanel 62 in FIG. In FIG. 10, the distance H1 is such that the front-side virtual outer surface 65a of the adsorbent 65 in the third region 63c and the rear surface outer edge 62db of the outer edge 62da of the cryopanel 62 are at the same height.

(Setting of distance H2 between adjacent adsorption panels 63 and 63)
The adsorbent 65 on the back surface of the first inclined portion 64d of the panel main body 64 includes (1) adhesion that slightly protrudes the edge of the back surface outer edge 64db of the first inclined portion 64d, and (2) the back surface outer edge 64db. There are an adhesion slightly inside the ridge line and (3) an adhesion that matches the ridge line of the back surface outer edge 64db.

  In any of the above cases (1) to (3), the distance H2 in the D direction between the adjacent adsorption panels 63 and 63 is the same as that of the lower adsorption panel 63 in FIGS. The front-side virtual outer surface 65a (FIGS. 10 and 11) formed by the adsorbent 65 in the three regions 63c is at the same height as the rear-surface outer edge 64db of the first inclined portion 64d of the upper panel body 64, or , It is set so that it is on the side of the adsorption panel 63 slightly above the same height position. For example, the front-side virtual outer surface 65a is set so as to be between the same height position as the rear-surface outer edge 64db and the position on the adsorption panel 63 side by a distance of 36% of the layer thickness of the adsorbent 65 from the rear-surface outer edge 64db. Is done. Preferably, the front-side virtual outer surface 65a is located between the same height position as the rear-surface outer edge 64db and the position on the adsorption panel 63 side by a distance of 21% of the layer thickness of the adsorbent 65 from the rear-surface outer edge 64db. Is set. The layer thickness of the adsorbent 65 is exemplified as 1.4 mm. Thereby, between the outer edge 64da of the first inclined portion of the panel body 64 on the upper side (FIGS. 10 and 11) and the outer edge 64da of the first inclined portion of the panel body 64 on the lower side (FIGS. 10 and 11) ( Hereinafter, the gas molecules of the molecular flow coming from the arc-side gap R2 (FIGS. 9, 10, and 11) are blocked by the first region 63a and the second region 63 of the lower adsorption panel 63 and reflected. Without directly hitting the front-side virtual outer surface 65a of the adsorbent 65 in the third region 63c of the lower adsorption panel 63.

  Only in the case of the above-mentioned (1) bonding to be protruded (FIG. 10), the distance H2 is the front-side virtual formed by the end of the adsorbent 65 in the third region 63c of the lower adsorption panel 63 in FIG. The outer surface 65a (FIG. 10) is adhered to the back surface of the first inclined portion 64d of the upper panel body 64 in FIG. 10, and the rear surface side virtual outer surface 65b (FIG. 10) formed by the adsorbent 65 protruding from the back surface outer edge 64db. It may be set so as to be on the side of the adsorption panel 63 slightly above the same height position. Also in this case, the gas molecules of the molecular flow flying from the arc-side gap R2 are directly reflected without reflecting, and the virtual outer surface on the front side of the adsorbent 65 in the third region 63c of the lower adsorption panel 63 (FIG. 10). Does not hit 65a.

  In FIG. 10, the front-side virtual outer surface 65a of the adsorbent 65 of the adsorbent 65 in the third region 63c of the lower adsorption panel 63 is the rear outer edge 64db of the first inclined portion 64d of the upper panel body 64. It is in the same height position as the back side virtual outer surface 65b of the adsorbent 65 bonded to the back side.

  FIG. 11 shows the case of (3) adhesion to match the ridgeline of the back surface outer edge 64db, and the front-side virtual outer surface 65a of the adsorbent 65 of the adsorbent 65 in the third region 63c of the lower adsorption panel 63 is It matches the ridgeline of the outer edge 64db of the back surface of the lower panel body 64. The distance H2 in this case is as described above.

  Further, the distance H1 in the D direction (FIG. 8) between the cryopanel 62 of the second cryopump unit 7 and the adsorption panel 63 adjacent to the cryopanel 62, and the adsorption panels 63 adjacent to each other. , 63 is also the same as the second cryopump section 6 in the D direction.

(Dimension setting of outer edge 62da of first inclined portion 62d of cryopanel 62)
The outer edge 62da of the first inclined portion 62d of the cryopanel 62 has an adsorbent 65 of the second region 63b of the adsorption panel 63 disposed next to the cryopanel 62 from the inner peripheral side edge of the opening 41 of the radiation shield 4. It is set so as to prevent the gas molecules flying directly toward the surface from hitting the adsorbent 65 in the second region 63b.

(Dimension setting of outer edge 64da of first inclined portion 64d of panel body 64)
The outer edge 64da of the first inclined portion 64d of the panel main body 64 has a second region 64b of the panel main body 64 far from the cryopanel 62 of the panel main body 64 adjacent to the inner peripheral side edge of the opening 41 of the radiation shield 4. It is set so as to prevent gas molecules directly flying toward the adsorbent 65 from hitting the adsorbent 65 in the second region 64b.

  Next, the operation and effect of the cryopump according to the embodiment of the present invention will be described.

  After roughing the vacuum chamber 35 with a rotary vacuum pump (not shown), molecules such as water vapor, resist (organic material), nitrogen, oxygen, hydrogen, and helium still remain in the vacuum chamber 35. When the gate valve (not shown) installed in the vacuum chamber 35 is opened, these molecules fly to the opening 41 side of the radiation shield 4 and the baffle 5. Since the baffle 5 and the radiation shield 4 are cooled to about 100K to about 50K, water vapor and resist having a high condensation temperature are solidified on the surface of the baffle 5 and the outer peripheral surface of the radiation shield 4. Gas molecules (nitrogen, oxygen) having a relatively low condensation temperature and gas molecules (hydrogen, helium, etc.) having a very low condensation temperature are not solidified by the radiation shield 4 and the baffle 5. To the second cryopump region 8 (FIG. 1) surrounded by. Further, the resist that has not been solidified by the radiation shield 4 by the baffle 5 also passes through the opening portion 43 (FIGS. 1 and 2) on the inner peripheral surface side of the opening 41 of the baffle 5 or the radiation shield 4 and passes through the second cryostat. Fly to the pump area 8.

Incidentally, the cryopanel 62 receives heat radiation from the baffle 5 side and the opening 41 side of the radiation shield 4. Since the front surface 62f of the cryopanel 62 is plated with nickel having a low emissivity, the radiant heat received by the cryopanel 62 is very small. An adsorbent 65 is provided in the second region 63b and the third region 63c of the adsorption panel 63,
In general, the adsorbent 65 has a higher emissivity than metal. The adsorbents 65 in the second region 63 b and the third region 63 c of the adsorption panel 63 arranged next to the cryopanel 62 receive radiant heat directly entering from the baffle 5 and the opening 41 of the radiation shield 4 by the cryopanel 62. It is blocked.

  Further, by the respective dimension settings of the outer edge 62da of the first inclined portion 62d of the cryopanel 62 and the outer edge 64da of the first inclined portion 64d of the panel main body 64, the linear advance from the inner peripheral side of the opening 41 of the radiation shield 4 is achieved. The radiant heat is prevented from entering the second region 63 b of the adsorption panel 63 adjacent to the cryopanel 62. Therefore, the radiant heat entering the second cryopump parts 6 and 7 is very small.

  Thus, the second cryopump units 6 and 7 are cooled to a low temperature (approximately 25K to approximately 10K). As a result, the second cryopumps 6 and 7 have an increased capability of adsorbing gas molecules such as a resist having a high condensation temperature, gas molecules such as nitrogen having a relatively low condensation temperature, and hydrogen molecules having a very low condensation temperature.

  In addition, the second cryopump units 6 and 7 have adsorbents 65 bonded to both sides of the panel body 64 except for the first region 63a of the adsorption panel 63, and the number of adsorption panels 63 arranged is also appropriate. Secured. Accordingly, the capacity of the adsorbent capable of adsorbing gas molecules such as hydrogen having a very low condensation temperature, gas molecules such as nitrogen having a relatively low condensation temperature, and a resist having a high condensation temperature is ensured.

  By increasing the adsorption capacity of the adsorbent due to the temperature drop of the second cryopump sections 6 and 7 and securing the capacity of the adsorbent, the second cryopump sections 6 and 7 have a high exhaust capacity and exhaust speed. In addition, it has a stable exhaust capacity and exhaust speed over a long period of time.

  Most of the gas molecules such as the resist and nitrogen that have come to the second cryopump area 8 linearly fly to the front surface 62f of the cryopanel 62 and the first area 63a of the adsorption panel 63 without being reflected. It solidifies at a distance. In this case, the adsorption panel 63 is provided with a first region 63 a that is inclined so as to expand in a direction away from the baffle 5. Thereby, the resist flying from the arc-side gap R1 and the arc-side gap R2, gas molecules such as nitrogen, and the resist flying from the inner peripheral side edge of the opening 41 of the radiation shield 4 to the second region 63b of the adsorption panel 63. Gas molecules such as nitrogen are solidified mainly in the first region 63a. As described above, the second cryopumps 6 and 7 have a high exhaust speed with respect to gas molecules such as resist and nitrogen.

  Most of the remaining resist and gas molecules such as nitrogen are reflected on the inner surface of the radiation shield 4, the surface of the baffle 5, or the like, or are repeatedly reflected, while the back surface 62 g of the cryopanel 62 and the first of the adsorption panel 63. It solidifies in the region 63a. Most of the gas molecules such as the resist and nitrogen that could not be solidified in the first region 63 a of the adsorption panel 63 are adsorbent 65 in the second region 63 b of the adsorption panel 63 and the back surface 64 g of the adsorption panel 63. Is adsorbed on the adsorbent 65 or solidified on the adsorbent 65 surface. Therefore, the second cryopump units 6 and 7 have high exhaust capability (solidification capability and adsorption capability) for gas molecules such as resist and nitrogen. Also, the resist is solidified on the inner surface of the radiation shield 4.

  As described above, the second cryopump units 6 and 7 have high exhaust capacity and exhaust speed with respect to gas molecules such as resist and nitrogen, and have stable exhaust capacity and exhaust speed for a long time.

  The straight side edge 62h of the cryopanel 62 and the straight side edge 64h of the panel body 64 adjacent to the cryopanel 62 (hereinafter referred to as a straight side gap L1) and the adjacent panel bodies 64 and 64 Resist and gas molecules such as nitrogen hardly fly into the second cryopumps 6 and 7 from between the straight side edges 64h and 64h (hereinafter, the straight side gap L2).

  Gas molecules having a very low condensation temperature, such as hydrogen, that have come to the second cryopump region 8 are reflected directly or directly upon the inner surface of the radiation shield 4, the surface of the baffle 5, the front surface 62 f of the cryopanel 62, or the like. Are repeated to the arc side gap R1, the arc side gap R2, the straight side gap L1, and the straight side gap L2.

  Most of gas molecules such as hydrogen flying into the arc-side gap R1 are adsorbed by the adsorbent 65 in the second region 63b or reflected by the first region 63a, and further reflected by the back surface 62g of the cryopanel 62 and reflected by the first region 63a. It is adsorbed by the adsorbent 65 in the three regions 63c. Due to the setting of the distance H1, the resist and the gas molecules such as nitrogen flying into the arc-side gap R1 hardly fly into the third region 63c.

  Gas molecules such as hydrogen flying into the arc-side gap R2 are directly or reflected and are adsorbed by the adsorbents 65 in the second region 63b and the third region 63c of the adsorption panel 63, as shown in FIGS. Is adsorbed by the adsorbent 65 on the back surface 64g of the panel body 64 immediately above. By setting the distance H2 as described above, the resist and the gas molecules such as nitrogen flying into the arc-side gap R2 hardly fly into the third region 63c.

  Gas molecules such as hydrogen flying into the straight-side gap L1 are directly adsorbed by the adsorbent 65 in the second region 63b and the third region 63c of the adsorption panel 63, or the cryogenics immediately above in FIGS. The light is reflected by the rear surface 62g of the panel 62 and is adsorbed by the adsorbent 65 in the second region 63b or the third region 63c.

  Gas molecules such as hydrogen flying into the straight-side gap L2 directly adhere to the adsorbent 65 in the second region 63b and the third region 63c of the adsorption panel 63 and the panel body 64 immediately above in FIGS. It is adsorbed by the adsorbent 65 on the back surface 64g.

  By setting the distances H1 and H2, most of the gas molecules such as the resist and nitrogen flying from the arc-side gap R1 and the arc-side gap R3 are adhering to the first region 63a where the adsorbent of the adsorption panel 63 is not bonded. It is solidified. Further, the adsorption panel is formed from the inner peripheral edge of the opening 41 of the radiation shield 4 by setting each dimension of the outer edge 62da of the first inclined portion 62d of the cryopanel 62 and the outer edge 64da of the first inclined portion 64d of the panel body 64. Most of the gas molecules such as nitrogen and the resist that directly fly toward the adsorbent 65 in the second region 63b of 63 are solidified into the first region 63a where the adsorbent of the adsorption panel 63 is not bonded. Therefore, the adsorbent 65 of the adsorption panel 63 mainly adsorbs gas molecules such as hydrogen. As described above, the adsorbent 65 is bonded to the front surface 64f and the back surface 64g of the panel body 64 except for the first region 63a. Therefore, the second cryopump units 6 and 7 can sufficiently secure a capacity for adsorbing gas molecules having a very low condensation temperature such as hydrogen.

  As described above, the second cryopump units 6 and 7 have high exhaust capacity and exhaust speed for gas molecules having a very low condensation temperature such as hydrogen, and have stable exhaust capacity and exhaust speed for a long time.

  Further, the second cryopump units 6 and 7 are configured such that the adsorbent 65 is adhered to both surfaces 64f and 64g of the adsorption panel 63 except for the first region 63a, and the cryopanel 62 and an appropriate plurality of adsorptions. The panels 63 are arranged with a predetermined interval. Thereby, the second cryopump parts 6 and 7 can shorten the dimension of the panel body 64 in the arrangement direction while ensuring the capacity of the adsorbent 65 that provides a predetermined exhaust speed and a predetermined ultimate vacuum. Since the cryopanel 62 also includes the first inclined portion 62d and the first inclined portion 62b, the dimension in the direction orthogonal to the arrangement direction of the panel main bodies 64 can be shortened. As a result, the second cryopump units 6 and 7 are small in size, so that the space occupied by the cryopump 1 is reduced.

  Further, the second cryopump parts 6 and 7 are disposed across the second cold head 22, and a gap M (FIG. 8) is provided between the second cryopump parts 6 and 7. It may be substantially H2 (FIGS. 10 and 11). As a result, a gas having a very low condensing temperature, such as hydrogen, also flies from the straight side gap L1 and the straight side gap L2, and the adsorbent 65 on the back surface 64g of the adsorption panel 63 and the front surface at a short flying distance. It is adsorbed by the adsorbent 65 in the third region 63c on the 64f side. As a result, the exhaust speed of the cryopump 1 of the present invention is improved.

  In this embodiment, a gap M is provided between the cryopanel 62 of the second cryopump unit 6 and the cryopanel 62 of the second cryopump unit 7. When the radiant heat intrusion is reduced, the gap need not be provided.

1 Cryopump 1
2 Regenerative refrigerator 4 Radiation shield 5 Baffle 6, 7 Second cry pump part 21 First cold head 22 Second cold head 41 Opening part 50 First cry pump part 62 Cryo panel 62b Second inclined part (inclined part)
62d 1st inclination part (inclination part)
62da, 64da outer edge 62db, 64db back surface outer edge 62f, 64f, 64af front surface 62g, 64g back surface 63 adsorption panel 64a central part 64b second inclined part 64d first inclined part 65 adsorbent 65a front side virtual surface 65b back side virtual surface

Claims (7)

A regenerative refrigerator having a first cold head for generating refrigeration and a second cold head for generating refrigeration at a temperature lower than that of the first cold head;
A first cryopump unit that houses the second cold head and includes an opening, and includes a radiation shield that is in thermal contact with the first cold head, and a baffle that is provided on the opening side and is in thermal contact with the radiation shield. When,
The radiation shield, the baffle, and a cryopanel disposed on the baffle side, and an adsorption panel arranged at a predetermined interval with respect to a back surface when the baffle side of the cryopanel is a front surface And a second cryopump section that is cooled by the second cold head,
At least the front surface of the cryopanel is a metal surface or a plated surface, and an adsorbent is not attached,
The adsorption panel is inclined in a direction in which the baffle side surface of the adsorption panel is the front surface and the back side of the front surface is the back surface, and at least a part of the outer edge side is away from the baffle and extends outward. A first inclined portion, a central portion provided inside the first inclined portion, and a second inclined portion provided between the central portion and the first inclined portion and inclined in the same direction as the first inclined portion. And adhering material is not attached to the front surface of the first inclined portion, the front surface of the central portion, the front surface of the second inclined portion, and the back surface of the adsorption panel. Is a cryopump characterized by adsorbing material. 2. The cryopump according to claim 1, wherein the cryopanel is provided with an inclined portion that is inclined in a direction in which at least a part on an outer edge side moves away from the baffle and expands outward. 3. Of the adjacent adsorption panels, formed by the adsorbent end attached to the back outer edge side of the first inclined portion of the adsorption panel on the side close to the cryopanel and the arrangement direction When the back side virtual outer surface orthogonal to the inner side of the back side outer edge, the distance between the adjacent adsorption panels is the front surface of the central portion of the adsorption panel on the far side from the cryopanel. A front-side virtual outer surface that is formed by the adsorbent end adhered to and is orthogonal to the arrangement direction is on the side of the adsorption panel on the side close to the cryopanel with respect to the rear-surface outer edge,
When the back-side virtual outer surface protrudes from the back-side outer edge side, the spacing between adjacent adsorption panels is such that the front-side virtual outer surface is close to the cryopanel based on the back-side virtual outer surface The cryopump according to claim 1, wherein the cryopump is located on the side of the adsorption panel side. The space between the cryopanel and the adsorption panel arranged next to the cryopanel is formed by the adsorbent end portion adhered to the front surface of the central portion of the adsorption panel. 4. The cryopump according to claim 2, wherein the front-side virtual outer surface orthogonal to the arrangement direction is on the cryopanel side with reference to a rear-surface outer edge of the inclined portion of the cryopanel. An outer edge of the inclined portion of the cryopanel is directed from the inner peripheral side edge of the opening of the radiation shield to the adsorbent of the second inclined portion of the adsorption panel disposed adjacent to the cryopanel. The cryopump according to any one of claims 1 to 4, wherein gas molecules that directly fly are prevented from hitting the adsorbent. Among the adjacent adsorption panels, the outer edge of the first inclined portion of the adsorption panel closer to the cryopanel is connected to the cryopanel from the inner peripheral edge of the opening of the radiation shield. 6. The gas molecule that directly flies toward the adsorbent of the second inclined portion of the farther adsorption panel is prevented from hitting the adsorbent. 6. The cryopump described in the section. The cryopump according to any one of claims 1 to 6, wherein a plurality of the second cryopump units are provided with a predetermined gap in a direction orthogonal to the arrangement direction. pump.

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