CN112981349A

CN112981349A - Low-temperature deep hole bias sputtering device

Info

Publication number: CN112981349A
Application number: CN202110191654.7A
Authority: CN
Inventors: 张强; 夏久龙
Original assignee: Shanghai Yuejiang Industrial Co ltd
Current assignee: Shanghai Yuejiang Industrial Co ltd
Priority date: 2021-02-19
Filing date: 2021-02-19
Publication date: 2021-06-18
Anticipated expiration: 2041-02-19
Also published as: CN112981349B

Abstract

The invention relates to a low-temperature deep hole bias sputtering device, wherein a fixed cavity adapter is additionally arranged between a target material and a cavity, a cooling disc for placing a wafer is fixed on a wafer carrying platform, an upper shield and a lower shield are placed in the cavity adapter, the top of the upper shield is fixed on the cavity adapter, a plurality of through holes are formed in the wall of the lower part of the upper shield along the circumferential direction, a long strip adjusting hole corresponding to the through holes is formed in the wall of the lower shield along the circumferential direction, the lower part of the upper shield is sleeved in the lower shield, the corresponding long strip adjusting hole and the through holes are penetrated through by bolts to fix the upper shield and the lower shield, a bottom plate is fixed at the bottom of the lower shield, a central hole is formed in the bottom plate, a plurality of mounting holes are formed in the bottom plate along the circumferential direction, an insulating ceramic column is placed on the periphery of the edge, the bottom end of the T-shaped suspender is fixedly connected with the compression ring, and a plurality of adjustable compression bars are arranged on the compression ring along the circumferential direction.

Description

Low-temperature deep hole bias sputtering device

Technical Field

The invention relates to the technical field of semiconductors, is applied to a semiconductor metallization process, and particularly relates to a low-temperature deep-hole bias sputtering device.

Background

Magnetron sputtering is also known as physical vapor deposition at present and is a widely adopted method for depositing metal layers and non-metal materials in the manufacturing process of integrated circuits. The back hole processing method of the gallium nitride greatly reduces the interconnection time delay between chips and is a key technology for realizing three-dimensional integration.

In the traditional magnetron sputtering technology, metal atoms and ions are sputtered onto a wafer at a certain angle, but for a back hole of gallium nitride with a high depth-to-width ratio and a heterodromous structure, sputtered metal cannot effectively enter the inside of the hole, so that the film coverage rate at the bottom of the back hole is very low. The existing magnetron sputtering deep hole deposition technology is to load a negative bias on a wafer base of magnetron sputtering to attract plasma, and when the negative bias is in a proper range, more metal positive ions are attracted to the bottom of a deep hole. The bias of the susceptor is typically achieved by applying rf power to the wafer, since the wafer itself is insulated.

The application of bias sputtering in the back hole process is mainly to deposit an adhesion layer and a gold seed crystal layer inside the deep hole, wherein the adhesion layer has the function of enabling gold to be better adhered with other materials. The gold seed crystal layer is used for making a conductive layer for a subsequent electroplating process, so that the film coverage rate of the bottom of the back hole process of bias sputtering has high requirements, the situation that metal on the hole wall falls off in the subsequent process can be caused due to the low film coverage rate of the adhesion layer, the plating process cannot be normally carried out due to the poor coverage rate of the gold seed layer, and the performance of a device is affected through verification.

Taking the application material 5500 as an example, as shown in fig. 1, in a normal chamber, a motor (motor)1 'rotates to drive a magnet (magnet) 2' to rotate so as to restrain plasma (plasma) and increase secondary electrons to ensure continuous sputtering, argon is introduced into a cavity 7 'to ensure continuous sputtering, and cooling circulating water of a target (target) 3' ensures that heat during sputtering is taken away in time. There is the adapter in the below of target 3 ', and shade 8' is adorned on the adapter, comes to shelter from unnecessary sputter ion, avoids its other region that sputter the cavity, and the clamping ring can be pushed up to the position that breaks away from with the shade when carrying out the technology to ensure that radio frequency power can not loaded at the cavity shell, slide holder has elevating system, guarantees the target interval of different demands. The inside of the wafer carrying table is provided with cooling water circulation and an argon pipeline loaded at the back of the wafer.

In the normal process, the wafer is jacked up by the wafer carrying platform (Pedestal), the wafer is tightly pressed on the wafer carrying platform under the action of the gravity of the compression ring (clamp ring)4 ', and at the moment, the argon gas passing through the back pipeline fills the gap between the wafer (wafer)5 ' and the wafer carrying platform (Pedestal)6 ' in the process to be used as a heat conduction medium, so that the heat can be better taken away by circulating water, and the purpose of cooling the wafer can be achieved. In the case of a high temperature process, the wafer is uniformly heated by uniformly conducting heat through the argon in the backside pipe.

However, in actual production, sputtering heavy metal, for example, gold (AU), generates a large amount of heat, and experiments show that when a chamber with such a structure is used for a manufacturing process, the process temperature of the first few wafers can be well controlled, after the few wafers are processed, the temperature starts to gradually rise to cause the wax adhered to the wafers to dissolve and pollute the wafers, and after the chamber is opened, the temperature of the pressure ring is found to be very high. Because the process glues and waxes require less than 100 degrees celsius for good adhesion, such mechanisms cannot be used in large scale production.

Disclosure of Invention

The invention provides a low-temperature deep hole bias sputtering device, which aims to solve the problem that a low-temperature process cannot be realized when an Endura 5500 sputtering platform which is an application material sputters some metals and meet the low-temperature requirement that a workpiece surface coating is not melted in actual production.

The invention solves the technical problems through the following technical scheme:

the invention provides a low-temperature deep hole bias sputtering device, which comprises a target material, a cavity and a wafer carrier arranged in the cavity, and is characterized in that a cavity adapter is additionally fixed between the target material and the cavity, the cavity adapter is connected with an adapter water inlet pipe and an adapter water outlet pipe, a cooling disc for placing a wafer is fixed on the wafer carrier, an upper shade and a lower shade are placed in the cavity adapter, the top of the upper shade is fixed on the cavity adapter, the wall of the lower part of the upper shade is provided with a plurality of through holes along the circumferential direction, the wall of the lower shade is provided with a strip adjusting hole corresponding to the through holes along the circumferential direction, the lower part of the upper shade is sleeved in the lower shade, a corresponding strip adjusting hole and the through hole are penetrated through by a bolt to fix the upper shade and the lower shade, and the bottom of the lower shade is fixed with a bottom plate, the wafer clamping device is characterized in that a center hole is formed in the bottom plate, a plurality of mounting holes are formed in the bottom plate along the circumferential direction, each insulating ceramic column is placed on the periphery of the edge of each mounting hole, each insulating ceramic column is sleeved in each fixing column, each fixing column is fixed on the bottom plate, the top of each insulating ceramic column is arranged at the top end of each T-shaped suspender, the bottom end of each T-shaped suspender is fixedly connected with the compression ring, the compression ring is arranged above the cooling disc, and a plurality of adjustable compression bars used for clamping wafers are arranged on the compression ring along the circumferential direction.

Preferably, the pressure ring comprises a pressure ring main body, the surface of the pressure ring main body is fixedly connected with the bottom end of the T-shaped suspender, the inner diameter of the compression ring main body is embedded with a reducing ring, the compression ring main body is provided with a plurality of compression bar adjusting grooves along the circumferential direction, the length direction of each compression bar adjusting groove is from the edge of the compression ring main body to the inner diameter direction, an adjustable compression bar is embedded in each compression bar adjusting groove, the adjustable pressure lever comprises a base, a long-strip slide block is fixed on the base and is matched in the corresponding pressure lever adjusting groove in a sliding way, the front end of the base is fixed with a cover, the cover is fixed with a pressure point, the pressure point faces the wafer and is used for pressing the wafer, each base and the strip-shaped sliding block are vertically provided with a fixed screw hole, the fixing screws sequentially penetrate through the fixing screw holes in the base and the strip-shaped sliding block and lock the pressing rod and the corresponding pressing rod adjusting groove.

Preferably, three pressure bar adjusting grooves are uniformly formed in the pressure ring main body along the circumferential direction.

Preferably, the cooling plate comprises a cooling plate main body, wafer pin holes matched with the pins in the cavity one by one are formed in the cooling plate main body along the circumferential direction so that the pins can penetrate through the wafer pin holes, a back air vent hole is formed in the center of the cooling plate main body, an air flue is formed in the surface of the cooling plate main body, a plurality of fixing holes are formed in the cooling plate main body along the circumferential direction, the cooling plate main body is fixed on the wafer carrying table through bolts through the fixing holes, and the surface of the cooling plate main body is used for bearing wafers.

Preferably, three wafer pin holes are uniformly distributed on the cooling disc main body along the circumferential direction.

Preferably, each fixed column all corresponds there is a safety cover, the safety cover covers the fixed column of establishing correspondence.

Preferably, the height of the inner cavity of the protective cover is larger than that of the T-shaped suspender.

Preferably, three through holes are uniformly formed in the wall of the lower portion of the upper mask along the circumferential direction.

Preferably, three mounting holes are uniformly formed in the bottom plate along the circumferential direction.

Preferably, the bottom end of the T-shaped suspender is in threaded connection with the pressing ring.

On the basis of the common knowledge in the field, the above preferred conditions can be combined randomly to obtain the preferred embodiments of the invention.

The positive progress effects of the invention are as follows:

according to the invention, the upper and lower shields are tightly combined with the cavity adapter with water cooling to improve the heat conduction in the cavity, and the press ring is hung below the shields, so that the press ring can not become a heat source for heating the wafer in the sputtering process because the sputtering metal is blocked by the shields, and the whole sputtering heat is basically taken away through the shields. The wafer is pressed through the pressing ring, meanwhile, the back gas flows through the back face of the wafer, the wafer carrying platform with the cooling disc in special design can also take away the heat of the wafer during sputtering, temperature uniform distribution during sputtering is guaranteed, through the design, the temperature of the wafer in the actual process is reduced, better repeated stability between batches is also met, and the low-temperature process can be produced in batches continuously.

Drawings

Fig. 1 is a schematic structural diagram of a normal chamber in the prior art.

FIG. 2 is a schematic structural diagram of a low-temperature deep-hole bias sputtering apparatus according to a preferred embodiment of the invention.

FIG. 3 is a cross-sectional view of a low-temperature deep-hole bias sputtering apparatus according to a preferred embodiment of the present invention.

Fig. 4 and 5 are schematic structural assembly views of the cooling plate, the pressure ring, the upper shield and the lower shield according to the preferred embodiment of the present invention.

FIG. 6 is an assembled cross-sectional view of the structure of the cooling plate, the pressure ring, the upper mask and the lower mask according to the preferred embodiment of the present invention.

Fig. 7 is a schematic structural diagram of insulating ceramic posts and fixing posts according to a preferred embodiment of the invention.

Fig. 8 is a schematic structural diagram of a pressure ring according to a preferred embodiment of the invention.

FIG. 9 is a schematic structural view of an adjustable pressure lever according to a preferred embodiment of the invention.

Fig. 10 is an assembly view showing the structure of the pressing ring and the adjustable pressing rod according to the preferred embodiment of the present invention.

Fig. 11 is a sectional view showing the structure of the pressing ring and the adjustable pressing rod according to the preferred embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

As shown in fig. 2, the present embodiment provides a low-temperature deep-hole bias sputtering apparatus, which includes a target 1, a cavity 2, and a slide holder 3 disposed in the cavity 2, wherein a cavity adapter 4 is additionally fixed between the target 1 and the cavity 2, and the cavity adapter 4 is connected with an adapter water inlet pipe 5 and an adapter water outlet pipe 6.

As shown in fig. 3-7, a cooling plate 7 for placing a wafer is fixed on the stage 3, an upper mask 8 and a lower mask 9 are placed in the cavity adapter 4, the top of the upper mask 8 is fixed on the cavity adapter 4, three through holes are uniformly formed in the wall of the lower portion of the upper mask 8 along the circumferential direction, a strip adjusting hole 10 corresponding to the through hole is formed in the wall of the lower mask 9 along the circumferential direction, the lower portion of the upper mask 8 is sleeved in the lower mask 9 and penetrates through the corresponding strip adjusting hole 10 and the through hole through a bolt 11 to fix the upper mask 8 and the lower mask 9, a bottom plate 12 is fixed at the bottom of the lower mask 9, a central hole is formed in the bottom plate 12, three mounting holes 13 are uniformly formed in the bottom plate 12 along the circumferential direction, and an insulating ceramic column 14 is placed on the edge periphery of each mounting hole 13, insulating ceramic post 14 cover is established in fixed column 15, each fixed column 15 all corresponds a safety cover 19, corresponding fixed column 15 is established to safety cover 19 cover, safety cover 19's inner chamber height is greater than T type jib 16 height, fixed column 15 is fixed in on bottom plate 12, and insulating ceramic post 14's top is arranged in on T type jib 16's top, T type jib 16's bottom and clamping ring 17 looks spiro union, cooling disc 7's top is arranged in to clamping ring 17, be provided with three adjustable compression bar 18 that are used for the wafer of cramping along the circumferencial direction on the clamping ring 17 evenly.

The cooling plate 7 includes a cooling plate main body 71, wafer pin holes 72 matched with pins in the cavity one by one are formed in the cooling plate main body 71 along the circumferential direction so that the pins can penetrate through the wafer pin holes, back air vent holes 73 are formed in the central position of the cooling plate main body 71, an air passage 74 is formed in the surface of the cooling plate main body 71, four fixing holes 75 are formed in the cooling plate main body 71 along the circumferential direction, the cooling plate main body 71 is fixed on the wafer stage 3 through the fixing holes 75 by bolts, and the surface of the cooling plate main body 71 is used for bearing wafers.

As shown in fig. 8-11, the pressure ring 17 includes a pressure ring main body 171, the surface of the pressure ring main body 171 is fixedly connected to the bottom end of the T-shaped suspension rod 16, a reducing ring 172 is embedded in the inner diameter of the pressure ring main body 171, three pressure rod adjusting grooves 173 are uniformly formed in the pressure ring main body 171 along the circumferential direction, the length direction of each pressure rod adjusting groove 173 is the direction from the edge of the pressure ring main body 171 toward the inner diameter, an adjustable pressure rod 18 is embedded in each pressure rod adjusting groove 173, the adjustable pressure rod 18 includes a base 181, a long slide block 182 is fixed on the base 181, the long slide block 182 is slidably fitted in the corresponding pressure rod adjusting groove 173, a cover 183 is fixed at the front end of the base 181, a pressure point 184 is fixed on the cover 183, the pressure point 184 is used for pressing a wafer toward the wafer, and a fixing screw hole 185 is vertically formed in each base 181, the adjustable pressing rod 18 and the corresponding pressing rod adjusting groove 173 are locked by the fixing screws 186 which are sequentially arranged through the fixing screw holes 185 on the base 181 and the long sliding block 182.

The general design of internal diameter of clamping ring main part 171 is 200mm to the most shade of cooperation uses, there is three screw hole on the clamping ring main part 11, is to use on the shade in order to cooperate the clamping ring, through the bottom of three screw hole hoist and mount at the shade.

The pressing ring main body 171 is provided with three pressing rod adjusting grooves 173 for inserting the adjustable pressing rods 18 respectively, the adjustable pressing rods 18 can move in the pressing rod adjusting grooves 173 to adjust positions to match with wafers of different sizes, the adjustable pressing rods 18 are provided with fixing screw holes 185 and fixing screws 186, and the adjustable pressing rods 18 can be fixed after the positions are adjusted.

The reducing ring 172 is used for matching wafers with different sizes or different sputtering ranges on the wafers, and if parts which do not need to be sputtered need to be shielded, only different reducing rings need to be replaced.

The shape of the adjustable pressure lever 18 is matched with the pressure lever adjusting groove 173 on the pressure ring 17, a cover 183 is designed at the front end of the adjustable pressure lever 18, and a pressure point 184 for directly fixing the wafer is arranged below the cover 183. In practical applications, the height of the pressure point 184 is usually controlled to be 1mm, and the cover 183 is in the range of 2mm or more than 2mm to effectively prevent the sticking.

The pressing ring 17 is provided with a pressing rod adjusting groove 173 for fixing and adjusting the length of the adjustable pressing rod 18, so that the adjustable pressing rod can adapt to wafers of different sizes and can adapt to the size requirement of non-standard wafers, the adjustable pressing rod 18 is provided with a cover 183 for preventing sticking, and the condition that the wafers and the adjustable pressing rod 18 are adhered due to the fact that the coating film on the wafers is too thick can be avoided.

In order to adjust the distance from the wafer to the mask conveniently, the mask is designed to be a combination form in the embodiment, the through holes in the upper mask 8 are aligned with different positions of the strip adjusting holes 10 in the lower mask 9, the corresponding strip adjusting holes 10 and the through holes are penetrated through by bolts 11 to fix the upper mask 8 and the lower mask 9, the strip adjusting holes 10 are used for adjusting the upper mask 9 and the lower mask 9, and the distance from the pressing ring to the wafer can be changed.

To avoid the entry of sputter ions through the mounting holes into the insulating ceramic posts 14, three cylindrical protective caps 19 are designed to protect the insulating ceramic posts 14. The fixing posts 15 are used to fix the insulating ceramic posts 14 to the lower shield 9, so that the T-shaped hanger rods 16 can move up and down in the insulating ceramic posts 14 to isolate the pressure ring 17 and the shield.

According to the invention, the cavity adapter 4 is additionally arranged between the target 1 and the cavity 2, the height of the cavity adapter 4 is increased, the path of sputtering ions can be increased, the deep hole coverage rate is increased, and a better deep hole filling effect is achieved. The cavity adapter 4 is filled with cooling water, and heat on the upper shield 8 and the lower shield 9 is taken away by low-temperature water through the cavity adapter 4.

The shield of the invention is divided into an upper shield 8 and a lower shield 9, wherein the upper shield 8 is fixed on the cavity adapter 4 by screws, and the lower shield 9 is fixed on the upper shield 8 by bolts 11 and can be adjusted in height up and down to meet the requirements of different target spacing. The whole upper mask 8 and the whole lower mask 9 are used for shielding sputtering ions from sputtering other areas of the cavity and also bear most of heat in the sputtering process. Because the heat-conducting pipe is fixed on the cavity adapter 4 with water cooling and is tightly fixed together through screws, and has a larger contact area, the heat can be quickly taken away.

The press ring 17 of the present invention is placed below the lower shroud 9 by the T-shaped hanger bar 16. The press ring 17 is lifted up by the wafer-carrying stage 3 during the process, and at this time, the press ring 17 and the lower mask 9 are insulated by the insulating ceramic posts 14 on the side wall of the T-shaped hanger bar 16, so that the rf power is loaded on the wafer-carrying stage 3 during the process, and if the rf power is not insulated, the rf power is applied to the chamber housing and does not serve the purpose of bias sputtering. Three protective covers 19 are distributed on the lower shield 9 and screwed thereon for protecting the insulating ceramic posts 14 for insulation and preventing the sputtered metal from depositing thereon and losing the insulation.

The aperture of the pressure ring 17 is larger than that of the lower shade 9, so that sputtering metal can not be directly sputtered on the surface of the pressure ring 17 to cause overheating of the pressure ring. The adjustable pressure bar 18 extends through the pressure bar adjustment slot 173 on the pressure ring to fix the wafer, so that only the adjustable pressure bar 18 can receive the heat during sputtering, and the heat conduction on the wafer by the pressure ring 17 is minimized. The front end of the adjustable pressure bar 18 is designed with a pressure point 184 for preventing sticking, so as to prevent the sputtering metal from depositing on the contact part of the adjustable pressure bar and the wafer when thicker metal is deposited, which causes the adhesion between the adjustable pressure bar and the wafer and results in product rejection.

Slide holder 3 has elevating system to realize reciprocating of wafer, the inside low temperature demand that has led to when guaranteeing the wafer sputtering of coolant water of the same expert of slide holder 3, slide holder 3 bottom leads to there is the argon gas pipeline, and there is special design's cooling plate 7 in the top, the structure that cooling plate 7 processed needs cooperation slide holder 3, there is the air vent 73 of gas in the back at central point, there is gas distribution's air flue 74 on the surface, the argon gas at back can be applyed at the wafer back, the wafer is with temperature transfer for the cooling plate, whole cooling plate relies on slide holder 3 of below to cool off self, the heat with the wafer that can be better is gone out through slide holder 3 conduction, thereby further increase the cooling effect.

The slide holder 3 drives the wafer on the cooling plate 7 to move upwards to contact with the pressure point 184 on the adjustable pressure lever 18, the adjustable pressure lever 18 completely presses the wafer on the cooling plate 7 along with the continuous rising of the slide holder 3, argon gas on the back starts to be introduced, and the process is normally carried out.

Through the redesigned cavity, the temperature between the chips can be lower than 90 ℃ in the metal sputtering process, and the requirements of a back gold process and the large-scale production of the products are met.

While specific embodiments of the invention have been described above, it will be appreciated by those skilled in the art that these are by way of example only, and that the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the spirit and scope of the invention, and these changes and modifications are within the scope of the invention.

Claims

1. A low-temperature deep hole bias sputtering device comprises a target, a cavity and a wafer carrying table arranged in the cavity, and is characterized in that a cavity adapter is additionally and fixedly arranged between the target and the cavity, the cavity adapter is connected with an adapter water inlet pipe and an adapter water outlet pipe, a cooling disc for placing a wafer is fixedly arranged on the wafer carrying table, an upper shade and a lower shade are arranged in the cavity adapter, the top of the upper shade is fixed on the cavity adapter, a plurality of through holes are formed in the wall of the lower part of the upper shade along the circumferential direction, strip adjusting holes corresponding to the through holes are formed in the wall of the lower shade along the circumferential direction, the lower part of the upper shade is sleeved in the lower shade, corresponding strip adjusting holes and through holes are arranged through bolts to fix the upper shade and the lower shade, a bottom plate is fixedly arranged at the bottom of the lower shade, and a central hole is formed in the bottom plate, a plurality of mounting holes are formed in the bottom plate along the circumferential direction, each insulating ceramic column is placed on the periphery of the edge of each mounting hole, each insulating ceramic column is sleeved in each fixing column, each fixing column is fixed on the bottom plate, the top of each insulating ceramic column is arranged at the top end of each T-shaped suspender, the bottom end of each T-shaped suspender is fixedly connected with the compression ring, the compression ring is arranged above the cooling disc, and a plurality of adjustable compression rods used for clamping wafers are arranged on the compression ring along the circumferential direction.

2. The low temperature deep hole bias sputtering apparatus of claim 1, wherein said pressure ring includes a pressure ring body, the surface of the compression ring main body is fixedly connected with the bottom end of the T-shaped suspender, a reducing ring is embedded in the inner diameter of the compression ring main body, a plurality of pressure bar adjusting grooves are arranged on the pressure ring main body along the circumferential direction, the length direction of each pressure bar adjusting groove is the direction from the edge of the pressure ring main body to the inner diameter, an adjustable pressure bar is embedded in each pressure bar adjusting groove, the adjustable pressure lever comprises a base, a long-strip slide block is fixed on the base and is matched in the corresponding pressure lever adjusting groove in a sliding way, the front end of the base is fixed with a cover, the cover is fixed with a pressure point, the pressure point faces the wafer and is used for pressing the wafer, each base and the strip-shaped sliding block are vertically provided with a fixed screw hole, the fixing screws sequentially penetrate through the fixing screw holes in the base and the strip-shaped sliding block and lock the pressing rod and the corresponding pressing rod adjusting groove.

3. The low-temperature deep-hole bias sputtering device according to claim 2, wherein three pressure bar adjusting grooves are uniformly formed in the pressure ring main body along the circumferential direction.

4. The low-temperature deep-hole bias sputtering device according to claim 1, wherein the cooling plate comprises a cooling plate main body, the cooling plate main body is circumferentially provided with wafer pin holes matched with the pins in the cavity one by one for the pins to pass through, a central position of the cooling plate main body is provided with a back-air vent hole, the surface of the cooling plate main body is provided with an air passage, the cooling plate main body is circumferentially provided with a plurality of fixing holes, the fixing holes fix the cooling plate main body on the wafer stage by bolts, and the surface of the cooling plate main body is used for bearing wafers.

5. The apparatus of claim 1, wherein the cooling disk body has three uniformly distributed holes for ejecting the wafer.

6. The cryogenic deep hole bias sputtering apparatus of claim 1, wherein each of said fixed posts is associated with a shield, said shield housing the associated fixed post.

7. The cryogenic deep hole bias sputtering apparatus of claim 6 wherein the height of the interior cavity of the shield is greater than the height of the T-boom.

8. The cryogenic deep hole bias sputtering apparatus according to claim 1, wherein three through holes are uniformly opened in a wall of a lower portion of the upper mask along a circumferential direction.

9. The low temperature deep hole bias sputtering apparatus according to claim 1, wherein three mounting holes are uniformly provided in the bottom plate along a circumferential direction.

10. The cryogenic deep hole bias sputtering apparatus of claim 1, wherein the bottom end of the T-shaped hanger bar is threadably connected to the pressure ring.