Patent ID: 12198972

DETAILED DESCRIPTION OF THE EMBODIMENTS

Various embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the embodiments described here are merely used to illustrate and explain the present disclosure, and are not intended to limit the present disclosure.

In an existing process chamber including a high-temperature chuck, such as a device used in a stripping process, a bottom support column of the high-temperature chuck is often directly fixed on a bottom wall of the process chamber. The high-temperature chuck is connected to the process chamber. A large temperature difference between the high-temperature chuck and a cavity of the process chamber causes a large amount of heat transfer between the high-temperature chuck and the cavity of the process chamber. On one hand, it increases a thermal load of the high-temperature chuck (to maintain a high temperature of the high-temperature chuck, the high-temperature chuck itself and a part of the cavity need to be heated at the same time), causing unnecessary waste of energy. On the other hand, a temperature of the bottom of the cavity increases. It leads to an uneven temperature field inside the cavity, which not only affects stability of a semiconductor process, but also leads to a series of problems such as failures of components connected to the cavity. In addition, when the bottom support column of the high-temperature chuck and the process chamber cavity are sealed by an O-ring, a risk that the O-ring may fail at high temperature still exists. Replacing the O-ring with a sealing structure that can withstand extremely high temperatures will increase material cost of a process equipment.

To solve the above technical problems, the present disclosure provides a process chamber included in a semiconductor process device. As shown inFIGS.1to4, the process chamber includes a cavity1and a base2disposed in the cavity1. The base2includes a base body21and a support column24fixedly disposed at the bottom of the base body21. An interior of the support column24includes a receiving hole241that penetrates the support column24in an axial direction of the support column24. A fixed through-hole11is formed at the bottom of the cavity1. A bottom end of the support column24is fixedly arranged in the fixed through-hole11. The receiving hole241is connected to the outside of the process chamber through the fixed through-hole11.

The fixed through-hole11includes a positioning groove111formed on the bottom wall of the cavity1and a connection hole112penetrating from the bottom of the positioning groove111to an outer surface of the cavity1. A positioning plate2is formed on an outer wall of the support column24around an axis of the support column24. The positioning plate25is disposed in the positioning groove111. An annular thermal insulator3is sleeved on the support column24. The annular thermal insulator3is disposed between a bottom surface of the positioning plate25and the bottom of the positioning groove111(i.e., the bottom surface of the positioning groove111). The bottom end of the support column24is fixedly connected to the outer wall of the cavity1through a fixing member, and the support column24is subject to a downward pre-tightening force of the fixing member.

It should be noted that the receiving hole241of the support column24is used to receive cables, pipelines, and other structures between the base body21and other components outside the process chamber. For example, when the base2is used as the high-temperature chuck as shown inFIG.1, the base body21may include an upper pad and a lower pad that are stacked along a height direction (i.e., an axial direction of the base body21). Heating wire grooves with corresponding shapes are formed on opposite surfaces of the upper pad and the lower pad. The upper pad and the lower pad are connected through welding. The heating wire groove on the upper pad and the heating wire groove on the lower pad are coupled to form a heating wire hole in the base body21extending in a horizontal plane. A heating wire is disposed in the heating wire hole. The cable of the heating wire passes through the receiving hole241of the support column24and is connected to a power supply outside the process chamber. Driven by a current supplied the power supply, the heating wire heats the base body21and a wafer100carried thereon. In some embodiments, a cooling passage may be provided in the base body21, and an inlet pipe and an outlet pipe of the cooling passage may pass through the receiving hole241of the support column24and may be connected with a cooling source outside the process chamber. A coolant provided by the cooling source may circulate through the cooling passage in the base body21to cool the base body21, such that the base2can be quickly cooled, thereby facilitating maintenance and saving maintenance time.

In the embodiments of the present disclosure, the fixed through-hole11at the bottom of the cavity1includes the positioning groove111and the connection hole112penetrating from the bottom of the positioning groove111to the outer surface of the cavity1. The positioning plate25on the outer wall of the support column24is disposed in the positioning groove111. The bottom end of the support column24is fixedly connected to the outer wall of the cavity1through the fixing member, and is subject to the downward pre-tightening force of the fixing member. The support column24of the base2is locked downward by the pre-tightening force, such that the positioning plate25is pressed against the bottom of the positioning groove111through the annular thermal insulator3arranged around the support column24. While stably fixing the base2, the annular thermal insulator3is also used to separate the support column24from the cavity1. Thus, efficiency of heat transfer from the base2to the cavity1through the support column24is effectively reduced, the thermal load of the base2is reduced, reliability of components (i.e., the heating wire) in the base2is improved, and energy is saved. At the same time, the stability of the temperature field inside the process chamber is improved, failure risk of components connected to the process chamber is reduced, and the stability of the semiconductor process is improved.

In some embodiments, as shown inFIGS.1and4, a welding pad242is formed on the top of the support column24, and a welding groove is formed on the bottom of the base body21. The welding pad242is welded and fixed to the welding groove, thereby achieving a fixed connection between the base body21and the support column24.

In some embodiments, as shown inFIG.2, to improve a sealing effect of the process chamber, an annular sealing ring groove surrounding an axis of the annular thermal insulator3is formed respectively on the top and the bottom of the annular thermal insulator3. Annular sealing rings4are provided in both annular sealing ring grooves.

In some embodiments, as shown inFIG.2, to further reduce a heat transfer rate between the bottom end of the support column24and the cavity1, a thermal insulation gap34is arranged between sidewalls of the annular thermal insulator3and sidewalls of the positioning groove111. In some embodiments, the thermal insulation gap34has a size (i.e., a size in a radial direction of the annular thermal insulator3) of 2-3 mm. The thermal insulation gap34is used to reduce a contact area between the annular thermal insulator3and the cavity1, thereby further reducing the heat transfer rate between the bottom end of the support column24and the cavity1.

In some embodiments, the annular thermal insulator3may be made of a metal with a small thermal conductivity (e.g., less than 20 W/m·K), for example, a titanium alloy (having a thermal conductivity about 1/14 of aluminum).

In some embodiments, as shown inFIGS.5and6, to further reduce the heat transfer rate between the bottom end of the support column24and the cavity1, the annular thermal insulator3includes a first annular member31, a second annular member32, and a plurality of connecting members33. The first annular member31and the second annular member32are spaced apart along a height direction (i.e., a direction parallel to the axis of the annular heat insulator3). The plurality of connecting members33are distributed at intervals along a circumferential direction, and are connected between the first annular member31and the second annular member32. In some embodiments, to improve stability of the plurality of connecting members33between the first annular member31and the second annular member32, the plurality of connecting member33are distributed at equal intervals along the circumferential direction. In some other embodiments, as shown inFIG.6, four connecting members33are connected between the first annular member31and the second annular member32. Each of the plurality of connecting members33includes two side surfaces whose planes pass through the axis of the annular thermal insulator3, and an angle formed between the two side surfaces is about 5°.

In the embodiments of the present disclosure, each of the plurality of connecting member33connected between the first annular member31and the second annular member32has an extremely small horizontal cross-section, that is, being a thin-walled structure, which substantially reduces the heat transfer rate from top to bottom. For example, four connecting members33are connected between the first annular member31and the second annular member32, and the angle formed between the two side surfaces of each connecting member33is about 5°. A heat transfer area of the annular thermal insulator3for heat transfer from top to bottom will be reduced to 1/18 of an initial heat transfer area (i.e., 4*5°/360°), thereby substantially reducing the heat transfer rate between the bottom end of the support column24and the cavity1.

In some embodiments, as shown inFIGS.1to4, to improve uniformity of the downward pre-tightening force exerted by the fixing member on the support column24along the circumferential direction, a first connection plate27is arranged on the outer wall of the support column24around the axis of the support column24. The first connection plate27and the positioning plate25are spaced apart along the axial direction of the support column24and located at the bottom end of the support column24. The first connection plate27is fixedly connected to the outer wall of the cavity1through the fixing member. The first connection plate27is subject to the downward pre-tightening force of the fixing member.

It should be noted that the pre-tightening force exerted on the first connection plate27is evenly distributed along the circumferential direction. In the embodiments of the present disclosure, the fixing member exerts the downward pre-tightening force on the supporting column24through the first connection plate27surrounding the axis of the supporting column24, thereby improving the uniformity of the pre-tightening force distributed in the circumferential direction and improving the stability of the position of the base2in the process chamber.

In some embodiments, the fixing member and the first connection plate27may be tightly connected through a flange butt connection. For example, as shown inFIGS.1to4, the fixing member includes a second connection plate7and a plurality of fasteners6. The second connection plate7is arranged opposite to the first connection plate27and is in contact with the bottom surface of the cavity1. A plurality of first connection holes are formed in the second connection plate7penetrating the second connection plate7along a thickness direction (i.e., a direction parallel to the axis of the support column24). A plurality of second connection holes are formed in the first connection plate27. The plurality of first connection holes are arranged to correspond in a one-to-one correspondence to positions of the plurality of second connection holes. The plurality of fasteners6pass through the plurality of first connection holes and the corresponding plurality of second connection holes in sequence to fixedly connect the second connection plate7to the first connection plate27.

In the embodiments of the present disclosure, the fixing member includes the second connection plate7and the plurality of fasteners6. Both the first connection plate27and the second connection plate7include the flange structure. The second connection plate7has a diameter larger than a diameter of the connection hole112, such that a top surface of the second connection plate7presses against the bottom of the process chamber. Through tightening action of multiple fixing members, the first connection plate27may be pushed down uniformly in the circumferential direction, such that the positioning plate25can stably press against the bottom surface of the positioning groove111through the annular thermal insulator3to stably fix the base2in the process chamber.

Structures of the plurality of fasteners are not limited by the embodiments of the present disclosure. For example, each of the plurality of fasteners6may be a rivet, a bolt, or other suitable parts. In some embodiments, as shown inFIG.2, to conveniently assemble and disassemble the first connection plate27and the second connection plate7and to improve circumferential force uniformity of the first connection plate27, a snap ring5is arranged on the support column24. The snap ring5is located between the positioning plate25and the first connection plate27. The snap ring5is formed with a plurality of threaded holes penetrating the snap ring5along the thickness direction (i.e., the direction parallel to the axis of the support column24). Each of the plurality of fasteners6is a set screw. The first connection hole and the second connection hole are both smooth holes. The set screw passes through the second connection hole, the first connection hole, and the corresponding threaded hole in sequence from bottom to top, and is tightened in the threaded hole, such that the snap ring5is used to press down the first connection plate27to fixedly connect the first connection plate27to the second connection plate7.

In some embodiments, as shown inFIG.2, to further reduce the heat transfer rate between the bottom end of the support column24and the cavity1, a first thermal insulation gap271is arranged between the side wall of the first connection plate27and an inner wall of the connection hole112, and a second thermal insulation gap272is arranged between the first connection plate27and the second connection plate7.

In the embodiments of the present disclosure, the thermal insulation gaps are arranged between the side wall of the first connection plate27and the inner wall of the connection hole112and between the first connection plate27and the second connection plate7, thereby preventing direct or indirect (through the second connection plate7) heat transfer between the first connection plate27and the cavity1, and further reducing the thermal load of the base2. In some embodiments, both the first thermal insulation gap271and the second thermal insulation gap272are larger than 2 mm.

In some embodiments, as shown inFIGS.4,7, and8, to further improve the stability of the position of the base2, a positioning protrusion26is formed on the side wall of the positioning plate25, and a positioning notch is formed on the side wall of the positioning groove111. The positioning protrusion26with a corresponding shape is arranged in the positioning notch.

In the embodiments of the present disclosure, the positioning protrusion26is formed on the side wall of the positioning plate25, and the positioning notch with the corresponding shape is formed on the side wall of the positioning groove111, such that through a coupling relationship between the positioning protrusion26and the positioning notch, the base2is circumferentially positioned to limit a rotation angle of the base2, thereby ensuring the correct position of the base2after each disassembly, assembly, and maintenance.

In some embodiments, as shown inFIG.3, to improve accuracy of wafer position, an annular limiting protrusion23is formed on a bearing surface of the base body21. The annular limiting protrusion23surrounds along the axial direction of the base body21, and an outer surface of the annular limiting protrusion23is flush with the side wall of the base body21.

In the embodiments of the present disclosure, the annular limiting protrusion23is used to limit the wafer position. For example, when an outer diameter of the annular limiting protrusion23(i.e., a diameter of an outer contour) is approximately 310 mm, and an inner diameter (i.e., a diameter of an inner contour) is approximately 301 mm, a 12-inch wafer may be limited in the annular limiting protrusion23to prevent the wafer from horizontally shifting on the bearing surface of the base2. That is, the function of the annular limiting protrusion23is equivalent to a focus ring. The difference is that the annular limiting protrusion23in the present disclosure is formed as a part of the base2. For example, both the annular limiting protrusion23and the base2may integrally formed. Thus, the need for installing an independent focusing ring on the base2is eliminated. While the structure of the base2as well as installation and maintenance processes are simplified, the material cost of the semiconductor process device is also reduced.

In some embodiments, the height of the annular limiting protrusion23is approximately 1.5-2 mm. In some embodiments, the material of the base body21may be aluminum alloy, and a corrosion resistance layer is formed on the bearing surface of the base body21and the inner surface of the annular limiting protrusion23through a hard anodizing treatment or a natural anodizing treatment. The corrosion resistance layer prevents the base body21from being etched by plasma, extends the service life of the base body21, and protects a chamber environment from being polluted.

In some embodiments, as shown inFIGS.3,7,9, and10, to further improve an accuracy of a position of landing a wafer100on the bearing surface of the base2, an air guide groove22is formed on the bearing surface of the base body21. The air guide groove22includes a plurality of linear air guide grooves221evenly distributed along the circumferential direction of the base body21. Each linear air guide groove221extends along the radial direction of the base body21. The air guide groove22also includes a plurality of concentrically arranged annular air guide grooves222. Each annular air guide groove222surrounds along the axis of the base body21, and each annular air guide groove222intersects with the plurality of linear air guide grooves221.

In the embodiments of the present disclosure, the air guide groove22is formed on the bearing surface of the base body21. The air guide groove22includes the plurality of linear air guide grooves221and the plurality of annular air guide grooves222, such that during a process of landing the wafer100on the bearing surface, the gas between the wafer100and the bearing surface can be uniformly discharged to the surroundings under the guidance of the plurality of linear air guide grooves221that are evenly distributed in the radial direction. Even if air pressures and gas flow rates are different at different linear air guide grooves221, the gas at a higher pressure may flow appropriately to a position having a lower pressure under the circumferential guidance of the plurality of annular air guide grooves222. Thus, the gas between the wafer100and the bearing surface is ensured to discharge uniformly in the circumferential direction. When descending to the bearing surface, the horizontal position deviation of the wafer100is prevented, thereby improving the accuracy of the wafer100position.

In some embodiments, as shown inFIGS.7,9, and10, one of the plurality of annular air guide grooves222is located at a peripheral edge of the bearing surface and is in contact with the annular limiting protrusion23(the inner side). As such, an annular air guide groove222located at the peripheral edge plays a buffering effect on the gas flowing above the annular limiting protrusion23, further improving the circumferential uniformity of the flow field of the discharged gas. In some embodiments, as shown inFIGS.7,9, and10, the air guide groove22includes eight linear air guide grooves221and two annular air guide grooves222. One of the two annular air guide grooves222is arranged close to the center of the bearing surface, and another annular air guide groove222is located at the peripheral edge of the bearing surface and is in contact with the annular limiting protrusion23.

In some embodiments, the base body21includes a plurality of pinholes28distributed around the axis of the base body21. The plurality of pinholes28penetrate the base body21along the axial direction of the base body21to allow wafer ejection pins to pass through the base body21from the bottom of the base body21to the top of the bearing surface of the base body21and to support the wafer100. Each pinhole28corresponds to a linear air guide groove221passing through the pinhole28.

In some embodiments, each pinhole28corresponds to a linear air guide groove221passing through the pinhole28. As shown inFIG.10, when the wafer100gradually descends as the wafer ejection pins descends, the gas between the wafer100and the bearing surface is discharged along three paths shown inFIG.10. That is, a first portion of the gas is discharged horizontally in the circumferential direction (air guide direction1), a second portion of the gas is discharged circumferentially (air guide direction2) under the guidance of the air guide groove22, and a third portion of the gas is discharged downward through the pinholes28under the guidance of the plurality of air guide grooves221of the air guide groove. As such, a guide function of the air guide groove22is combined with the pinhole28structure of the base to further improve the uniform discharge of the gas between the wafer100and the bearing surface along the circumferential direction, thereby improving the accuracy of the wafer100position.

In the process chamber provided by the present disclosure, the fixed through-hole11at the bottom of the cavity1includes the positioning groove111and the connection hole112penetrating from the bottom of the positioning groove111to the outer surface of the cavity1. The positioning plate25on the outer wall of the support column24is disposed in the positioning groove111. The bottom end of the support column24is fixedly connected to the outer wall of the cavity1through the fixing member, and is subject to the downward pre-tightening force from the fixing member. As such, the support column24of the base2is locked downward by the pre-tightening force, and the positioning plate25is pressed against the bottom of the positioning groove111through the annular thermal insulator3sleeved on the support column24. While stably fixing the base2, the annular thermal insulator3is used to separate the support column24from the cavity1, effectively reduce the efficiency of heat transfer from the base2to the cavity1through the support column24, reduce the thermal load of the base2, improve the reliability of the components in the base2, and save energy. At the same time, the stability of the temperature field inside the process chamber is improved, the failure risk of components connected to the process chamber is reduced, and the stability of the semiconductor process is improved.

It can be understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principles of the present disclosure, but the present disclosure is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present disclosure, and these modifications and improvements are also regarded as within the scope of the present disclosure.