WO2022006927A1

WO2022006927A1 - Cvd reaction module of silicon carbide epitaxy apparatus

Info

Publication number: WO2022006927A1
Application number: PCT/CN2020/101899
Authority: WO
Inventors: 刘子优; 肖蕴章; 钟国仿; 陈炳安; 张灿
Original assignee: 深圳市纳设智能装备有限公司
Priority date: 2020-07-07
Filing date: 2020-07-14
Publication date: 2022-01-13
Also published as: CN111636098A

Abstract

A CVD reaction module of a silicon carbide epitaxy apparatus, comprising a quartz housing (100), a gas inlet flange (120), and a tail end flange (130). A heating layer (300) and a thermally-insulating layer (200) are provided within the quartz housing (100). The heating layer (300) is provided with multiple replaceable elements. The replaceable elements are different in the arc of the inner top surface. A tray (500) used for placing a wafer is provided in an operation chamber. A lining (310/320) is provided in the heating layer (300) at the periphery corresponding to the tray (500). A top plate (600) used for supporting the tray (500) is provided below the tray (500). A lifting/lowering rod (810) extends outward from the bottom of the top plate (600). The beneficial effects are: when the thickness of the lining (310/320) is increased to an extent that prevents the tray (500) from performing normally a CVD process, the position of the tray (500) is slightly raised to ensure that the CVD process can continue, and to ultimately achieve the goal of extending the service life of the lining (310/320), and by replacing the heating layer (300) with one having a differently arced top surface, the temperature field of the operation chamber can be adjusted, thus increasing the uniformity of the temperature in the operation chamber, and increasing the uniformity of the thickness of a film formed on the wafer.

Description

A CVD reaction module of a silicon carbide epitaxy equipment

technical field

The invention relates to the technical field of CVD reaction, in particular to a CVD reaction module of a silicon carbide epitaxy equipment.

Background technique

Silicon carbide (SiC) material is the third-generation wide-bandgap semiconductor material following the first-generation semiconductor material silicon (Si) and the second-generation semiconductor (gallium arsenide, GaAs). The crystal structure of silicon carbide has the characteristics of homogeneity and polytype, and its basic structure is the tetrahedral structure of Si-C, which belongs to the close-packed structure. Its performance has superior performances such as higher forbidden band width, high critical breakdown electric field, high thermal conductivity, high carrier saturation drift speed, etc. It is used in semiconductor lighting, power electronic devices, lasers, detectors and other fields. Huge prospects.

In CVD equipment, temperature uniformity is one of the important parameters to ensure process quality. With the demand for product quality and the increase in wafer size, the requirements for uniformity are more stringent. At the same time, during the CVD process, a large number of reaction sources will be deposited outside the wafer. When the accumulation of by-products exceeds a certain level, the equipment needs to be maintained, which is one of the main factors affecting the continuous production of the equipment. Due to the special properties of the third-generation semiconductor silicon carbide, silicon carbide by-products are not easy to remove, resulting in increased replacement frequency of parts, reduced continuous production time, and increased costs. Therefore, in the competition in the third-generation semiconductor field, extending the continuous use time of equipment and cost control are crucial.

SUMMARY OF THE INVENTION

In view of the defects in the prior art, the present invention provides a CVD reaction module of a silicon carbide epitaxy equipment, which can improve the stability of the CVD process and prolong the maintenance period of the equipment.

The present invention provides a technical solution as follows: a CVD reaction module of a silicon carbide epitaxy equipment, comprising a quartz shell with openings at both ends, wherein the openings at both ends of the quartz shell are sealed with air inlet flanges and The rear end flange, the quartz shell, the inlet flange and the rear end flange are enclosed into a vacuum chamber, the chamber is provided with a heating layer and a thermal insulation layer covering the heating layer, the heating layer The cross section of the heating layer is in the shape of an oblong hole, the heating layer is provided with a hollow working cavity and both ends are open, the opening of the working cavity is opposite to the opening of the quartz shell, and the heating layer has a plurality of replacement parts , the radian of the inner top surface of each replacement part is different, an air intake guide is arranged between the air inlet flange and the opening of the heating layer, and a tray for holding wafers is also arranged in the working chamber, so A lining is also arranged around the corresponding tray in the heating layer, the air intake guide is located inside the lining, a top tray is provided below the tray for supporting the tray, and the bottom of the top tray extends outwards A lifting rod is extended, and the lifting rod extends outward through the heating layer, the thermal insulation layer and the quartz shell in turn. The top plate and the lifting rod are also provided with a rotating assembly for driving the rotation of the tray. A lift assembly for driving the lift rod to move up and down is also provided.

The beneficial effects of the above technical solutions are: the tray can be lifted and lowered by the drive of the lifting rod, when the wafer needs to be taken, the tray can be raised to the predetermined transfer position, the external manipulator can more conveniently catch the tray, and the tray is on the top. After the tray is lowered, it is separated from the top tray. The robot takes out the tray and the wafer from the tail flange, and the same is true for placing the wafer. With the function of raising and lowering the tray, there are more position options for process parameters, which can be calculated according to the accumulated thickness of by-products on the surface of the lining for a long time. , so that the tray exceeds the height of the by-products on the surface of the inner village, so as to ensure that the CVD process can continue, and finally achieve the purpose of prolonging the service life of the inner lining.

Further, a set of mixed gas inlets and a set of protective gas inlets are provided on the intake flange, and a mixed gas channel and a protective gas channel are provided on the intake guide corresponding to the intake flange.

Further, the mixed gas channel is divided into independent channels with the same number of mixed gas inlets by a partition plate, and a diversion ramp is arranged above the mixed gas channel, and the diversion ramp is inclined toward the direction of the tray. The independent channel makes the mixed gas entering the working chamber more uniform, which ensures better effect of the CVD process.

Further, the protective gas passage includes a plurality of ventilation holes, and the ventilation holes are arranged around the edge of the air intake guide.

Further, the inner liner includes an intake end liner and an exhaust end liner that are butted together, the intake end liner and the exhaust end liner are close to the inner wall of the heating layer, and the intake end liner The docking position with the exhaust end liner is the center line of the tray, and the positions of the intake end liner and the exhaust end liner corresponding to the tray are provided with arc gaps. The inner lining of the intake end and the inner lining of the exhaust end that are butted together are easier to be removed from the heating layer for replacement, and the arc notch set just encloses the tray after the docking, so as to avoid a large gap between the lining and the tray.

Further, the rotating assembly includes an air channel arranged in the lift rod and the top plate, an arc-shaped air guide groove is arranged at the bottom of the tray, and the tray rotates under the driving of the gas introduced by the lift rod. During the CVD process, the rotating tray enables a more uniform deposition layer to be formed on the wafer.

Further, the bottom of the tray is provided with a boss extending downward, the edge of the top plate is provided with an enclosure matching the boss, and the boss is located in the enclosure. The enclosure can prevent the tray from being disengaged from the top tray when rotated.

Further, the bottom of the lift rod is also provided with an observation window, and the bottom of the tray is provided with a straight groove at the position facing the central air channel.

Further, the rotating assembly includes a first motor disposed at the lower end of the lift rod, and the output shaft of the first motor is perpendicular to the plane where the top plate is located and is fastened to the top plate through the lift rod.

Further, the manufacturing material of the heating layer is graphite or silicon carbide, and an induction coil for providing heating energy is wound around the quartz shell.

Further, the lifting rod includes a heat insulation section close to the heating layer and an overhanging section extending outward, and a bellows for dynamic sealing is further arranged between the outer end of the overhanging section and the quartz shell.

Further, the quartz shell is provided with a bracket at a position corresponding to the bottom of the thermal insulation layer.

Description of drawings

In order to illustrate the specific embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that are required in the description of the specific embodiments or the prior art. Similar elements or parts are generally identified by similar reference numerals throughout the drawings. In the drawings, each element or section is not necessarily drawn to actual scale.

1 is a schematic structural diagram of an embodiment of the present invention;

2 is an exploded view of an embodiment of the present invention;

3 is a cross-sectional view of an embodiment of the present invention;

4 is a schematic structural diagram of an air intake guide in an embodiment of the present invention;

5 is a schematic structural diagram of a tray and a top tray in an embodiment of the present invention;

Fig. 6 is a replacement part of the heating layer in the embodiment of the present invention;

Fig. 7 is another replacement part of the heating layer in the embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a rotating assembly in Embodiment 2 of the present invention.

Reference numerals: quartz shell 100, induction coil 110, inlet flange 120, mixed gas inlet 121, protective gas inlet 122, tail flange 130, insulation layer 200, heating layer 300, inlet lining 310, Exhaust end liner 320, intake guide 400, mixed gas channel 410, ventilation hole 420, guide ramp 430, tray 500, boss 510, air guide groove 511, straight groove 512, top plate 600, The enclosure 610 , the heat insulation section 620 , the overhang section 630 , the bellows 640 , the air channel 650 , the elevator 700 , the driving rod 710 , the installation platform 711 , the rack 720 , the gear 730 , the first motor 800 , and the lifting rod 810 .

detailed description

Embodiments of the technical solutions of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are only used to more clearly illustrate the technical solutions of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

It should be noted that, unless otherwise specified, the technical or scientific terms used in this application should have the usual meanings understood by those skilled in the art to which the present invention belongs.

Example 1

As shown in FIGS. 1-5 , this embodiment provides a CVD reaction module of a silicon carbide epitaxy device, CVD is vapor deposition, and the reaction module includes a quartz shell 100 with open ends at both ends. The cross section of the quartz shell 100 In the shape of an oblong hole, the openings at both ends of the quartz shell 100 are sealed with an inlet flange 120 and a rear end flange 130 respectively. A vacuum chamber is enclosed, and the chamber is provided with a heating layer 300 and an insulating layer 200 wrapped around the heating layer 300 . The cross section of the heating layer 300 is also in the shape of an oblong hole. The heating layer 300 is provided with a hollow working cavity with open ends at both ends, and the opening of the working cavity is opposite to the opening of the quartz shell 100 . The oblong hole type heating layer is closer to the shape of the wafer cross section, and has more advantages in temperature uniformity than the round heating layer and the square heating layer.

In order to better adjust the temperature field in the working chamber, a plurality of replacement parts are prepared for the heating layer 300, and the inner top surface of each replacement part has a different curvature, and the top surfaces of the multiple replacement parts include downward protrusions and inward depressions Specifically, the heating layer can adjust the temperature of the wafer according to the different process results. If the central film thickness of the wafer is more different than the edge film thickness, it means that the temperature field in the working chamber is not uniform. The heating layers on the top surface of different radians can adjust the temperature field in the working chamber, so that the temperature in the working chamber is more uniform, thereby making the thickness of the film formed on the wafer more uniform. An air inlet guide 400 is provided between the ports, and the mixed gas for CVD reaction is connected by the air inlet flange 120 and enters the working chamber along the air inlet guide 400. For the round tray 500, the mixed gas forms a target precipitation layer on the wafers in the tray 500 after entering the working chamber, and an exhaust pipe is also connected to the tail flange 130 to ensure that the mixed gas can flow continuously in the working chamber .

The heating layer 300 is also provided with a lining around the corresponding tray 500 for catching the mixed gas deposits falling outside the wafer and keeping the heating layer 300 clean. The air intake guide 400 is located in the lining. The bottom of the tray 500 is provided with a top plate 600 for supporting the tray 500, and the bottom of the top plate 600 extends outward with a lifting rod, and the lifting rod passes through the heating layer 300, the thermal insulation layer 200 and the quartz in turn. The casing 100 extends outward, the top plate 600 and the lifting rod are also provided with a rotating assembly for driving the tray 500 to rotate, and the quartz casing 100 is also provided with a lifting assembly for driving the lifting rod to move up and down. The quartz shell 100 is provided with a bracket at a position corresponding to the bottom of the thermal insulation layer 200 . It is ensured that the thermal insulation layer 200 and the heating layer 300 can be fixed in the quartz case 100 .

The tray 500 can be raised and lowered under the drive of the lift rod. When the wafer needs to be taken out, the tray 500 can be raised to a predetermined transfer position. The external robot can more easily catch the tray 500. After the top tray 600 is lowered, the tray 500 To achieve separation from the top plate 600, the robot takes out the tray 500 and the wafer from the tail flange 130, and the same is true for placing the wafer. Closable switch. With the function of lifting the tray 500, the process parameters have more location options, which can be calculated according to the accumulated thickness of the by-products on the lining surface for a long time. It is raised slightly so that the tray 500 exceeds the height of the by-products on the surface of the inner village, so as to ensure that the CVD process can continue, and finally achieve the purpose of prolonging the service life of the inner lining.

In order to make the mixed gas entering the working chamber more uniform, a set of mixed gas inlets 121 and a set of protective gas inlets 122 are provided on the intake flange 120 , and the intake guide 400 is provided corresponding to the intake flange 120 There are mixed gas passages 410 and protective gas passages. The shielding gas blown into the working chamber prevents premature precipitation of the reaction source at the inlet of the liner.

The mixed gas channel 410 is divided into independent channels with the same number as the mixed gas inlets 121 by the partition plate. A guide ramp 430 is provided above the mixed gas channel 410 , and the guide ramp 430 faces the tray 500 . inclined direction. The independent channel makes the mixed gas entering the working chamber more uniform, which ensures better effect of the CVD process. The protective gas channel includes a plurality of ventilation holes 420 , and the ventilation holes 420 are arranged around the edge of the air intake guide 400 .

In order to replace the inner liner more conveniently, the inner liner is set as the intake end liner 310 and the exhaust end liner 320 that are butted together, and the intake end liner 310 and the exhaust end liner 320 are close to the heating layer On the inner wall of 300, the butting position of the intake end liner 310 and the exhaust end liner 320 is the center line of the tray 500, and the positions of the intake end liner 310 and the exhaust end liner 320 corresponding to the tray 500 are both. A circular arc gap is provided. The air intake end liner 310 and the exhaust end liner 320 that are butted together are easier to be removed from the heating layer 300 for replacement, and the arc gap is set to enclose the tray 500 after the butt joint to avoid the occurrence of the lining and the tray 500 larger gap.

Further, the rotating assembly includes an air channel 650 disposed in the lift rod and the top plate 600, and an arc-shaped air guide groove 511 is disposed at the bottom of the tray 500. The air introduced by the tray 500 in the lift rod driven by the rotation. During the CVD process, the rotating tray 500 can form a more uniform deposition layer on the wafer. The lift rod includes a thermal insulation section 620 close to the heating layer 300 and an overhanging section 630 extending outward, and a bellows 640 for dynamic sealing is further provided between the outer end of the overhanging section 630 and the quartz shell 100 .

Further, the bottom of the tray 500 is provided with a boss 510 extending downward, and the edge of the top plate 600 is provided with an enclosure 610 matching the boss 510 , and the boss 510 is located in the enclosure. Block 610. The enclosure 610 can prevent the tray 500 from disengaging from the top tray 600 during rotation.

Furthermore, the bottom of the lift rod is also provided with an observation window, and the bottom of the tray 500 is provided with a straight groove 512 at the position where the bottom of the tray 500 is facing the air channel 650 . An optical detection device is provided at the observation window of the lift rod. The optical detection device can determine the rotation speed of the tray 500 through the identification of the straight groove 512 by the observation window. The optical detection device can also detect the temperature of the tray 500, which is convenient for subsequent process adjustment. Provide parameters.

Further, the heating layer 300 is made of graphite or silicon carbide, and the thermal insulation layer 200 is made of carbon felt. An induction coil 110 for providing heating energy is wound around the quartz shell 100 . After the induction coil 110 is energized, a magnetic field can be generated, and the heating layer 300 placed in the magnetic field will generate heat and heat up due to the eddy current effect.

The lift assembly includes a lifter 700, and a vertical drive rod 710 is movably arranged in the lifter 700. The part of the drive rod 710 extending out of the lifter 700 is fastened to the lifter rod. The lifter 700 is provided with a second The motor, the second motor is arranged horizontally, the output shaft of the second motor is drivingly connected with the drive rod 710 through a rack and pinion, the rack 720 is arranged along the length direction of the drive rod 710, the gear 730 meshes with the rack 720 and is connected with the second motor. The output shaft of the motor is fastened coaxially.

Example 2

The main structure of this embodiment is the same as that of Embodiment 1. The difference from Embodiment 1 is that this embodiment proposes a new implementation for the rotating assembly. Specifically, the rotating assembly includes a first motor disposed at the lower end of the lifting rod 810 . 800, the first motor 800 is fixedly arranged on the driving rod 710 of the elevator 700, the driving rod 710 is provided with a mounting platform 711 for installing the first motor 800, and the output shaft of the first motor 800 is perpendicular to the ceiling. The plane on which the disk is located is fastened to the top disk 600 through the lifting rod 810 . The rotation speed of the tray can be obtained by the rotation speed of the first motor 800 .

In the description of the present application, it should be understood that the terms in the present application are only used for the purpose of description, and should not be construed as indicating or implying relative importance or implicitly indicating the number of indicated technical features. In the description of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined.

In this application, unless otherwise expressly specified and limited, the terms "connected", "connected", "fixed" and other terms should be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integrated ; It can be an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

In the description of the present invention, numerous specific details are set forth. It will be understood, however, that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, systems and techniques have not been shown in detail in order not to obscure an understanding of this description.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features thereof can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention. The scope of the invention should be included in the scope of the claims and description of the present invention.

Claims

A CVD reaction module of a silicon carbide epitaxy equipment is characterized in that it comprises a quartz shell with openings at both ends, and the openings at both ends of the quartz shell are respectively sealed with an inlet flange and a tail flange, so The quartz shell, the inlet flange and the tail flange are enclosed into a vacuum chamber, the chamber is provided with a heating layer and a thermal insulation layer wrapped outside the heating layer, and the cross section of the heating layer is an oblong hole The heating layer is provided with a hollow working cavity with open ends at both ends, the opening of the working cavity is opposite to the opening of the quartz shell, the heating layer has a plurality of replacement parts, and each replacement part has an interior The curvature of the top surface is different, an air intake guide is arranged between the air inlet flange and the opening of the heating layer, and a tray for holding wafers is also arranged in the working chamber, and the heating layer corresponds to the tray A lining is also arranged around the lining, the air intake guide is located inside the lining, a top plate for supporting the tray is arranged below the tray, and a lifting rod extends outward from the bottom of the top plate, so The lifting rods extend outward through the heating layer, the thermal insulation layer and the quartz shell in turn. The top plate and the lifting rods are also provided with rotating components for driving the rotation of the trays. Lifting components for the lifting movement of the lifting rod.
The CVD reaction module of a silicon carbide epitaxy equipment according to claim 1, wherein a set of mixed gas inlets and a set of protective gas inlets are arranged on the inlet flange, and the inlet guides correspond to the inlets. The gas flange is provided with a mixed gas channel and a protective gas channel.
The CVD reaction module of a silicon carbide epitaxial equipment according to claim 2, wherein the mixed gas channel is divided into independent channels with the same number of mixed gas inlets by a partition, and the mixed gas channel is arranged above There are diversion ramps that slope in the direction of the trays.
The CVD reaction module of a silicon carbide epitaxial equipment according to claim 2 or 3, wherein the protective gas channel comprises a plurality of ventilation holes, and the ventilation holes surround the edge of the air inlet guide set up.
The CVD reaction module of a silicon carbide epitaxy equipment according to claim 1, wherein the lining comprises an inlet end liner and an exhaust end liner that are butted together, and the inlet end liner The inner lining of the intake end and the lining of the exhaust end are closely attached to the inner wall of the heating layer, the butting position of the inner lining of the intake end and the inner lining of the exhaust end is the center line of the tray, and the inner lining of the intake end and the inner lining of the exhaust end correspond to the tray There are arc gaps at the positions.
The CVD reaction module of a silicon carbide epitaxy equipment according to claim 1, wherein the rotating assembly comprises an air channel arranged in the lift rod and the top tray, and the bottom of the tray is provided with an arc The tray is driven by the gas introduced by the lifting rod to rotate.
The CVD reaction module of a silicon carbide epitaxial equipment according to claim 6, wherein the bottom of the tray is provided with a boss extending downward, and the edge of the top plate is provided with a boss matching the boss The enclosure, the boss is located in the enclosure.
The CVD reaction module of a silicon carbide epitaxy equipment according to claim 6, wherein the bottom of the lift rod is further provided with an observation window, and the bottom of the tray is provided with a straight groove at a position facing the air channel .
The CVD reaction module of a silicon carbide epitaxy equipment according to claim 1, wherein the rotating assembly comprises a first motor disposed at the lower end of the lift rod, and the output shaft of the first motor is perpendicular to the position where the top plate is located. The plane is fastened with the top plate through the lifting rod.
The CVD reaction module of a silicon carbide epitaxy device according to claim 1, wherein the heating layer is made of graphite or silicon carbide, and an induction coil for providing heating energy is wound around the quartz shell. .
The CVD reaction module of a silicon carbide epitaxy equipment according to claim 1, 6 or 8, wherein the lift rod comprises a heat insulating section close to the heating layer and an outwardly extending section, the outer section A bellows for dynamic sealing is also arranged between the outer end of the extension and the quartz shell.
The CVD reaction module of a silicon carbide epitaxy equipment according to claim 1, wherein a bracket is provided at a position of the quartz shell corresponding to the bottom of the thermal insulation layer.