TW201929118A - Shadow device for semiconductor processing chamber and method using the same - Google Patents

Abstract

The invention relates to a shadow device used for semiconductor processing chamber, including a shadow ring and a support assembly. The shadow ring has a bottom surface provided with bumps for avoiding contact between a susceptor in the chamber and the shadow ring. The support assembly connects to the shadow ring, and a bottom surface of the support assembly is configured to contact with one or more protrusions such that the shadow ring is supported at a position above the one or more protrusions.

Description

Masking device for semiconductor processing cavity and use method thereof

The invention relates to the field of semiconductor wafer processing, in particular to a shielding device in a semiconductor processing chamber, which is used to prevent deposition around the wafer during processing.

Semiconductor processes include deposition processes, such as chemical vapor deposition (CVD), which can form various films on wafers or substrates to make semiconductor devices, such as integrated circuits and semiconductor light-emitting devices. The first figure is a partial schematic diagram showing that a thin film (12) formed by the deposition process is formed on a wafer or substrate (11) supported by a carrier disk (10), wherein the carrier disk (10) There is a stepped structure (13) around, such as a ceramic ring, configured to prevent wafer level shift. In addition, the ceramic ring can be combined with a heating means to heat the wafer. During the deposition process, there is no obstruction or shielding between the nozzle and the wafer, and the thin film formed by the deposition may extend to the edge or even the side of the wafer (as shown in the first figure). This part of the film has the opportunity to collide with the raised portion of the ceramic ring (13) of the carrier plate (10) and cause the film to crack. Particles and dust caused by cracking will adhere to the surface of the film (12) and form defects.

Therefore, a shielding device is developed to cover the edge of the wafer or the substrate to prevent gas from being deposited on the edges and sides of the wafer, and even to use the characteristics of the structure to guide the gas to the area to be processed of the wafer.

US issued patent No. US5328722A discloses a shielding means for a semiconductor processing cavity, which provides a shielding ring with an inclined structure. With the inclined structure, the shielding ring can bear on the wafer carrier, and at the same time, a bottom surface inside the shielding ring contacts and covers the edge of the wafer to prevent deposition from occurring on the edge and side of the wafer. In addition, Chinese Published Patent Application No. CN102714146A discloses a shielding method for a semiconductor processing cavity, which provides a shielding ring with a pin structure and a wafer carrier disk. Through the cooperation of the latch structure, the shielding ring and the carrier disk can be aligned and aligned, while the inner edge of the shielding ring contacts and covers the edge of the wafer to prevent unnecessary deposition. However, these conventional shielding methods are in contact with the wafer, which may cause problems such as defects on the wafer surface due to pressure, or particles that may fall on the wafer surface due to collision between components. In addition, these conventional masking rings lack adjustable capabilities. In the unprocessed time, the shielding ring generally can only be maintained at a height in the processing cavity. However, when the height of the carrier tray must be changed due to processing requirements today, the position of the shielding ring may not be suitable for the changed processing. For example, when the carrier disk must be closer to the sprinkler head for processing, the shielding ring and the carrier disk must collide, and an appropriate gap cannot be maintained between the two.

Therefore, it is necessary to develop a shielding device that does not interfere with the wafer, and the shielding device also has an adjustable mechanism, and even develop a semiconductor processing cavity suitable for such a shielding device.

References in this specification to any prior disclosure (or its derivative information) or any known matter are not and should not be considered as confirmations or acknowledgements or suggestions of any kind, that is, previous applications (or their derivative information) or known matters Objects form part of general common knowledge in the fields covered by this specification.

An object of the present invention is to provide a shielding device for a semiconductor processing chamber, wherein the processing chamber has a top, a bottom, a side wall, and a carrier plate. The shielding device includes: a shielding ring having a top surface and a bottom surface, and the bottom surface of the shielding ring has a plurality of bumps for preventing the carrier disk from contacting the shielding ring; A supporting element is connected to the shielding ring, and a bottom surface of the supporting element is configured to contact one or more protrusions in the processing cavity, so that the shielding ring is supported on a protrusion above the protrusion. Position, and the shielding ring can move between the position and the top of the processing chamber.

In a specific embodiment, the thickness of the inner edge of the shielding ring is smaller than the thickness of the outer edge of the shielding ring.

In a specific embodiment, the plurality of bumps are spherical bumps or conical bumps.

In a specific embodiment, the top surface of the supporting element is connected to the bottom surface of the shielding ring via a detachable connection means.

In a specific embodiment, the supporting element is a ring body, and the ring body has a height.

In a specific embodiment, the top surface of the supporting element is connected to the bottom surface of the shielding ring.

In a specific embodiment, an outer side of the shielding ring has a plurality of ears, and the plurality of ears are connected to the supporting element. The support element includes a plurality of support blocks, and each support block has a coupling hole for receiving the ear, so that the plurality of support blocks are respectively connected to each ear of the shielding ring.

Another object of the present invention is to provide a method for using a shielding device for a semiconductor processing chamber, wherein the processing chamber has a top, a bottom, a side wall, and a carrier tray capable of lifting and carrying a wafer. . The method includes: providing one or more protrusions, the protrusions extending from the side wall; providing a shielding device as described above; raising the carrier plate until a gap is formed between the carrier plate and the bottom surface of the shielding ring; The gap is such that the inner edge of the shielding ring is located above a periphery of the wafer.

In a specific embodiment, the gap is formed by the plurality of bumps on the bottom surface of the shielding ring contacting the bearing plate. A ceramic ring is provided on a top of the carrier disk, and the gap is formed by the plurality of bumps on the bottom surface of the shielding ring contacting the ceramic ring of the carrier disk.

In a specific embodiment, a side wall of the processing chamber includes a suction ring, the suction ring has an inner wall, and the protrusion extends from the inner wall of the suction ring.

It should be understood that the broad forms of the invention and their respective features may be used in combination, interchangeably, and / or independently, and are not intended to limit the reference to the separate broad forms.

In this specification and the scope of the following patent applications, unless the context requires otherwise, the words "including" and variations such as "including" or "including" will be understood to imply the inclusion of the stated group or step of integers, but Does not exclude any other integers or groups of integers.

The second figure shows a semiconductor processing chamber (20) and a shielding device (30) for the semiconductor processing chamber of the present invention. The processing chamber has a top (210), a bottom (220), a side wall (230), and a carrier tray (240). The top (210), bottom (220), and side walls (230) are coupled to each other to define the cavity space.

The top portion (210) may be coupled to the upper end of the side wall (230) by a close fitting means. The top (210) contains one or more spray assemblies (211), which are coupled below the top (210) and provide a gas for the deposition process. Generally speaking, the shower element (211) is a part of a reactive gas supply system, and includes one or more pipes and a plurality of shower heads. In some embodiments, the shower assembly (211) may also include electrodes or heating devices.

The bottom (220) may be coupled to the lower end of the side wall (230) by a dense means, or both may be integrally formed so that the top (210) and the bottom (220) serve as upper and lower limits of the cavity space. The bottom (220) also provides a lifting channel, allowing a portion of a lifting device, such as a support shaft (241) for lifting the carrying tray (240), to pass through the bottom (220) and perform a lifting operation. Although not shown in the figures, in some embodiments, the bottom (220) may be coupled to a portion of the extraction system and / or a portion of the non-reactive gas supply system.

The side wall (230) extends between the top (210) and the bottom (220), and is substantially formed in the form of a cylinder. The side wall (230) has a transfer channel (231) through which wafers and substrates are loaded or unloaded from the processing chamber (20). The side wall (230) can be coupled to a part of the exhaust system, such as the suction ring (232) in the figure, which is coupled to one or more suction pumps, so that the reacted exhaust gas is discharged out of the cavity (20). outer. As shown, the suction ring (232) may be independently formed by one or more other components, and forms a suction channel (233), which is defined in the inner surface of the side wall (230). Generally speaking, the suction ring (232) is disposed on the upper half of the side wall (230), and the inner surface of the suction ring (232) has a plurality of holes (234) to allow the reaction gas to flow from the processing area to the suction channel (233). ).

The bearing plate (240) is a plate body having a bearing surface (top surface) and a bottom surface. The bottom surface of the bearing plate (240) is coupled to the lifting shaft (241) of the aforementioned lifting device. Before the processing is started, the carrier tray (240) is maintained in a first position, as shown in the second figure, in order to receive the wafer or substrate to be processed through the transfer channel (231). The transfer channel (231) and the carrier plate (240) can be appropriately configured to cooperate with the operation of a robot arm. The carrier tray (240) may include a heating means for heating the wafer or the substrate it carries. For example, a heating coil or an infrared device may be embedded in the disk body. In this embodiment, the carrying mask of the carrying tray (240) has a stepped structure (242) arranged around the carrying surface to prevent the wafer from shifting, as shown in the first figure. However, in other embodiments, the step structure is not necessarily included.

The side wall (230) of the present invention further includes one or more protrusions (235) for supporting the shielding device (30) of the present invention. The protruding portion (235) extends from the side wall (230) to the cavity space and is not above the transmission channel (231). In an embodiment, the protrusion (235) may be an annular platform surrounded along the side wall (230). In another embodiment, the number of the protrusions (235) is at least two or more. The protrusions (230) are adequately configured to support the shielding device (30) of the present invention. As shown in the illustrated embodiment, the protruding portion (235) is integrally formed with a side wall (not numbered) of the suction ring (232). In particular, the vertical size of the side wall of the suction ring (232) is greater than the vertical size of the suction channel. . It is worth noting that the advantage of integrally forming the protrusion (235) and the suction ring (232) is that the mechanical strength of the suction ring (232) can be maintained, and the thermal stress generated by the suction ring (232) at high temperature is guaranteed. Not enough to cause fragmentation itself.

With the protruding portion (235), the shielding device (30) is supported at a height in the cavity space and maintains a proper gap with the side wall (230). The shielding device of the present invention includes a shielding ring (310) and a supporting component (320). Referring also to the fourth figure, the shielding ring (310) has a top surface (311) and a bottom surface (312), which respectively face the top of the cavity and the bearing plate. The shielding ring (310) includes a tapered portion, that is, tapering toward the cavity space, so that a part of the top surface (311) of the shielding ring (310) is inclined downward toward the center of the cavity. In other words, the thickness of the inner edge of the shielding ring is smaller than the thickness of the outer edge of the shielding ring. The inclined surface helps guide the reaction gas to the wafer or substrate. The bottom surface (312) of the shielding ring (310) substantially maintains a horizontal plane. The shielding ring (310) extends laterally from the side wall (230) by an appropriate distance to ensure that the bottom surface (312) of the shielding ring (310) is sufficient to cover the periphery of the carrying surface of the carrying tray (240) and the edge of the wafer or substrate to be processed. . The bottom surface (312) of the shielding ring (310) of the present invention also has a raised structure. As shown in the third figure, the bottom surface (312) of the shielding ring (310) has bumps (313), the number of which can be at least three and evenly distributed on the bottom surface (312). The purpose of this design is to prevent the shielding ring (310) from colliding with the wafer or the substrate. The reason will be described in the subsequent paragraphs. The shape of the bump (313) in the figure is a hemispherical shape, but may be a cone shape in another embodiment. The bumps (313) and the shielding ring (310) can be made of the same material, such as alumina or aluminum nitride. Preferably, the bump (313) extends from the bottom surface (312) downward by 0.1 to 0.2 mm. The position of the bump (312) will only touch the other parts of the carrier disc, not the wafer, through proper selection.

The supporting element (320) has a top surface (321) and a bottom surface (322). The support element (320) is connected to the bottom surface (312) of the shielding ring (310) with a top surface (321). The bottom surface (322) of the support assembly (320) is configured to sit on the protrusion (235) of the processing chamber (20). Thereby, the shielding ring (310) is supported at a position above the protrusion (235), and the shielding ring (310) can be moved between the position and the top of the processing chamber. In one embodiment, the supporting element (320) is a ring body having a height (H). If the protrusion (235) is used as a reference point, the position of the shielding ring (310) can be determined by the height (H). In particular, the top surface (321) of the support assembly (320) of the present invention is connected to the bottom surface (312) of the shielding ring (310) via a detachable connection means. In this way, support elements with different heights can be used to change the position that the shielding ring (310) is intended to maintain. The choice of support element height (H) can be determined according to the processing position of the carrier plate. Proper height ensures that the gap between the mask ring and the wafer or substrate is sufficiently small. In one embodiment, the supporting element (320) is a ring body having a height. In other embodiments, the support element (320) may be composed of multiple independent elements.

The second image shows the position of the carrier disk (240) when it is not processed, and the third image shows the position of the carrier disk (240) when it is processed. Before the processing, the carrier tray (240) on which the wafer to be processed is placed is raised to a processing position, and a part of the carrier tray (240) is shielded by a shielding ring (310). At this time, a processing area is formed between the carrier plate (240), the shower element (211) and the side wall (230). The reaction gas enters the processing area from the shower head and is deposited on the wafer or the substrate, but is prevented from being deposited on the surrounding surface of the wafer due to the obstruction of the shielding ring (310).

According to the third figure, the fourth figure shows a partial enlarged view of the carrier tray (240) in the processing position. The carrier tray (240) stays in the processing position so that the upper surface of the wafer or substrate on the carrier tray (240) and the lower surface of the shielding ring (310) have a sufficiently small gap. However, for some reason, the processing position of the carrier tray (240) may be higher than expected. When the carrier tray (240) continues to rise, it will first contact the bumps (313) of the shielding ring (310), and drive the shielding device (30) to rise together. At this time, the wafer or the substrate maintains a minimum gap with the carrier plate (240) through the bumps (313). In one embodiment, the minimum gap is 0.1 to 0.2 mm. The height of the step structure (242) of the carrier plate (240) is appropriately configured, so that the step structure (242) can maintain a sufficient gap when it contacts the bump (313). As shown, the step structure (242) of the carrier tray may be slightly lower than the upper surface of the wafer or substrate. In some embodiments, the step structure may be higher than the upper surface of the wafer or substrate.

An advantage of the shielding device of the present invention is to ensure that the contact between the shielding ring and the bearing plate is a point contact, which can minimize the amount of particles generated by the collision between the shielding ring and the bearing plate (such as collision with a ceramic ring), and avoid Contaminated area. In addition, the support element of the present invention has a replaceable mechanism. Therefore, the gap between the shielding ring and the wafer can be determined by selecting the height of the supporting element.

The fifth figure illustrates that under the action of the shielding device of the present invention, even if there is a gap between the shielding ring and the wafer, the reactive gas is still effectively blocked and difficult to deposit on the edge of the wafer, thereby reducing the probability of the deposited film colliding with the surroundings. Generally, the gap between the shielding ring and the wafer is 0.3 to 0.5 mm, preferably 0.1 to 0.2 mm.

The sixth figure shows another embodiment (60) of the shielding device of the present invention, which includes a shielding ring (610) and a support assembly (620). The shielding ring (610) is similar to the aforementioned shielding ring and has a top surface, a bottom surface, and a tapered portion. In particular, the shielding ring (610) has a plurality of ears (611) that extend outward from the outside of the shielding ring (610). The figure shows three ears (611), which are evenly distributed on the shielding ring. Understandably, the radial size of the shielding ring (610) is smaller than the aforementioned shielding ring (310), so that the ear portion (611) is close to the inner wall of the processing cavity.

The support assembly (620) includes a plurality of support blocks (621), and is detachably mounted on the ears (611) of the shielding ring (610), respectively. The seventh figure shows the combination of the ear (611) and the support block (621). The supporting block (621) has a length (L), a width (W), and a height (H), wherein the length (L) and the height (H) define the supporting block (621) having a pair of joint surfaces (622). The supporting block (621) further has a coupling hole (623) extending between the coupling surfaces (622). The size of the coupling hole (623) is appropriately selected so that the ear (611) can be inserted without shaking and falling off. The combining hole may be a perforated hole or a blind hole.

The length (L) and width (W) of the support block (621) define an upper surface (unnumbered) and a lower surface (unnumbered). After installation, the shielding ring (610) is maintained at a height position between the upper surface and the lower surface of the support block (620), so that when the lower surface of the support block (620) contacts the protrusion (235) as shown in the second figure At this time, the shielding ring (610) is securely supported at a position in the processing cavity space. Support blocks of other heights can be provided for replacement, thereby adjusting the vertical position of the shielding ring in the cavity space. Understandably, the supporting blocks used must be consistent to maintain the shielding ring at a level. In other embodiments, the support block may include more than one coupling hole.

The eighth diagrams A to C show a set of mutually replaceable support blocks (820). These support blocks (820) have consistent length, width, and height, but the joint holes are located at different heights (H1, H2, H3). Thereby, at least three kinds of gaps between the aforementioned shielding ring (610) and the wafer or substrate to be processed can be selected. However, in other embodiments, the replaceable support blocks may have different length, width, and height.

The ninth figure shows a method of using the shielding device for a semiconductor processing chamber according to the present invention, wherein the processing chamber has a top, a bottom, a side wall, and a carrier tray capable of lifting and carrying a wafer as described above . The following steps can be described with reference to the aforementioned structural features. In step S901, one or more protrusions are provided, which extend from a side wall of the cavity. The side wall of the cavity may include an air suction ring having an inner wall, and the convex wall of the air suction ring extends. Step S902, a shielding device is provided, that is, the aforementioned shielding ring having a top surface and a bottom surface, the bottom surface of which is provided with a plurality of bumps, and the aforementioned supporting element having a top surface and a bottom surface, which are connected to the top surface by The bottom surface of the shielding ring contacts the protrusion in the processing cavity with the bottom surface, so that the entire supporting structure is maintained at a position in the cavity. In step S903, the carrier tray is raised until a gap is formed with the bottom surface of the shielding ring, and the inner edge of the shielding ring is located above a periphery of the wafer or substrate to be processed. When the carrier disk is higher than the expected position, the gap is formed by the bumps on the bottom surface of the shielding ring contacting the carrier disk. The method of the invention is not necessarily in the order described above.

Those skilled in the art will understand that many changes and modifications will become apparent. All such changes and modifications that a person skilled in the art should understand should fall within the broad spirit and scope of the invention described above.

10‧‧‧carriage tray

11‧‧‧ wafer

12‧‧‧ film

13‧‧‧step structure

20‧‧‧ treatment cavity

210‧‧‧Top

211‧‧‧Spray assembly

220‧‧‧ bottom

230‧‧‧ sidewall

231‧‧‧passage

232‧‧‧Exhaust ring

233‧‧‧Exhaust channel

234‧‧‧hole

235‧‧‧ protrusion

240‧‧‧carry tray

241‧‧‧Support shaft

242‧‧‧step structure

30‧‧‧shielding device

310‧‧‧shield ring

311‧‧‧Top

312‧‧‧ underside

313‧‧‧ bump

320‧‧‧ support assembly

321‧‧‧Top

322‧‧‧ underside

60‧‧‧shielding device

610‧‧‧Shield ring

611‧‧‧ear

620‧‧‧Support components

621‧‧‧ support block

622‧‧‧Combination surface

623‧‧‧Combination hole

H, H1, H2, H3‧‧‧ height

L‧‧‧ length

W‧‧‧Width

820‧‧‧Support block

S901-S903‧‧‧step

The first figure shows the wafer after the deposition process and the carrier tray (lacking the shielding device) supporting the wafer.

The second figure shows the processing chamber of the present invention and its shielding device (untreated position).

The third figure shows the processing chamber of the present invention and its shielding device (processing position).

The fourth figure is a partially enlarged view of the third figure, showing the shielding device of the present invention.

The fifth figure shows the wafer after the deposition process and the carrier tray supporting the wafer (using the shielding device of the present invention).

The sixth figure shows another embodiment of the shielding device of the present invention.

The seventh figure partially shows another embodiment of the shielding device of the present invention.

The eighth A through eight C diagrams show alternative elements of the present invention.

The ninth figure shows a method of using the shielding device of the present invention.

Claims (12)

A shielding device for a semiconductor processing cavity. The processing cavity has a side wall and a carrier plate. The shielding device includes: a shielding ring having a top surface and a bottom surface; A block for preventing the carrier disk from contacting the shielding ring; and a support element having a top surface and a bottom surface, the support element is connected to the shielding ring, and the bottom surface of the support element is configured to be in contact with the processing chamber One or more protrusions in the body contact, so that the shielding ring is supported at a position above the protrusions, and the shielding ring can be moved between the position and the top of the processing chamber. The shielding device according to item 1 of the patent application scope, wherein the thickness of the inner edge of the shielding ring is smaller than the thickness of the outer edge of the shielding ring. The shielding device according to item 1 of the patent application scope, wherein the plurality of bumps are spherical bumps or conical bumps. The shielding device according to item 1 of the patent application, wherein the top surface of the supporting element is connected to the bottom surface of the shielding ring via a detachable connection means. The shielding device according to item 1 of the scope of patent application, wherein the supporting element is a ring body, and the ring body has a height. The shielding device according to item 1 of the patent application scope, wherein a top surface of the supporting element is connected to a bottom surface of the shielding ring. The shielding device according to item 1 of the scope of patent application, wherein an outer side of the shielding ring has a plurality of ears, and the plurality of ears are connected to the supporting element. The shielding device according to item 7 of the scope of patent application, wherein the support element includes a plurality of support blocks, and each support block has a coupling hole for receiving the ear, so that the plurality of support blocks are respectively connected to the support block. Cover each ear of the ring. A method for using a shielding device for a semiconductor processing chamber, wherein the processing chamber has a side wall and a carrier tray capable of lifting and carrying a wafer, and the method includes: providing one or more protrusions, The protruding portion extends from the side wall; a shielding device is provided, including: a shielding ring having a top surface and a bottom surface, the bottom surface of the shielding ring having a plurality of bumps; and a supporting element having a top surface and A bottom surface, the supporting element is connected to the shielding ring, and the bottom surface of the supporting element is configured to contact one or more protruding portions in the processing cavity, so that the shielding ring is supported on the protruding portion; An upper position; and raising the carrier plate until a gap is formed between the carrier plate and the bottom surface of the shielding ring, so that the inner edge of the shielding ring is located above a periphery of the wafer. The method according to item 9 of the scope of the patent application, wherein the gap is formed by the plurality of bumps on the bottom surface of the shielding ring contacting the carrier disk. The method according to item 10 of the application, wherein a top of the carrier disk has a ceramic ring, and the gap is formed by the plurality of bumps on the bottom surface of the shielding ring contacting the ceramic ring of the carrier disk. The method according to item 9 of the scope of the patent application, wherein the side wall of the processing chamber includes an extraction ring, the extraction ring has an inner wall, and the protrusion extends from the inner wall of the extraction ring.