CN-122013154-A - PECVD chamber backboard

CN122013154ACN 122013154 ACN122013154 ACN 122013154ACN-122013154-A

Abstract

The invention discloses a PECVD chamber backboard, which relates to the technical field of semiconductor manufacturing equipment and comprises a substrate, a plurality of gas diversion mechanisms, a driving mechanism and a plurality of control units, wherein the upper surface of the substrate is provided with an air inlet, the gas diversion mechanisms are rotatably arranged on the lower surface of the substrate and distributed along the circumferential direction of the substrate, the gas diversion mechanisms are provided with two gas flow channel structures, namely an air outlet and an air outlet, and the driving mechanism is arranged on the substrate and is used for driving the gas diversion mechanisms to synchronously rotate so as to switch different gas flow channel structures to working positions. According to the invention, by arranging the rotatable air diversion mechanism, two air flow channel structures are integrated on the same backboard. The deposition stage is switched to a micropore exhaust mode to realize low-pressure laminar flow uniform air injection and ensure the consistency of the thickness of the film, and the cleaning stage is switched to a wide-groove exhaust mode to generate high-kinetic-energy scouring air flow. The structural design enables different requirements of the deposition process and the cleaning process on the flow field to be combined on the same hardware.

Inventors

QUAN LONGZHE
QUAN XIUJUAN
LI DONGQIN
JIN YONGSHAN
Han Dongri
JIN CHUNJUN

Assignees

爱极宝电子工业设备(广州)有限公司

Dates

Publication Date: 20260512
Application Date: 20260410

Claims (11)

1. A PECVD chamber back plate, comprising: The device comprises a base plate (1), wherein an air inlet hole (21) is formed in the upper surface of the base plate (1); The gas distribution mechanisms (3) are rotatably arranged on the lower surface of the base plate (1) and distributed along the circumferential direction of the base plate (1), the gas distribution mechanisms (3) are provided with two gas flow channel structures, and the gas inlet holes (21) are communicated with the gas distribution mechanisms (3) to realize gas transmission; The driving mechanism is arranged on the base plate (1) and is used for driving the plurality of air distribution mechanisms (3) to synchronously rotate so as to switch different air flow channel structures to working positions.
2. The PECVD chamber backing plate of claim 1, wherein the gas diverting mechanism (3) comprises: A diversion cylinder (31) rotatably and internally mounted on the lower surface of the base plate (1); At least two groups of exhaust holes (32) are formed in the side wall of the flow dividing barrel (31), each group of exhaust holes (32) are distributed at intervals along the circumferential direction of the flow dividing barrel (31), and each group of exhaust holes (32) has different aperture specifications and is used for providing different airflow injection modes in a deposition stage.
3. The PECVD chamber back plate of claim 2, wherein the sidewall of the diverter cylinder (31) is further provided with a vent slot (33), the vent slot (33) extending axially of the diverter cylinder (31) for providing high throughput gas flow injection during the cleaning phase.
4. A PECVD chamber back plate according to claim 3, wherein both ends of the shunt tube (31) are fixedly connected with external connection tubes (35), and air rotary joints (36) are arranged at the ends of both external connection tubes (35); The inside of the base plate (1) is provided with a first gas transmission pipeline (23) communicated with the gas inlet hole (21), the inside of the base plate (1) is provided with a first annular inner hole (43), the first annular inner hole (43) is communicated with a second gas transmission pipeline (44), the upper side of the first annular inner hole (43) is communicated with a first gas transmission pore channel (42), and a first gas joint (41) is arranged on the upper side of the first gas transmission pore channel (42); The first air conveying pipeline (23) and the second air conveying pipeline (44) are respectively connected with the cyclone adapter (36) positioned on the inner side and the outer side.
5. A PECVD chamber back plate according to claim 3, wherein a plurality of flow dividing plates (34) are fixed in the exhaust groove (33) for changing the jetting direction of the cleaning gas, the plurality of flow dividing plates (34) are distributed along the axial direction of the flow dividing cylinder (31), and the flow dividing plates (34) positioned in the middle are perpendicular to the surface of the flow dividing cylinder (31), and the inclined angles of the flow dividing plates (34) extending towards the two ends are gradually increased relative to the normal line of the flow dividing cylinder (31).
6. The back plate of the PECVD chamber according to claim 4, wherein the two external pipes (35) are internally and integrally provided with one-way valves (37), and the opening directions of the two one-way valves (37) face the inner cavity of the split cylinder (31).
7. A PECVD chamber back plate according to claim 3, wherein the lower surface of the base plate (1) is provided with a mounting groove matched with the diversion cylinder (31), the two sides of the lower edge of the mounting groove are provided with chamfer grooves, and the chamfer grooves are internally provided with expandable and contractible sealing elastic bags; the sealing elastic bladder is in communication with an external air pressure control source for expanding during the deposition phase to seal the gap between the diverter cartridge (31) and the mounting groove and contracting during the purge phase to release the space.
8. The PECVD chamber back plate according to claim 7, wherein the sealing elastic bladder comprises a lateral portion parallel to the bottom of the substrate (1), and an arc portion (68) connected to one side of the lateral portion near the shunt barrel (31); A rigid partition plate (66) is arranged in the middle of the transverse part, and two sides of the transverse part are separated into a first flexible parting strip (65) and a second flexible parting strip (67); a notch groove (69) is formed in the surface of one side, close to the diversion barrel (31), of the arc-shaped part (68).
9. The PECVD chamber back plate of claim 1, wherein the drive mechanism comprises: a gear (52) fixed to a plurality of the gas diversion mechanisms (3); A rack (51) engaged with the gear (52); a wire rope (53) connecting adjacent racks (51); The linear driver (54) is fixed on the base plate (1), and the telescopic end of the linear driver (54) is fixedly connected with one of the steel wire ropes (53) through a connecting vertical rod (55); When the linear driver (54) stretches, the steel wire rope (53) drives the racks (51) to synchronously displace, so that the gas distribution mechanisms (3) are driven to synchronously rotate.
10. The back plate of the PECVD chamber according to claim 1, wherein a conical hole (22) is formed in the middle of the lower surface of the substrate (1), the conical hole (22) and the air inlet hole (21) are coaxially arranged and are mutually communicated, and the conical hole (22) is in a longitudinal section structure with a narrow upper part and a wide lower part and is used for guiding the entering air flow to decompress along the conical surface and diffuse to the periphery.
11. A flow field regulating method using the PECVD chamber back plate according to any one of claims 1-10, comprising the steps of: s1, controlling a driving mechanism to drive a plurality of gas diversion mechanisms to synchronously rotate to working positions of a deposition stage, so that exhaust holes of the gas diversion mechanisms are in a working state; S2, introducing deposition gas into the air inlet hole, and discharging the deposition gas into the process cavity through the air outlet hole to form an air flow field required by a deposition process; s3, stopping introducing deposition gas after the deposition process is completed, and controlling the driving mechanism to drive the plurality of gas diversion mechanisms to synchronously rotate to working positions of the cleaning stage so that the exhaust grooves of the gas diversion mechanisms are in a working state; s4, introducing cleaning gas into the gas diversion mechanism, and discharging the cleaning gas into the process cavity through the exhaust hole to form an airflow field required by the cleaning process; And S5, in the cleaning process, controlling the driving mechanism to drive the plurality of gas diversion mechanisms to swing back and forth within a preset angle range so as to dynamically adjust the spraying direction of the cleaning gas.

Description

PECVD chamber backboard Technical Field The invention relates to the technical field of semiconductor manufacturing equipment, in particular to a PECVD chamber backboard. Background PECVD (plasma enhanced chemical vapor deposition) technology is a core process means in the fields of semiconductor, panel display and photovoltaic manufacture, and is mainly used for depositing various functional films such as silicon nitride, silicon oxide and the like on the surface of a substrate. A Backing Plate is a key component of the PECVD process chamber, located between the gas inlet and the Diffuser, and serves as a core for supporting the chamber structure, carrying the electrode pressure, and precisely distributing the process gases. In prior art solutions, the back plate is typically formed with an air flow path by machining (e.g., gun drilling, inclined hole machining) or by nesting the tubes. In order to improve uniformity of gas distribution, the prior art mostly adopts a gradient aperture design or adds a flow dividing mechanism at the center of the back plate, so as to shorten time for diffusing process gas from a central gas inlet to four corners of a chamber, thereby improving consistency of film formation to a certain extent and reducing initial waste of gas. However, research and production practices have shown that current PECVD chamber backplanes still face significant compatibility challenges in flow field control. For example, korean patent No. 10-2025-0010693, entitled back plate and substrate processing apparatus mounted thereon, as shown in fig. 1, in the structure of the back plate, the deposition stage and the gas distribution spray holes (gas flow channels) used in the cleaning stage are completely identical and the physical structure is fixed. However, in the actual process flow, there is a substantial difference in the requirements of the flow field in the two stages, that is, in the deposition stage, in order to ensure high uniformity of the thickness of the nano-scale thin film, the gas flow is required to be vertically sprayed to the substrate in a uniform laminar flow shape at a stable pressure and a low speed, and in the plasma cleaning stage (usually using etching gas), the process targets are to quickly and thoroughly remove accumulated byproducts at the edges of the chamber, the back surface of the diffuser and the dead angle of the support, which requires a very high flow rate, a strong kinetic energy scouring capability of the gas flow, and a rotating flow field or a large-angle spraying vector capable of covering the edge region. Because the pore structure of the existing backboard cannot be dynamically adjusted, if the pore diameter is reduced to meet the deposition uniformity, the air flow is limited in the cleaning stage, the dead zone at the edge cannot be flushed in place, the cleaning time is greatly prolonged, and expensive cleaning gas is wasted, otherwise, if the flow field direction is changed to improve the cleaning efficiency, the laminar flow stability in the deposition stage is damaged, and the film forming quality is reduced. Disclosure of Invention The invention aims to provide a PECVD chamber backboard, which solves the problem that laminar flow uniformity in a deposition stage and strong flushing requirements in a cleaning stage are mutually contradictory due to the fixed structure of the existing backboard, overcomes cleaning dead angles and gas waste caused by unadjustable flow field vectors, and realizes self-adaptive switching and efficient matching of flow fields in different process stages. The invention solves the technical problems through the following technical scheme that the invention comprises a base plate, wherein the upper surface of the base plate is provided with an air inlet hole; the gas diversion mechanisms are rotatably arranged on the lower surface of the base plate and distributed along the circumferential direction of the base plate, and the gas diversion mechanisms are provided with two gas flow channel structures, namely exhaust holes and exhaust grooves; the driving mechanism is arranged on the substrate and used for driving the plurality of air distribution mechanisms to synchronously rotate so as to switch different air flow channel structures to working positions. Preferably, the gas diversion mechanism comprises: The shunt barrel is rotatably and internally embedded on the lower surface of the base plate; At least two groups of exhaust holes are formed in the side wall of the flow distribution cylinder, each group of exhaust holes are distributed at intervals along the circumferential direction of the flow distribution cylinder, and each group of exhaust holes have different aperture specifications and are used for providing different airflow injection modes in a deposition stage. Preferably, the side wall of the diversion barrel is further provided with an exhaust groove, and the exhaust groove extends along the axial direction of th