TW202303820A - Silicon wafer substrate conveying device and method for improving flatness of epitaxial wafer - Google Patents

Abstract

The embodiment of the invention discloses a silicon wafer substrate conveying device and method for improving the flatness of an epitaxial wafer, the conveying device is arranged in a process chamber of epitaxial deposition equipment, and the conveying device comprises a heating module, a control module and a transmission module, the heating module is configured to radiate heat to a silicon wafer at different heating powers in the process that the silicon wafer reaches a processing position in the process chamber from the outside of the process chamber; and the conveying module is configured to convey the silicon wafer to the processing position at different movement speeds according to the position of the silicon wafer after the silicon wafer enters the process chamber. The speed of the substrate silicon wafer at each position is adjusted through the conveying module, and the power ratio of the heating lamp group at each stage is adjusted through the heating module in the process that the silicon wafer enters the process chamber, so that the influence of the temperature difference on the quality of the epitaxial wafer on the substrate is reduced.

Description

A silicon substrate transfer device and method for improving epitaxial wafer flatness

Embodiments of the present invention belong to the technical field of epitaxial wafer manufacturing, and in particular relate to a silicon wafer substrate transfer device and method for improving the flatness of epitaxial wafers.

In the field of semiconductors, silicon wafers are generally the raw material for integrated circuits. Among them, epitaxial wafers are widely used in highly integrated integrated circuit (Integrated Circuit, IC) components and Metal-Oxide-Semiconductor (Metal-Oxide-Semiconductor, MOS) processes due to their few surface defects and controllable resistivity. . Circuits and electronic components need to be fabricated on epitaxial wafers. Different applications such as P-type metal oxide semiconductor (Positive channel-Metal-Oxide-Semiconductor, PMOS) and N-type metal oxide semiconductor (Negative channel-Metal-Oxide-Semiconductor) in MOS type -Semiconductor, NMOS), complementary metal-oxide-semiconductor (Complementary Metal-Oxide-Semiconductor, CMOS) and bipolar in saturated and unsaturated types. With the development trend of integrated circuit design towards light, thin, short, small and power-saving, products such as mobile communications and information appliances are all striving to save energy consumption, and the requirements for epitaxial wafer products are also increasing.

At present, the most widely used method for epitaxial silicon wafers is atmospheric pressure epitaxial deposition. Since epitaxial wafers grow an epitaxial layer on the surface of polished wafers through vapor deposition reaction, the quality of the substrate is very important to the quality of epitaxial wafers. influencing factors.

In view of this, embodiments of the present invention expect to provide a silicon wafer substrate transfer device and method for improving the flatness of epitaxial wafers; when manufacturing epitaxial wafers, during the process of loading the substrate to the processing position, by adjusting The speed of the axis at each position and the power ratio of the heating lamp group at each stage of the epitaxial wafer entering the deposition chamber improve the quality of the substrate.

The technical scheme of the embodiment of the present invention is realized like this: In a first aspect, an embodiment of the present invention provides a silicon wafer substrate transfer device for improving the flatness of an epitaxial wafer. The transfer device is arranged in a reaction chamber of an epitaxial deposition device, and the transfer device includes: a heating module, the heating module is configured to radiate heat to the silicon wafer with different heating powers during the process from the outside of the reaction chamber to the processing position in the reaction chamber; the transport module, the The conveying module is configured to convey the silicon wafer to the processing position at different moving speeds according to the position of the silicon wafer after the silicon wafer enters the reaction chamber.

In the second aspect, an embodiment of the present invention provides a method for transferring a silicon wafer substrate to improve the flatness of an epitaxial wafer. The method for transferring includes: When the wafer is outside the reaction chamber, adjust the power ratio of the second heating unit to be higher than that of the first heating unit so that the tray heats up rapidly; when the wafer enters the reaction chamber until the tray is loaded onto the wafer , adjust the power ratio of the first heating unit to be higher than that of the second heating unit so that the temperature of the wafer reaches the temperature of the reaction chamber quickly; when the tray is loaded on the wafer, raise the heating module The total power to complete the processing of the silicon wafer. Wherein, the process of the silicon wafer entering the reaction chamber until the tray is loaded onto the silicon wafer specifically includes: After the silicon wafer enters the reaction chamber, the support rod passes through the tray so that the support rod can contact the silicon wafer before the tray, and the support rod and the tray are driven to rise synchronously; when the support rod is about to contact the silicon wafer When the support rod and the tray are lowered so that the support rod slowly supports the silicon wafer; when the support rod supports the silicon wafer, the support rod carries the silicon wafer and continues to rise synchronously with the tray until the support rod supports the wafer. rod reaches the highest position; after the support rod reaches the highest position, the support rod stops moving, and the tray continues to rise until the tray carries the silicon wafer; when the tray carries the silicon wafer, increase the lifting speed of the tray and move the The silicon wafer is transferred to the processing position.

Embodiments of the present invention provide a silicon wafer substrate transfer device and method for improving the flatness of epitaxial wafers. When manufacturing epitaxial wafers, during the process of loading the substrate to the processing position, by adjusting The speed and the power ratio of the heating unit at each stage of the epitaxial wafer entering the reaction chamber can minimize the deformation of the epitaxial wafer substrate at each stage of entering the chamber, improve the quality of the substrate, and thus improve the flatness of the epitaxial wafer (Bow/ Warp) and particle defects, etc., to improve the quality of epitaxial wafer products.

In order for Ligui examiners to understand the technical characteristics, content and advantages of the present invention and the effects it can achieve, the present invention is hereby combined with the accompanying drawings and appendices, and is described in detail in the form of embodiments as follows, and the drawings used therein , the purpose of which is only for illustration and auxiliary instructions, and not necessarily the true proportion and precise configuration of the present invention after implementation, so it should not be interpreted based on the proportion and configuration relationship of the attached drawings, and limit the application of the present invention in actual implementation The scope is described first.

In the description of the embodiments of the present invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical" , "horizontal", "top", "bottom", "inner", "outer" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description , rather than indicating or implying that the device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and thus should not be construed as limiting the invention.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of said features. In the description of the embodiments of the present invention, "plurality" means two or more, unless otherwise specifically defined.

In the embodiments of the present invention, terms such as "installation", "connection", "connection" and "fixation" should be interpreted in a broad sense unless otherwise clearly specified and limited. Disassembled connection, or integration; it can be mechanical connection or electrical connection; it can be direct connection or indirect connection through an intermediary, and it can be the internal communication of two components or the interaction relationship between two components. Those with ordinary knowledge in the art can understand the specific meanings of the above terms in the embodiments of the present invention according to specific situations.

The following will clearly and completely describe the technical solutions in the embodiments of the present invention in combination with the drawings in the embodiments of the present invention.

Referring to FIG. 1 , it shows a schematic diagram of a transmission path of an epitaxial deposition device 10 commonly used in the related art. The epitaxial deposition device 10 includes: a silicon wafer loading port 1 , an interaction unit 2 (FI), a pre-evacuation chamber 3 (Loadlock), a buffer chamber 4 and a reaction chamber 5 . Generally, the epitaxial deposition device 10 may include one or more pre-evacuated chambers 3, which are used to suck the substrate entering the epitaxial deposition device 10, and transport the substrate in the pre-evacuated chamber 3 to the reaction chamber by a robot arm or other transfer device room for processing. During the entire transfer process of the substrate, the temperature of the reaction chamber 5 is very high, while the other chambers are maintained at normal temperature. When the silicon wafer enters and exits the reaction chamber 5 due to a sudden change in temperature, the substrate silicon wafer will be damaged. Deformation will affect subsequent processing.

Wherein, the entire reaction chamber 5 is heated by an external halogen lamp, which provides the heat required by the chemical reaction in the reaction chamber 5 through thermal radiation. The silicon wafer on the substrate is always at normal temperature before entering the reaction chamber 5. However, the temperature in the reaction chamber is about 600-700 degrees Celsius. The sharp temperature change will cause the silicon wafer to deform during the transmission process. In addition to the local deformation of the part contacted by the tools used to transport the silicon wafer, the position of the silicon wafer will also shift due to contact collision during the transmission process. At this time, the back of the silicon wafer, that is, the silicon wafer and the used The tool that transports the silicon wafer creates friction, which forms particles in the reaction chamber. In addition, during the subsequent processing, the position where the silicon wafer falls into the tool used to transport the silicon wafer will also be skewed, causing quality problems such as flatness, slip lines, and particles of the epitaxial wafer.

Therefore, in view of the above-mentioned technical problems, the present invention proposes a silicon wafer substrate transfer device that improves the flatness of epitaxial wafers. quality of silicon wafers. Referring to FIG. 2 , it shows a silicon substrate conveying device for improving the flatness of epitaxial wafers according to an embodiment of the present invention, the conveying device includes a heating module 6 and a conveying module 7 .

The transport module 7 is used to transport the silicon wafers entering the reaction chamber to a predetermined location for processing. By improving the transport speed, the silicon wafers are fully heated during the transport process and reduce the friction and friction that may occur during contact. . The delivery module 7 includes a tray 71 and a tray support shaft 72. The tray 71 is used to carry silicon wafers to be processed. The tray support shaft 72 is used to drive the tray 71 to lift and rotate. The tray 71 can be driven up by the tray support shaft 72. To carry the silicon wafer and continue to rise to transfer the silicon wafer to the predetermined position for processing. Further, the transport module 7 also includes a support rod 73 and a support rod support shaft 74, and the support rod support shaft 74 drives the support rod 73 to rise. The supporting rods 73 are configured to pass through the tray 71 and contact the silicon wafer preferentially, and the surface of the tray 71 is uniformly provided with a plurality of through holes through which the supporting rods 73 can pass. Through the above structure, the tray support shaft 72 and the support rod support shaft 74 respectively drive the tray 71 and the support rod 73 to rise to meet the silicon wafer. During the rising process, the speed of the tray 71 and the support rod 73 is always consistent. , the support rod 73 is first in contact with the silicon wafer, the support rod 73 supports the silicon wafer, the tray 71 and the support rod 73 continue to rise synchronously, until the support rod 73 reaches the highest position, the support rod 73 stops rising, and the tray 71 continues to rise so that the tray The upper surface of the tray 71 is in contact with the bottom surface of the silicon wafer, so that the tray 71 completely carries the silicon wafer. During this process, the transport module 7 passes through a speed controller (not shown) to ensure that the contact part between the support rod 73 and the silicon wafer will not be partially deformed, and the support rod 73 will not rub against the bottom surface of the silicon wafer and the silicon wafer and the tray 71. The position on the surface does not shift and other problems, thereby ensuring the quality of the substrate silicon wafer and improving the quality of the epitaxial wafer. Through the speed controller, the stable contact between the support rod 73 and the silicon wafer, and the tray 71 and the silicon wafer is realized. The speed controller controls the support rod support shaft 74 and the tray support shaft 72 through the motor to adjust the ascending speed of the support rod 73 and the pallet 71 . Further, whenever the support rod 73 rises to contact the silicon wafer to support the silicon wafer or whenever the tray 71 rises to contact the silicon wafer to carry the silicon wafer, the rising speed of the support rod 73 and the tray 71 is reduced to reduce the impact due to mechanical impact. damage caused. In addition, through the speed controller, the rising speed of the tray 71 and the supporting rod 73 can be adjusted separately, which can prolong the heating time of the silicon wafer.

The heating module 6 is used to radiate heat to the silicon wafer in the reaction chamber, and by improving the power ratio of the heating module, the temperature of the silicon wafer is as uniform as possible. The heating module 6 includes a first heating unit 61 arranged above the tray and a second heating unit 62 arranged below the tray 71, the first heating unit 61 directly radiates heat to the upper surface of the silicon wafer, and the second heating unit 62 The heat conduction through the tray 71 transfers the hot spot to the lower surface of the silicon wafer. The first heating unit 61 and the second heating unit 62 are composed of two or more halogen lamps. The first heating unit 61 is configured to provide heat to the central part and the outer part of the silicon wafer respectively by different halogen lamps. The heating unit 62 is the same. Since the lower surface of the silicon chip conducts heat through the tray 71, the temperature distribution on the upper and lower surfaces of the silicon chip is uneven. In order to make the temperature of the silicon chip as consistent as possible, the heating module 6 also includes a temperature controller and a temperature sensor, and the temperature sensor is used to monitor the temperature of the upper surface of the silicon chip and the temperature of the lower surface of the silicon chip. The temperature of the lower surface of the tray 71 is monitored to characterize the temperature of the lower surface of the silicon wafer. Referring to Fig. 2, the first heating unit 61 and the second heating unit 62 are heated up and down at the same time, and the heating module 6 controls the power ratio of the first heating unit 61 and the second heating unit 62 through the temperature controller, so that the upper and lower surfaces of the silicon wafer Even temperature. The temperature controller is configured to: before the silicon wafer enters the reaction chamber, adjust the power of the second heating unit to be greater than that of the first heating unit, so that the tray 71 heats up rapidly; when the silicon wafer enters the reaction chamber and is not carried by the tray 71, Increase the power ratio of the first heating unit; when the silicon chip is loaded on the tray 71, adjust the power ratio between the first heating unit and the second heating unit, and use the tray with a higher temperature for rapid heat conduction and the second one with a higher power ratio. A heating unit makes the silicon wafer quickly reach the temperature of the reaction chamber, thereby reducing the amount of deformation caused by the temperature. It should be noted that when adjusting the power ratio to adjust the temperature, excessive adjustment will lead to uneven heating of the upper and lower surfaces of the silicon wafer, greater deformation or other defects such as slip lines.

The wafer substrate conveying device for improving the flatness of the epitaxial wafer shown in Figure 2 is used to monitor the temperature of the upper and lower surfaces of the wafer through the temperature sensor during the process of receiving the wafer from the outside and transferring the wafer to the predetermined position, and according to the monitoring The obtained temperature value is controlled by the temperature controller to control the first heating unit and the second heating unit to radiate heat to the upper surface and the lower surface of the silicon wafer at different stages with different powers, so that the temperature of the upper and lower surfaces of the silicon wafer is uniform. At the same time, after the silicon wafer enters the reaction chamber, the transfer device controls the speed of the contact between the tray and the support rod and the silicon wafer through the transport module to avoid damage caused by mechanical movement, and adjust the moving speed of the tray as needed to prolong the heating of the silicon wafer time. Referring to FIG. 3 , it shows a silicon substrate transfer method for improving the flatness of an epitaxial wafer provided by an embodiment of the present invention. The transfer method can be applied to the transfer device shown in FIG. 2 , and the transfer method includes the following steps: S301: When the silicon wafer is located outside the reaction chamber, adjust the power ratio of the second heating unit to be higher than that of the first heating unit so as to rapidly heat up the tray; S302: During the process of the silicon wafer entering the reaction chamber until the tray is loaded on the silicon wafer, adjusting the power ratio of the first heating unit to be higher than that of the second heating unit so that the temperature of the silicon wafer quickly reaches the temperature of the reaction chamber; S303: After the tray is loaded on the silicon wafer, increase the total power of the heating module to complete the processing of the silicon wafer.

In an example, the silicon wafer substrate transfer method for improving the flatness of the epitaxial wafer provided by the embodiment of the present invention can be carried out according to the following parameters: when the silicon wafer is located outside the reaction chamber, the power of the second heating unit is adjusted to 58%, The power of the second heating unit for heating the central part of the silicon wafer is adjusted to 12.5%, and the power of the first heating unit for heating the central part of the silicon wafer is adjusted to 52%; after the silicon wafer enters the reaction chamber until the tray is loaded on the silicon wafer During the process, the power of the second heating unit is adjusted to 60%, the power of the second heating unit for heating the central part of the silicon wafer is adjusted to 14.5%, and the power of the first heating unit for heating the central part of the silicon wafer is adjusted to 70%. ;When the tray is loaded on the silicon wafer, the power of the second heating unit is adjusted to 50%, the power of the second heating unit for heating the central part of the silicon wafer is adjusted to 15%, and the first heating unit is used for heating the central part of the silicon wafer power adjustment to 60%.

Through the technical solution shown in FIG. 3 , in the embodiment of the present invention, the power of the first heating unit and the second heating unit can be respectively adjusted to ensure uniform temperature on the upper and lower surfaces of the silicon wafer. In order to further improve the quality of the substrate silicon wafer, since the silicon wafer is transported by a mechanical device during the process of the silicon wafer entering the reaction chamber until the tray is loaded on the wafer, it is easy to be damaged by mechanical collision and affect the epitaxial structure. In order to solve this technical problem, referring to Figure 4, the process of the silicon wafer entering the reaction chamber until the tray is loaded onto the silicon wafer specifically includes: S401: After the silicon wafer enters the reaction chamber, the support rod passes through the tray so that the support rod can contact the silicon wafer before the tray, and drives the support rod and the tray to rise synchronously; S402: When the support rod is about to contact the silicon wafer, reduce the lifting speed of the support rod and the tray so that the support rod slowly supports the silicon wafer; S403: After the supporting rod supports the silicon wafer, the supporting rod carries the silicon wafer and continues to rise synchronously with the tray until the supporting rod reaches the highest position; S404: After the support rod reaches the highest position, the support rod stops moving, and the tray continues to rise until the tray carries the silicon wafer; S405: After the tray carries the silicon wafer, increase the lifting speed of the tray and transfer the silicon wafer to a processing position.

Through the technical solution shown in Figure 4, the embodiment of the present invention can respectively drive the support rod and the tray to rise through the support rod support shaft and the tray support shaft, and reduce the speed of the support rod or the tray when the support rod or the tray touches the silicon wafer to ensure The supporting rods or trays are in slow contact with the silicon wafers, avoiding damage caused by the contact of the mechanical structure, and further improving the quality of the substrate silicon wafers.

Therefore, the present invention provides a silicon wafer substrate conveying device for improving the flatness of epitaxial wafers. The power ratio of the heating unit at each stage of the wafer entering the reaction chamber can minimize the deformation of the epitaxial wafer substrate at each stage of entering the chamber, improve the quality of the substrate, thereby improving the flatness and particle defects of the epitaxial wafer, and improving Epitaxial wafer product quality.

It should be noted that: the technical solutions described in the embodiments of the present invention can be combined arbitrarily if there is no conflict.

The above are only preferred embodiments of the present invention, and are not used to limit the implementation scope of the present invention. If the present invention is modified or equivalently replaced without departing from the spirit and scope of the present invention, it shall be covered by the protection of the patent scope of the present invention. in the range.

1: Silicon load port 2: Interactive unit 3: Pre-evacuation chamber 4: buffer chamber 5: Reaction chamber 6: Heating module 7: Shipping Module 10: Epitaxial deposition device 61: The first heating unit 62: Second heating unit 71: tray 72: Pallet support shaft 73: support rod 74: support rod support shaft S301-S303: Steps S401-S405: Steps

1 is a schematic diagram of an atmospheric pressure epitaxial deposition device in the related art; FIG. 2 is a schematic diagram of a silicon substrate transfer device for improving the flatness of epitaxial wafers provided by an embodiment of the present invention; FIG. 3 is a schematic flow diagram of a silicon substrate transfer method for improving the flatness of epitaxial wafers provided by an embodiment of the present invention; FIG. 4 is a schematic flowchart of the process from the silicon wafer entering the reaction chamber until the tray is loaded onto the silicon wafer in a silicon wafer substrate transfer method for improving the flatness of the epitaxial wafer provided by an embodiment of the present invention.

6: Heating module

7: Shipping Module

61: The first heating unit

62: Second heating unit

71: tray

72: Pallet support shaft

73: support rod

74: support rod support shaft

Claims (10)

A silicon substrate transfer device for improving the flatness of epitaxial wafers, the transfer device is arranged in the reaction chamber of epitaxial deposition equipment, the transfer device includes: a heating module configured to radiate heat to the silicon wafer at different heating powers during the process of the silicon wafer reaching a processing position in the reaction chamber from outside the reaction chamber; The transport module is configured to transport the silicon wafer to the processing position at different moving speeds according to the position of the silicon wafer after the silicon wafer enters the reaction chamber. The silicon substrate conveying device for improving the flatness of epitaxial wafers according to claim 1, wherein the conveying module includes a tray for carrying the silicon wafer and a tray support shaft for driving the tray to lift and rotate. The silicon wafer substrate transfer device for improving the flatness of epitaxial wafers according to claim 2, wherein the transport module further includes a support rod and a support rod support shaft for driving the support rod to move up and down, and the support rod is configured as passing through the tray to support the wafer prior to the tray. The silicon wafer substrate conveying device for improving the flatness of epitaxial wafers according to claim 3, wherein the conveying module further includes a speed controller configured to control the speed of the tray support shaft and the support rod support shaft speed of movement. The silicon substrate conveying device for improving the flatness of epitaxial wafers according to claim 4, wherein the speed controller realizes the movement speed control of the tray support shaft and the support rod support shaft through motor adjustment. The silicon substrate transfer device for improving the flatness of epitaxial wafers according to claim 2, wherein the heating module includes a first heating unit arranged above the tray and a second heating unit arranged below the tray. The silicon substrate transfer device for improving the flatness of epitaxial wafers as described in claim 6, wherein the heating module further includes a temperature controller and a temperature sensor, and the temperature sensor is configured to monitor and give feedback to the temperature controller The temperature of the upper surface of the wafer and the temperature of the lower surface of the tray, the temperature controller is configured to adjust the first heating unit and the second heating unit respectively according to the temperature of the upper surface of the silicon wafer and the temperature of the lower surface of the tray power ratio. The silicon substrate transfer device for improving the flatness of epitaxial wafers according to claim 6, wherein the first heating unit and the second heating unit are composed of two or more halogen lamps. A silicon wafer substrate transfer method for improving the flatness of epitaxial wafers, the transfer method is applied to the silicon wafer substrate transfer device for improving the flatness of epitaxial wafers according to any one of claims 1 to 8, the transfer method includes: When the silicon wafer is located outside the reaction chamber, the power ratio of the second heating unit is adjusted to be higher than that of the first heating unit so that the tray heats up rapidly; When the silicon wafer enters the reaction chamber until the tray is loaded onto the silicon wafer, the power ratio of the first heating unit is adjusted to be higher than that of the second heating unit so that the temperature of the silicon wafer reaches the reaction chamber quickly room temperature; After the tray is loaded on the silicon wafer, the total power of the heating module is increased to complete the processing of the silicon wafer. The silicon wafer substrate transfer method for improving the flatness of the epitaxial wafer as described in Claim 9, wherein the process of the silicon wafer entering the reaction chamber until the tray is loaded onto the silicon wafer specifically includes: After the silicon wafer enters the reaction chamber, the support rod passes through the tray so that the support rod can contact the silicon wafer prior to the tray, driving the support rod and the tray to rise synchronously; When the support rod is about to contact the silicon wafer, reducing the lifting speed of the support rod and the tray so that the support rod slowly supports the silicon wafer; After the supporting rod supports the silicon wafer, the supporting rod carries the silicon wafer and continues to rise synchronously with the tray until the supporting rod reaches the highest position; After the support rod reaches the highest position, the support rod stops moving, and the tray continues to rise until the tray carries the silicon wafer; After the tray carries the silicon wafer, the lifting speed of the tray is increased and the silicon wafer is transferred to the processing position.

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