TWI837805B - A carrying device and equipment for cleaning silicon wafers and silicon wafers - Google Patents

Abstract

The embodiment of the present invention discloses a supporting device, equipment and silicon wafer for cleaning silicon wafers; the supporting device includes a supporting frame composed of multiple supporting rods for supporting silicon wafers; each supporting rod includes: multiple slots for inserting silicon wafers; multiple grooves evenly distributed in the circumferential direction on the opposite sides of the slots, allowing cleaning liquid to flow in the grooves.

Description

A carrier device, equipment and silicon wafer for cleaning silicon wafer

The present invention relates to the field of semiconductor technology, and more particularly to a carrier, equipment and silicon wafer for cleaning silicon wafers.

Usually, after a series of production steps such as cutting, grinding, polishing, and epitaxial growth, single crystal silicon rods are produced to obtain silicon wafers used in the manufacture of semiconductor devices. During the above production steps, various foreign matters such as particulate contaminants and metal ion impurities are easily generated due to reasons such as the silicon wafer itself or the external environment. These particulate contaminants and metal ion impurities will contaminate the silicon wafer, thereby reducing the production yield of semiconductor devices. Therefore, in order to completely remove these foreign matters, it is necessary to use a cleaning device to clean and rinse the silicon wafer. During the silicon wafer cleaning process, the silicon wafer carrier is one of the main tools of the cleaning device. The structure of the carrier directly affects the cleaning quality of the silicon wafer. However, due to the unreasonable structural design of the silicon wafer carrier in the related technology, the above-mentioned foreign matter still exists on the surface of the silicon wafer after cleaning.

In view of this, the embodiments of the present invention are intended to provide a carrier, equipment and silicon wafer for cleaning silicon wafers; the pollutants remaining on the supporting rods in the carrier can be removed, and at the same time, the accumulation rate of particulate pollutants on the supporting rods in the carrier can be reduced, thereby increasing the service life of the carrier and reducing the frequency of preventive maintenance (PM) of the silicon wafer cleaning equipment.

The technical solution of the embodiment of the present invention is implemented as follows: In the first aspect, the embodiment of the present invention provides a carrier for cleaning silicon wafers, the carrier comprising a carrier frame for carrying silicon wafers composed of a plurality of supporting rods; each supporting rod comprises: a plurality of slots for inserting silicon wafers; a plurality of grooves evenly distributed along the circumferential direction on opposite sides of the slots, the grooves allowing the flow of cleaning liquid.

In a second aspect, an embodiment of the present invention provides an apparatus for cleaning silicon wafers, the apparatus comprising a carrier according to the first aspect.

In a third aspect, an embodiment of the present invention provides a silicon wafer, which is cleaned by the apparatus according to the second aspect.

The embodiment of the present invention provides a support device, equipment and silicon wafer for cleaning silicon wafers; the support device includes a support frame composed of multiple supporting rods for supporting silicon wafers; at the same time, for each supporting rod, multiple grooves evenly distributed along the circumferential direction of the support device are formed on the opposite sides of each slot, so that in the process of cleaning the silicon wafer, the fluidity of the cleaning liquid can be improved, the contaminants remaining on the surface of the supporting rod can be reduced, and the cleaning quality of the silicon wafer can be improved.

In order to help you understand the technical features, contents and advantages of the present invention and the effects it can achieve, the present invention is described in detail as follows with the accompanying drawings and appendices in the form of embodiments. The drawings used therein are only for illustration and auxiliary description, and may not be the true proportions and precise configurations after the implementation of the present invention. Therefore, the proportions and configurations of the attached drawings should not be interpreted to limit the scope of application of the present invention in actual implementation.

In the description of the embodiments of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

In the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be a connection between two components or an interaction relationship between two components. For those with ordinary knowledge in the field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to the specific circumstances.

At present, the related steps of silicon wafer cleaning in the conventional technical solution include a cleaning step and a rinsing step, wherein the cleaning step mainly adopts a cleaning liquid to wet-clean the silicon wafer. Specifically, as shown in FIG. 1 , a silicon wafer W is placed in a cleaning tank 1, and a standard cleaning liquid 1 (standard cleaning-1, SC-1) and a standard cleaning liquid 2 (standard cleaning-2, SC-2) are sequentially sprayed into the cleaning tank 1 to clean the silicon wafer W; wherein SC-1 is generally a mixed solution of ammonia water and hydrogen peroxide, and SC-2 is generally a mixed solution of hydrochloric acid and hydrogen peroxide. The rinsing step is a production step after the cleaning step. Specifically, as shown in FIG1 , the silicon wafer W with residual cleaning liquid on the surface is placed in a rinsing tank 2, and ultrapure water or ozone water is used to rinse the surface of the silicon wafer W. It should be noted that ultrasonic cleaning methods are used in both the cleaning step and the rinsing step to remove the residual particulate contaminants and metal ion impurities on the surface of the silicon wafer W to the greatest extent.

It should be noted that in the cleaning step and the rinsing step, the cleaning liquid or the rinsing liquid used a certain number of times will be discharged to the outside through the drain pipe (not shown in the figure) under the cleaning tank 1 or the rinsing tank 2 respectively. At the same time, the operator will fill the cleaning tank 1 and the rinsing tank 2 with new pollution-free cleaning liquid and new rinsing liquid again to clean the next batch of silicon wafers W.

However, referring to FIG. 2 and FIG. 3, which show schematic diagrams of a front view and a top view of the cleaning tank 1, as shown in FIG. 2 and FIG. 3, the cleaning tank 1 includes a tank body 21, in which a cleaning liquid is contained; on the other hand, a supporting device 22A is further provided on the tank body 21, wherein the supporting device 22A includes a supporting frame 31A composed of three supporting rods 311A, and the structure of each supporting rod 311A is specifically shown in FIG. 4 and FIG. 5. In combination with FIG. 4 and FIG. 5, it can be seen that each supporting rod 311A A plurality of slots 3111 are provided on the support rod 311A so that each silicon wafer W can be inserted into the support rod 311A through the slots 3111 to be fixed. For one support rod 311A, the distance between two adjacent slots 3111 is equal. Meanwhile, the slots 3111 on the three support rods 311A correspond to each other one by one. The bottoms of the three slots 3111 for inserting the same silicon wafer are on the same arc surface, and the radius of the arc surface is equal to the radius of the inserted silicon wafer W. However, it is understandable that in the conventional technical solution, when the cleaning liquid is discharged through the discharge pipe (not shown in the figure) at the bottom of the cleaning tank 1, the contaminants in the cleaning liquid will remain on the surface of the support rod 311A. This is mainly because during the cleaning liquid discharge process, the support rod 311A arranged in the tank body 21 slows down the flow of the cleaning liquid, causing the contaminants in the cleaning liquid to remain on the surface of the support rod 311A. It should be noted that even if the cleaning tank 1 is filled with new cleaning liquid, the above-mentioned contaminants will still remain in the new cleaning liquid to contaminate the silicon wafer W in the subsequent cleaning process. Secondly, when the silicon wafer W is inserted into the support rod 311A through the slot 3111, the impact of the cleaning liquid causes particles to be generated at the contact position between the silicon wafer W and the support rod 311A due to the influence of friction, as shown in Figures 6 and 7, which respectively show partial enlarged views of the contact positions. It can be understood that these contact positions are difficult to clean because the cleaning liquid cannot reach them, resulting in a large amount of particles accumulating at these contact positions. In the subsequent cleaning process of the silicon wafer W, these particles accumulated at the contact positions will affect the cleaning quality of the silicon wafer W, as well as the service life of the support rod 311A, and further affect the service life of the carrier 22A.

Based on the above description, the embodiment of the present invention hopes to improve the supporting device 22A so that the improved supporting device can speed up the flow of the cleaning liquid to reduce the contaminants remaining on the surface of the supporting rod, and at the same time can reduce the particle content and cumulative rate at the contact position between the silicon wafer W and the supporting rod. Specifically, as shown in FIG. 8 , a carrier 22 for cleaning a silicon wafer W provided by an embodiment of the present invention is shown. The carrier 22 includes a carrier frame 31 for supporting a silicon wafer W composed of a plurality of supporting rods 311; each supporting rod 311 includes: A plurality of slots 3111 for inserting and placing the silicon wafer W; A plurality of grooves 3112 uniformly distributed along the circumferential direction on opposite sides of the slots 3111, wherein the cleaning liquid is allowed to flow.

For the support device 22 shown in FIG8 , multiple grooves 3112 are evenly provided along the circumferential direction of the support device 22 on the opposite sides of the slot 3111, so as to improve the fluidity of the cleaning liquid and reduce the contaminants remaining on the surface of the support rod 311 during the cleaning of the silicon wafer W. Of course, it can also be understood that the multiple grooves 3112 provided in the support rod 311 can also speed up the flow of the cleaning liquid during the cleaning liquid discharge process to reduce the contaminants attached to the surface of the support rod 311.

For the supporting device 22 shown in Figure 8, in some possible embodiments, preferably, the width of the groove 3112 is not greater than the width of the slot 3111, and the depth of the groove 3112 is not greater than the depth of the slot 3111.

For the supporting device 22 shown in FIG. 8 , in some possible implementations, preferably, the groove 3112 is connected to the slot 3111 on the opposite side along the circumferential direction to communicate with the slot 3111 on the opposite side. As shown in FIG9 , in the embodiment of the present invention, in the specific implementation process, corresponding grooves 3112 can be opened on the opposite sides of each slot 3111. At the same time, in order to facilitate the processing of the grooves 3112, the slots 3111 and the grooves 3112 can be processed simultaneously along the circumferential direction of the support rod 311, so that the grooves 3112 are connected to the slots 3111 and are distributed in a ring shape. In this way, on the basis of ensuring the stability of the silicon wafer W, the fluidity of the cleaning liquid can be maximized, so that the cleaning liquid can flow at the maximum flow rate at the position of each silicon wafer W, thereby improving the cleaning quality of each silicon wafer W.

On the other hand, for the support device 22 shown in FIG8 , in some possible implementations, as shown in FIG10 , guide grooves 3113 are respectively provided along the radial direction at the contact position between the silicon wafer W and the support rod 311, and the cleaning liquid is allowed to flow in the guide grooves 3113. Specifically, as shown in FIG11 , guide grooves 3113 are respectively provided at the contact position between each silicon wafer W and each support rod 311, so as to maximize the fluidity of the cleaning liquid at the contact position between the silicon wafer W and the support rod 311, so as to be able to clean the contact position between the silicon wafer W and the support rod 311, thereby reducing the aggregation and accumulation rate of particles at the contact position between the silicon wafer W and the support rod 311.

Preferably, for the above possible implementation methods, in some examples, as shown in Figure 12, each of the guide grooves 3113 includes a direct flow groove 31131 and a plurality of branched flow grooves 31132, so that the cleaning liquid flows through the direct flow groove 31131 and then flows through each section of the multi-section branched flow grooves 31132. It can be understood that in order to improve the fluidity of the cleaning liquid, in the embodiment of the present invention, the number of the multi-section branched flow grooves 31132 is not specifically limited. The number of the multi-section branched flow grooves 31132 can be 3 as shown in Figure 12, or can be 5 as shown in Figure 13. The specific number is determined according to the specific size of the support rod 311.

Preferably, for the above possible implementation, in some examples, as shown in FIG. 14 , the guide groove 3113 includes a section of direct flow groove 31131, multiple sections of branched flow grooves 31132 and a section of branched flow groove 31133, so that the cleaning liquid reaches the branched flow groove 31133 after passing through the direct flow groove 31131 and flows through each section of the multiple sections of branched flow grooves 31132. It can be understood that in order to improve the cleaning fluidity at the contact position between the silicon wafer W and the support rod 311, it is also ensured that the silicon wafer W is cleaned. No shaking occurs during the process, so a diversion trough 31133 can be added after the direct current trough 31131 to ensure that the cleaning liquid flowing through the above-mentioned contact position has a stable flow rate; similarly, in the above-mentioned embodiment, there is no specific limitation on the number of multi-section branched flow troughs 31132, and the number of multi-section branched flow troughs 31132 can be 3 as shown in Figure 14, or can be 5 as shown in Figure 15, and the specific number is determined according to the specific size of the supporting device.

It should be noted that in the embodiment of the present invention, only the supporting device 22A in the cleaning tank 1 is improved, but the improved supporting device 22 is also applicable to the rinsing tank 2 to fix the silicon wafer W while improving the rinsing quality of the silicon wafer W.

Secondly, in the embodiment of the invention, a device for cleaning silicon wafers is also provided, which includes a supporting device according to the above-mentioned technical solution.

Finally, a silicon wafer is also provided in an embodiment of the invention, which is cleaned by the equipment described in the aforementioned technical solution.

It should be noted that the technical solutions described in the embodiments of the present invention can be combined arbitrarily without conflict.

It should be noted that the technical solutions described in the embodiments of the present invention can be combined arbitrarily without conflict. The above are only preferred embodiments of the present invention and are not intended to limit the scope of implementation of the present invention. If the present invention is modified or replaced by an equivalent method without departing from the spirit and scope of the present invention, it should be covered by the protection scope of the patent application of the present invention.

1: cleaning tank 2: rinsing tank 21: tank body 22: carrier 22A: carrier 31A: carrier frame 311: support rod 311A: support rod 3111: slot 3112: groove 3113: flow channel 31131: direct current channel 31132: branching flow channel W: silicon wafer

Figure 1 is a schematic diagram of a production process of cleaning silicon wafers provided in an embodiment of the present invention; Figure 2 is a schematic diagram of a top view of the structure of the cleaning tank in the conventional technical solution provided in an embodiment of the present invention; Figure 3 is a schematic diagram of a side view of the structure of the cleaning tank in the conventional technical solution provided in an embodiment of the present invention; Figure 4 is a schematic diagram of a front view of a support rod in the conventional technical solution provided in an embodiment of the present invention; Figure 5 is a schematic diagram of a top view of a support rod in the conventional technical solution provided in an embodiment of the present invention; Figure 6 is a schematic diagram of a side view of a partial enlarged view of the contact position between the silicon wafer and the support rod in the conventional technical solution provided in an embodiment of the present invention; Figure 7 is a schematic diagram of a top view of a partial enlarged view of the contact position between the silicon wafer and the support rod in the conventional technical solution provided in an embodiment of the present invention; FIG8 is a schematic diagram of a structure of a carrier device for cleaning a silicon wafer provided in an embodiment of the present invention; FIG9 is a schematic diagram of a structure of a groove provided on a support rod provided in an embodiment of the present invention; FIG10 is a schematic diagram of a structure of a guide groove provided in a support rod provided in an embodiment of the present invention; FIG11 is a schematic diagram of the positional relationship between a silicon wafer and a guide groove provided in an embodiment of the present invention; FIG12 is a schematic diagram of a structure of a guide groove provided in an embodiment of the present invention; FIG13 is a schematic diagram of another structure of a guide groove provided in an embodiment of the present invention; FIG14 is a schematic diagram of another structure of a guide groove provided in an embodiment of the present invention; FIG15 is a schematic diagram of another structure of a guide groove provided in an embodiment of the present invention.

1: Cleaning tank

2: Rinse tank

W: Silicon wafer

Claims (8)

A carrier device for cleaning silicon wafers, the carrier device comprises a carrier frame for carrying silicon wafers composed of a plurality of supporting rods; each supporting rod comprises: a plurality of slots for inserting silicon wafers; a plurality of grooves evenly distributed along the circumferential direction on the opposite sides of the slots, wherein a corresponding groove is opened on the opposite sides of each slot, and the slot and the groove are processed simultaneously along the circumferential direction of the supporting rod, so that the groove and the slot are connected and distributed in a ring shape, and the cleaning liquid is allowed to flow in the groove. A carrier device for cleaning silicon wafers as described in claim 1, wherein the width of the groove is not greater than the width of the slot, and the depth of the groove is not greater than the depth of the slot. A carrier device for cleaning silicon wafers as described in claim 1, wherein the groove extends into the slot on the opposite side along the circumferential direction to communicate with the slot on the opposite side. A carrier device for cleaning silicon wafers as described in claim 1, wherein a guide groove is provided along the radial direction at the contact position between each silicon wafer and the support rod, and the guide groove allows the cleaning liquid to flow. The carrier device for cleaning silicon wafers as described in claim 4, wherein each of the flow guide grooves includes a section of a direct flow groove and multiple sections of branched flow grooves, so that the cleaning liquid flows through the direct flow groove and then flows through each section of the branched flow groove. The carrier device for cleaning silicon wafers as described in claim 4, wherein the flow guide groove includes a section of direct flow groove, multiple sections of branched flow grooves and a section of branched flow groove, so that the cleaning liquid reaches the branched flow groove after passing through the direct flow groove and flows through each section of the branched flow groove. A device for cleaning silicon wafers, comprising a carrier for cleaning silicon wafers according to any one of claims 1 to 6. A silicon wafer, which is cleaned by the device for cleaning silicon wafers described in claim 7.

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