Developing device and substrate processing device

Abstract

The present application provides a developing device, which includes a housing, a wafer support located within the housing, the wafer support for supporting a wafer; a semi-permeable membrane disposed within the housing and dividing the housing into an upper housing and a lower housing, the upper housing defining an upper chamber, the lower housing defining a lower chamber, wherein the semi-permeable membrane is semi-permeable to vapor, allowing vapor to move from the lower chamber to the upper chamber, but inhibiting droplets of vapor from moving from the upper chamber to the lower chamber; and a nozzle assembly disposed above the wafer support and for spraying a developing solution at least toward the wafer support.

Description

Technical Field

[0001] This application generally relates to semiconductor manufacturing technology, and more specifically, to a developing apparatus for photolithography. Background Technology

[0002] The development process is a fundamental step in photolithography, which transfers the pattern in the photoresist to the wafer surface during substrate processing. Specifically, certain soluble areas of the photoresist can be dissolved by the developer, leaving islands or windows of photoresist on the wafer surface beneath the photoresist.

[0003] There are two common developing methods: continuous spray development and puddle development. Continuous spray development offers a faster development speed than puddle development because the fine mist of developer can be evenly deposited on the wafer as it rotates within the developing unit. However, continuous spray development can present a serious problem: the mist of developer or water ejected from the nozzles of the developing unit may immediately bounce off the wafer surface onto the housing of the developing unit, resulting in chemical droplets or water droplets potentially falling onto the wafer surface.

[0004] Therefore, an improved developing apparatus for photolithography is needed. Summary of the Invention

[0005] The purpose of this application is to provide a developing apparatus for photolithography that can prevent unwanted droplets from falling onto the wafer in the developing apparatus during the developing process.

[0006] According to one aspect of this application, a developing apparatus is provided, the developing apparatus including a housing; a wafer holder located within the housing for supporting a wafer; a semi-permeable diaphragm disposed within the housing and dividing the housing into an upper housing and a lower housing, the upper housing defining an upper chamber and the lower housing defining a lower chamber, wherein the semi-permeable diaphragm is semi-permeable to vapor, allowing vapor to move from the lower chamber to the upper chamber, but preventing vapor-formed droplets from moving from the upper chamber to the lower chamber; and a nozzle assembly positioned above the wafer holder and for spraying developing solution at least toward the wafer holder.

[0007] It should be understood that the foregoing general description and the following detailed description are exemplary and illustrative only, and not intended to limit the invention. Furthermore, the accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. Attached Figure Description

[0008] The accompanying drawings cited herein form part of the specification. The features shown in the drawings are only illustrations of some embodiments of this application, and not all embodiments of this application, unless otherwise expressly stated in the detailed description, and the reader of the specification should not draw the contrary inference.

[0009] Figure 1 A conventional developing apparatus is shown;

[0010] Figure 2 The image shows droplets on a wafer after development using a conventional developing apparatus.

[0011] Figure 3 A developing apparatus according to an embodiment of this application is shown;

[0012] Figure 4 It shows in Figure 3 The photograph shown is taken using a semi-permeable membrane in the developing apparatus.

[0013] Figure 5 It shows Figure 3 Another view of the developing apparatus shown;

[0014] The same reference numerals will be used to denote the same or similar parts in the accompanying drawings. Detailed Implementation

[0015] The following detailed description of exemplary embodiments of this application refers to the accompanying drawings, which form part of this specification. The accompanying drawings illustrate specific exemplary embodiments that may be implemented in this application. The detailed description, including the drawings, describes these embodiments in sufficient detail to enable those skilled in the art to implement this application. Those skilled in the art can further utilize other embodiments of this application and make logical, mechanical, and other changes without departing from the spirit or scope of this application. Therefore, the reader of the following detailed description should not interpret it in a limiting manner, and only the appended claims define the scope of the embodiments of this application.

[0016] In this application, unless otherwise expressly stated, the use of the singular includes the plural. In this application, unless otherwise stated, the use of “or” means “and / or”. Furthermore, the use of the term “comprising” and other forms such as “including” and “containing” is not restrictive. Furthermore, unless otherwise expressly stated, terms such as “element” or “part” cover elements and parts comprising one unit, as well as elements and parts comprising more than one subunit. Moreover, the section headings used herein are for organizational purposes only and should not be construed as limiting the subject matter described.

[0017] As used herein, spatially relative terms such as “below,” “under,” “above,” “over,” “upper,” “upper side,” “lower side,” “left side,” “right side,” “vertical,” “horizontal,” “side,” etc., may be used herein to describe the relationship between one element or feature and another element or feature as shown in the accompanying figures. In addition to the orientations depicted in the figures, spatially relative terms are intended to cover different orientations of the device in use or operation. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein may be interpreted accordingly. It should be understood that when an element is referred to as “connected to” or “coupled to” another element, it may be directly connected to or coupled to the other element, or there may be intermediate elements present.

[0018] Figure 1 A conventional developing apparatus 10 is shown, which can be used for photolithography to develop exposed photoresist.

[0019] like Figure 1 As shown, the developing apparatus 10 includes a housing 12, a wafer carrier 14, and a nozzle assembly 16. The housing 12 defines a chamber for housing the wafer carrier 14 and the nozzle assembly 16. When a wafer 20 is mounted on the wafer carrier 14 within the housing 12, a developer, such as a developing solution or other liquid (e.g., water), is sprayed from the nozzle assembly 16 onto the wafer 20, as shown in the first path 22. Although most of the kinetic energy of the sprayed liquid is absorbed by the photoresist coated on the wafer 20, a portion of the liquid can be bounced off the wafer 20 into the housing 12 in the form of small liquid particles or vapor, as shown in the second path 24. After moving along the second path 24, some of the bounced vapor can reach the inner surface of the housing 12 and accumulate there. After the spraying process, the small liquid particles and vapor accumulated on the inner surface of the housing 12 further condense and form droplets, which fall onto the wafer due to gravity, as shown in the third path 26. It is undesirable for droplets to fall onto wafer 20, as this could cause defects in the photoresist on wafer 20, which could subsequently lead to defects in the pattern on the wafer.

[0020] Figure 2 This is a photograph of a wafer after a developing process in which droplets form contaminants. This developing process is performed by... Figure 1 The process was performed using a conventional developing apparatus. It can be seen that there are water stains on the wafer surface. The semiconductor chip is covered by water stains (although...). Figure 2 If the wafer is not monolithically processed, it may become contaminated, which could reduce the yield of semiconductor chips from the wafer.

[0021] The inventors of this application have redesigned the structure of the developing apparatus, effectively solving the problem of dripping liquid from the developing apparatus. Figure 3A developing apparatus 300 according to an embodiment of this application is shown.

[0022] like Figure 3 As shown, the developing apparatus 300 includes a housing 302 defining a chamber. Various components can be arranged in the developing apparatus 300 to perform the developing process. Specifically, a wafer holder 304 is disposed within the housing 302, for example, at its bottom, to support a wafer 320 thereon. The wafer holder 304 may include a rotatable platform 310, a drive shaft 312, and a base 314. The rotatable platform 310 is located at the center of the wafer holder 304 and supports the wafer 320 with its top surface. The upper end of the drive shaft 312 is connected to the rotatable platform 310, and the lower end of the drive shaft 312 is connected to and supported by the base 314. When the drive shaft 312 rotates relative to a vertical axis, the rotatable platform 310 and the wafer 320 supported thereon can rotate accordingly. In some embodiments, the drive shaft 312 may be driven by a stepper motor, and in some other embodiments, the drive shaft 312 may be driven by some other actuation mechanism. The base 314 is located below the rotatable platform 310 and the drive shaft 312. In some embodiments, the base 314 is larger than the rotatable platform 310, such that the base 314 can collect liquids, such as developer and rinsing water, scattered from the wafer 320.

[0023] The developing apparatus 300 also includes a nozzle assembly 306 disposed above a wafer holder 304 within the housing 302. The nozzle assembly 306 is used to spray liquids usable during the developing process onto the wafer holder 304. For example, the nozzle assembly 306 may spray one or a combination of: rinsing water (e.g., deionized water), developer, or other desired solutions. To spray different types of liquids, the nozzle assembly 306 may include two or more nozzles, and each nozzle may be fluidly coupled to a liquid source outside the housing 302. In this embodiment, five nozzles may be arranged in a row, with three developer nozzles for spraying developer and two rinsing nozzles for spraying rinsing water. The positions and / or orientations of the nozzles may differ from each other to cover the entire top surface of the wafer 320. Because the rotatable platform 310 can rotate the wafer 320 relative to the nozzle assembly 306, the developer and rinsing water can be uniformly sprayed onto the wafer 320 to react with the photoresist coated on the wafer 320. In some embodiments, the developer may be an alkaline developing solution, such as a TMAH solution. Rinsing water can remove residual developer and photoresist debris from wafer 320. Figure 3In the illustrated embodiment, the nozzle assembly 306 can be suspended from the support arm 316 through an opening 318 at the top of the housing 302. In some embodiments, the distance between the nozzle assembly 306 and the wafer holder 304 can be adjusted by adjusting the height of the support arm 316. For example, the support arm 316 and the nozzle assembly 306 can be moved higher to cover a larger wafer, or they can be moved lower to cover a smaller wafer.

[0024] The developing apparatus 300 can perform the following developing processes: (a) the wafer can be placed on a rotatable platform 304 and then rotated by the rotatable platform 304; (b) the developer can be supplied from the developer nozzle to the wafer and diffused to the upper surface of the wafer due to the centrifugal force generated when the wafer is rotated, so that the photoresist coated on the wafer can be treated by the developer; (c) rinsing water can be supplied to the wafer from the rinsing nozzle to remove residual developer and photoresist debris on the wafer; and optionally (d) the wafer can be dried for subsequent processing, such as etching or selective deposition.

[0025] As previously mentioned, during the development process, vapor may bounce from the wafer 320 to the inner surface of the housing 302, particularly towards the upper part of the housing 302. To collect and capture these liquid particles or vapor, the developing apparatus 300 also includes a semi-permeable membrane 308 disposed within the housing 302. Figure 3 As shown, the semi-permeable membrane 308 divides the housing 302 into an upper housing that defines an upper chamber 303a and a lower housing that defines a lower chamber 303b. The nozzle assembly 306, the wafer 320, and the wafer support 304 are mainly located in the lower chamber 303b, so the lower chamber 303b occupies the main space inside the housing 302.

[0026] The semi-permeable membrane 308 is semi-permeable to vapor, allowing smaller liquid particles or vapor bouncing off the wafer 320 to move from the lower chamber 303b to the upper chamber 303a, but preventing larger droplets (which condense from vapor and drip due to gravity) from moving from the upper chamber 303a to the lower chamber 303b. In some embodiments, the semi-permeable membrane 308 comprises polypropylene, for example, made from a polypropylene film. Polypropylene is available from thermoplastic polymers that can be made from propylene monomers. A key advantage of polypropylene as a fabric is its vapor transfer capability; it does not absorb any vapor, but rather allows vapor to pass completely through the polypropylene fabric. This vapor transfer capability allows vapor to pass freely through the semi-permeable membrane 308, preventing droplets condensed from the vapor accumulating on the inner surface of the housing 302 from falling onto the wafer 320 in the lower chamber 303b. In some other embodiments, the semi-permeable membrane 308 may comprise polyethylene, polyurethane, polypropylene, or any combination thereof.

[0027] Specifically, developer or rinsing water can be sprayed from nozzle assembly 306 onto wafer 320, as shown in the first path 322. Then, vapor or small liquid particles can bounce off wafer 320 onto semi-permeable membrane 308, as shown in the second path 324. Semi-permeable membrane 308 allows vapor to move further to the inner surface of the upper housing. If a large amount of vapor accumulates on the inner surface of the upper housing, water droplets may condense from the vapor and fall onto semi-permeable membrane 308 via a third path 326, then flow over semi-permeable membrane 308 via a fourth path 328. In this way, droplets will not fall onto wafer 320 because wafer 320 is located directly below the central portion of semi-permeable membrane 308.

[0028] The semi-permeable membrane 308 can be formed into any other desired shape, depending on the shape of the upper housing 302. For example, the semi-permeable membrane 308 can be shaped as a dome or other suitable structure. A dome-shaped semi-permeable membrane 308 can prevent water droplets from accumulating in its central portion and facilitate the flow of water 328 towards the edges of the semi-permeable membrane 308. In some embodiments, guide channels or similar structures can be formed on the top surface of the semi-permeable membrane 308 to guide water towards the edges of the semi-permeable membrane 308. In some embodiments, the edges of the semi-permeable membrane 308 can be attached to the housing 302 and at least one outlet 330 can be located at the edge of the semi-permeable membrane 308, such that water can be discharged from the upper chamber 303a through the at least one outlet 330 and will not accumulate anywhere in the upper chamber 303a, as shown in the fifth path 331. In some embodiments, two outlets opposite to each other can be positioned at the edges of the semi-permeable membrane 308, or even more outlets can be provided at the edges. It is not desirable for the outlets 330 to be located directly above the wafer 320. In some embodiments, a guide channel or similar structure may be formed on the top surface of the semipermeable membrane 308 and fluidly coupled to an opening to guide water to the opening at the edge of the semipermeable membrane 308. Therefore, discharged droplets can fall outside the wafer 320 without forming contaminants on the wafer 320.

[0029] Figure 4 It shows in Figure 3 A photograph of the semi-permeable diaphragm used in the developing apparatus shown. (See image.) Figure 4 As shown, the semi-permeable diaphragm is shaped like a dome with a circular perimeter, which mates with the inner wall of the housing. Furthermore, an opening is formed in the central portion of the semi-permeable diaphragm, allowing the nozzle assembly to pass through it. Thus, a support arm for the nozzle assembly can pass through the opening from the housing to position a row of nozzles below the semi-permeable diaphragm.

[0030] In some embodiments, a hydrophilic coating (not shown) may be applied to the inner surface of the upper housing 302. The hydrophilic coating has an affinity for water and the contact angle of the water droplets is less than 30 degrees. Compared to a hydrophobic coating, water adhering to the hydrophilic coating does not immediately condense into droplets, but instead forms a water film on the inner surface of the hydrophilic coating. When the water film accumulates to a certain extent, the water can flow down along the inner surface of the hydrophilic coating along the sixth path 329 to the edge of the upper housing. In this way, the water can be guided to the outlet 330 at the edge of the semi-permeable membrane 308. In some embodiments, the hydrophilic coating may comprise nano-silica or any other similar material.

[0031] In some embodiments, an exhaust fan or other similar structure may be fluidly connected to the upper chamber 303a of the developing apparatus 300 to generate a pressure lower than that in the lower chamber 303b. In this way, the pressure difference can further facilitate the collection of vapor from the lower chamber 303b to the upper chamber 303a.

[0032] It is understood that the semi-permeable membrane described above can be similarly used in other substrate processing apparatuses. For example, the substrate processing apparatus may be a wafer or substrate cleaning apparatus that can spray liquids such as rinsing water, acidic solutions, and / or alkaline solutions onto substrates (e.g., wafers or printed circuit boards) mounted within the processing apparatus.

[0033] As previously described, the support arms can be used to support or suspend the nozzle assembly. In some embodiments, the developing apparatus 300 includes a plurality of support arms, each for mounting the nozzle of the nozzle assembly. Figure 5 It shows Figure 3 Another view of the developing apparatus 300 shown. (See diagram) Figure 5 As shown, five support arms are mounted on a bracket 340 outside the housing 302, and each support arm can be used to mount the nozzle of the nozzle assembly. The support arms can pass through the topmost opening of the housing 302 and the opening of the semi-permeable diaphragm.

[0034] The developing apparatus according to embodiments of this application has been tested compared to conventional developing apparatuses without a semi-permeable diaphragm. Specifically, 149 wafers were developed using a conventional developing apparatus, and water contaminants or stains were found on the surface of 20 of the 149 wafers. In contrast, 311 wafers were developed using the developing apparatus of this invention, and no contaminants or water stains were found on the surface of any of the 311 wafers. The test results demonstrate that the problem of water droplets on wafers can be effectively solved.

[0035] Various embodiments have been described herein with reference to the accompanying drawings. However, various modifications and alterations may be apparent therefrom, and other embodiments may be practiced, without departing from the broader scope of the invention as set forth in the appended claims. Furthermore, other embodiments will be apparent to those skilled in the art upon consideration of the implementation of one or more embodiments of the invention disclosed herein. Therefore, the embodiments in this application and herein are intended to be considered exemplary only, and the true scope and spirit of the invention are indicated by the appended exemplary claims.

Claims

1. A developing apparatus, the developing apparatus comprising: case; A wafer support, located within the housing, for supporting a wafer; A semi-permeable membrane is disposed within the housing and divides the housing into an upper housing and a lower housing, the upper housing defining an upper chamber and the lower housing defining a lower chamber, wherein the semi-permeable membrane is semi-permeable to vapor, allowing vapor to move from the lower chamber to the upper chamber, but preventing vapor droplets from moving from the upper chamber to the lower chamber; and A nozzle assembly positioned above the wafer scaffold and used to spray developer solution at least toward the wafer scaffold.

2. The developing apparatus according to claim 1, characterized in that, The developing apparatus further includes: A hydrophilic coating is disposed on the inner surface of the upper housing.

3. The developing apparatus according to claim 2, characterized in that, The upper housing includes an opening, and the semi-permeable diaphragm includes an opening corresponding to the opening of the upper housing, wherein the developing apparatus further includes: A support arm that passes through an opening in the upper housing and the semi-permeable diaphragm and is used to mount the nozzle assembly.

4. The developing apparatus according to claim 1, characterized in that, The semi-permeable membrane comprises polyethylene, polyurethane, or polypropylene, or any combination thereof.

5. The developing apparatus according to claim 1, characterized in that, The semi-permeable membrane is dome-shaped.

6. The developing apparatus according to claim 1, characterized in that, The semi-permeable membrane includes an edge along which it is attached to the housing, and at least one outlet is located at the edge, allowing water to drain from the upper chamber through the at least one outlet.

7. The developing apparatus according to claim 6, characterized in that, The at least one outlet is not above the wafer when the wafer holder supports the wafer.

8. A substrate processing apparatus, characterized in that, The substrate processing apparatus includes: case; A substrate support is located within the housing and is used to support the substrate. A semi-permeable membrane is disposed within the housing and divides the housing into an upper housing and a lower housing, the upper housing defining an upper chamber and the lower housing defining a lower chamber, wherein the semi-permeable membrane is semi-permeable to vapor, allowing vapor to move from the lower chamber to the upper chamber, but preventing vapor droplets from moving from the upper chamber to the lower chamber; and A nozzle assembly, which is positioned above the substrate support and sprays developing solution at least toward the substrate support.

9. The substrate processing apparatus according to claim 8, characterized in that, The substrate processing apparatus includes a hydrophilic coating, which is placed on the inner surface of the upper housing.

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