Method for retaining a processing solution on the surface of a semiconductor substrate

Abstract

Improved liquid reservoir formation steps and methods for retaining a processing liquid on the surface of a semiconductor substrate are provided herein. More specifically, improved methods for retaining a liquid reservoir within a central region of a semiconductor substrate while the substrate is stationary or rotating at a relatively low rotational speed are provided herein. In embodiments of the disclosure, the liquid reservoir is retained within the central region of the semiconductor substrate by a thin film, the thin film being deposited within the peripheral region of the substrate before the processing liquid is discharged into the central region of the substrate to form the liquid reservoir.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims the benefit of priority and the filing date of U.S. Patent Application No. 18 / 112,120, filed on February 21, 2023, the entire disclosure of which is incorporated herein by reference.

[0002] This disclosure relates to the processing of semiconductor substrates. In particular, this disclosure provides a novel method for holding a processing liquid on the surface of a semiconductor substrate.

Background Art

[0003] Semiconductor manufacturing processes can involve a variety of processing steps, including deposition steps, growth steps, patterning steps, etching steps, coating steps, development steps, and cleaning steps. Some of these processing steps can be spin - on processes that are performed on a semiconductor substrate while the semiconductor substrate is disposed within a processing chamber having a spin chuck and at least one liquid ejection nozzle.

[0004] FIG. 1A shows an example of a processing chamber 100 having a spin chuck 110 and at least one liquid ejection nozzle 120. In a conventional spin - on process, a semiconductor substrate (or wafer W) to be processed is positioned on the spin chuck 110 and held in place, for example, by a vacuum pressure or a mechanical pin holder. During various processing steps, the spin chuck 110 and the semiconductor substrate W mounted thereon can be rotated at a variable angular velocity by a drive mechanism 115, which can be, for example, a stepping motor. The drive mechanism 115 can rotate the spin chuck 110 at various rotational speeds while applying and flowing a liquid material onto the surface of the semiconductor substrate W.

[0005] At least one nozzle 120 may be provided in the processing chamber 100 to discharge one or more liquids onto the surface of the semiconductor substrate W. The nozzle 120 may be connected to a liquid supply unit (not shown) via a liquid supply line 125 to discharge various processing liquids (L) onto the surface of the semiconductor substrate W. The nozzle 120 may be configured to spray a desired amount of processing liquid in a mist onto the substrate surface or to drop a specific amount of processing liquid onto the substrate surface in a liquid puddle.

[0006] The processing solution supplied to the surface of the semiconductor substrate W depends on the processing steps being performed. For example, the nozzle 120 may discharge a processing solution onto the surface of the semiconductor substrate W to coat the substrate surface and form a layer of material (e.g., a metal layer, a dielectric layer, a photoresist, etc.) on the substrate surface. In some cases, a patterned layer is formed on the material layer, and then the material layer can be etched by discharging an etching solution from the nozzle 120 onto the patterned layer. In another example, the nozzle 120 may discharge a developer onto the surface of the semiconductor substrate W to develop a layer (e.g., a photoresist layer) that has been previously deposited on the substrate surface. In yet another example, the nozzle 120 may be used to clean and / or rinse the substrate surface by discharging a cleaning solution and / or rinsing solvent onto the surface of the semiconductor substrate W.

[0007] A cup 130 is provided within the processing chamber 100 to capture liquid released or dripping from the surface of the semiconductor substrate W. A spin chuck 110 and a drive mechanism 115 are positioned within the opening of the cup 130. The spin chuck 110 supports the semiconductor substrate W and rotates (i.e., spins) the semiconductor substrate W around its central normal axis relative to the stationary cup 130. As the spin chuck 110 rotates, the cup 130 captures and collects most of the processing liquid (L) released from the surface of the semiconductor substrate W by the centrifugal force generated during the rotation of the spin chuck 110. The liquid material released from the substrate W and collected by the cup 130 is drained through a drain line 135 and a drain unit (not shown). An exhaust line 137 and an exhaust unit (not shown), such as a vacuum pump or other negative pressure generating device, may be provided within the processing chamber 100 to remove gas species (including, but not limited to, vapors released from the substrate layer during processing) from the processing space inside the cup 130.

[0008] In some semiconductor manufacturing processes, the nozzle 120 may discharge a processing solution onto the surface of the semiconductor substrate W while the substrate is stationary or rotating at a relatively low rotational speed (e.g., 0-50 revolutions per minute (RPM)), thereby forming a liquid reservoir on the substrate surface. For example, a liquid reservoir may be formed on the substrate surface during processes such as developing, etching, and cleaning. The liquid reservoir may be used to reduce the amount of chemical solution required to carry out the process and to improve process performance.

[0009] In many cases, it is desirable to maintain complete chemical coating within the central region (or active region) of the semiconductor substrate W during the liquid reservoir formation process. However, due to the low surface tension of the liquid discharged onto the substrate and / or the inclined edges of the substrate, the liquid tends to drip from the edges of the substrate (even when the substrate is stationary), making it difficult to maintain complete chemical coating in conventional liquid reservoir formation processes.

[0010] Figure 1B shows a portion of the semiconductor substrate W shown in box 140 of Figure 1A. As shown in Figure 1B, the semiconductor substrate W includes a front surface 150, a back surface 160, a side edge surface 170, and a peripheral region 180 with a sloping edge. The sloping edge includes a front sloping edge 182 that slopes from the front surface 150 to the side edge surface 170, and a back sloping edge 184 that slopes from the back surface 160 to the side edge surface 170. When the processing liquid (L) is discharged onto the surface of the semiconductor substrate W (e.g., the front surface 150) while the substrate is stationary or rotating at a relatively low rotational speed, forming a liquid reservoir on the substrate surface, the relatively low surface tension of the processing liquid and / or the sloping edges 182 / 184 of the semiconductor substrate W may cause some of the processing liquid to fall off the edges of the substrate. This prevents the liquid reservoir formation process from maintaining a complete chemical coating within the central region of the semiconductor substrate W. [Overview of the project] [Problems that the invention aims to solve]

[0011] Therefore, an improved method for retaining the processing liquid on the surface of the semiconductor substrate during the liquid reservoir formation process is still needed. [Means for solving the problem]

[0012] This disclosure provides an improved liquid reservoir formation process and method for retaining a processing liquid on the surface of a semiconductor substrate. More specifically, this disclosure provides an improved method for retaining a liquid reservoir within a central region of a semiconductor substrate while the substrate is stationary or rotating at a relatively low rotational speed. In embodiments of the disclosure, the liquid reservoir is retained within a central region of the semiconductor substrate by a thin film, the thin film being deposited within a peripheral region of the substrate before the processing liquid is discharged into the central region of the substrate to form the liquid reservoir.

[0013] A thin film deposited only within the peripheral region of a semiconductor substrate and not within the central region is formed from a material having a surface energy lower than the surface energy of the substrate. The thin film formed within the peripheral region of the semiconductor substrate provides a low-energy surface that repels the processing liquid away from the peripheral region (as long as the substrate is stationary or rotating at a relatively low rotational speed), thereby retaining a liquid reservoir of the processing liquid within the central region of the semiconductor substrate. The thin film formed within the peripheral region of the semiconductor substrate improves upon conventional liquid reservoir formation processes by maintaining complete chemical coverage within the central region of the semiconductor substrate.

[0014] According to one embodiment, a method for holding a processing liquid on the surface of a semiconductor substrate is provided herein. In some embodiments, the method may begin by receiving a semiconductor substrate having a front surface, a back surface, a side edge surface, a peripheral region, and a central region. The peripheral region of the semiconductor substrate includes a side edge surface and annular portions of the front and back surfaces adjacent to the side edge surface. The central region of the semiconductor substrate extends from the center of the semiconductor substrate to the peripheral region.

[0015] Next, the method may include depositing a thin film on the surface of a semiconductor substrate and then discharging a processing solution onto the surface of the semiconductor substrate after the thin film has been deposited. The thin film is deposited only in the peripheral region of the semiconductor substrate and not in the central region. On the other hand, the processing solution is discharged into the central region of the semiconductor substrate, forming a reservoir of the processing solution within the central region. Since the thin film deposited in the peripheral region has a lower surface energy than the surface of the semiconductor substrate, the thin film provides a low-energy surface that repels the processing solution away from the peripheral region of the semiconductor substrate, thereby retaining the reservoir of the processing solution within the central region of the semiconductor substrate.

[0016] In some embodiments, the method may deposit a thin film by using a spin-on process to coat the entire peripheral region, including the side edge surface and the annular portions of the front and back surfaces of the semiconductor substrate, with a thin film.

[0017] In some embodiments, the method may deposit a thin film in the peripheral region of a semiconductor substrate while the semiconductor substrate is spinning at a first rotational speed, and the processing liquid may be discharged into the central region of the semiconductor substrate while the semiconductor substrate is stationary or spinning at a second rotational speed less than the first rotational speed, forming a reservoir of the processing liquid in the central region. In one embodiment, the first rotational speed may be selected from a first range of 200 to 3000 revolutions per minute (RPM), and the second rotational speed may be selected from a second range of 0 to 50 RPM.

[0018] In some embodiments, the method can deposit a thin film by depositing a material that is not etched or dissolved by a processing solution discharged into the central region of the semiconductor substrate within the peripheral region of the semiconductor substrate. For example, the thin film material deposited in the peripheral region may be a fluoropolymer material, a spin-on carbon (SOC) material, a spin-on silicon carbide (SiC) material, or a spin-on self-assembled monolayer (SAM). The processing solution discharged into the central region may include a cleaning solvent, a rinsing solvent, a drying solvent, a developing solvent, or an etching solution.

[0019] In some embodiments, the thin film may be deposited in a processing chamber including a front bevel nozzle. In such embodiments, the deposition of the thin film may involve using the front bevel nozzle to deposit material onto an annular portion of the front surface while spinning the semiconductor substrate at a certain rotational speed, thereby causing the deposited material to wrap around the side edge surface of the semiconductor substrate and cover the annular portion of the back surface.

[0020] In some embodiments, the thin film may be deposited in a processing chamber including a back-bevel nozzle. In such embodiments, the deposition of the thin film involves using the back-bevel nozzle to deposit material onto an annular portion of the back surface while spinning the semiconductor substrate at a certain rotational speed, thereby causing the deposited material to wrap around the side edge surface of the semiconductor substrate and cover the annular portion of the front surface.

[0021] In some embodiments, the thin film may be deposited in a processing chamber including a back nozzle. In such embodiments, the deposition of the thin film may involve using the back nozzle to deposit material on the back side of the semiconductor substrate near the center of the semiconductor substrate while spinning the semiconductor substrate at a certain rotational speed, thereby the deposited material covering the back surface and wrapping around the side edge surface of the semiconductor substrate to cover the annular portion of the front surface.

[0022] In some embodiments, the method may discharge a processing solution into a first processing chamber, and the method may further include transferring the semiconductor substrate from the first processing chamber to a second processing chamber after discharging the processing solution onto the surface of the semiconductor substrate. In such embodiments, a reservoir of the processing solution can be maintained within the central region of the semiconductor substrate during the transfer by depositing a thin film on the surface of the semiconductor substrate.

[0023] According to another embodiment, a method for cleaning the surface of a semiconductor substrate is provided herein. In some embodiments, the method may begin by receiving a semiconductor substrate having a front surface, a back surface, a side edge surface, a peripheral region, and a central region. The peripheral region of the semiconductor substrate includes a side edge surface and annular portions of the front and back surfaces adjacent to the side edge surface. The central region of the semiconductor substrate extends from the center of the semiconductor substrate to the peripheral region.

[0024] The method further includes depositing a thin film on the surface of a semiconductor substrate, wherein the thin film is deposited only in the peripheral region of the semiconductor substrate and not in the central region, and the thin film has a lower surface energy than the surface of the semiconductor substrate.

[0025] After depositing the thin film, the method may further include: (a) discharging a cleaning solvent onto the surface of the semiconductor substrate, the cleaning solvent being discharged into the central region of the semiconductor substrate over a first period while the semiconductor substrate is spinning; and (b) discharging the cleaning solvent into the central region of the semiconductor substrate over a second period while the semiconductor substrate is stationary to form a pool of the cleaning solvent in the central region. Since the thin film deposited in the peripheral region has a lower surface energy than the surface of the semiconductor substrate, the thin film provides a low-energy surface that repels the cleaning solvent away from the peripheral region of the semiconductor substrate and retains the pool of the cleaning solvent within the central region of the semiconductor substrate.

[0026] In some embodiments, the method may deposit the thin film by using a spin-on process to coat the entire peripheral region, including the side-edge surface of the semiconductor substrate and the annular portions of the front and back surfaces, with the thin film.

[0027] In some embodiments, the method may deposit the thin film by depositing a fluoropolymer material, a spin-on carbon (SOC) material, a spin-on silicon carbide (SiC) material, or a spin-on self-assembled monolayer (SAM) within the peripheral region of the semiconductor substrate.

[0028] In some embodiments, after discharging the cleaning solvent into the central region of the semiconductor substrate over the second period, additional steps may be performed. For example, the method may further include discharging the cleaning solvent into the central region of the semiconductor substrate over a third period while the semiconductor substrate is spinning, rinsing the surface of the semiconductor substrate with a rinse solvent to remove the cleaning solvent from the surface of the semiconductor substrate, and spinning the semiconductor substrate to dry the surface of the semiconductor substrate.

[0029] In yet another embodiment, a method for cleaning a semiconductor substrate is provided herein. In some embodiments, the method may begin by receiving a semiconductor substrate having a front surface, a back surface, a side edge surface, a peripheral region, and a central region. The peripheral region of the semiconductor substrate includes a side edge surface and annular portions of the front and back surfaces adjacent to the side edge surface. The central region of the semiconductor substrate extends from the center of the semiconductor substrate to the peripheral region.

[0030] The method further includes depositing a thin film on the surface of a semiconductor substrate, wherein the thin film is deposited only in the peripheral region of the semiconductor substrate and not in the central region, and the thin film has a lower surface energy than the surface of the semiconductor substrate.

[0031] After depositing a thin film, the method may further include (a) discharging a first solvent onto the surface of a semiconductor substrate after depositing the thin film, wherein the first solvent is discharged into the central region of the semiconductor substrate while the semiconductor substrate is spinning to clean the surface of the semiconductor substrate; (b) discharging a second solvent onto the surface of the semiconductor substrate after discharging the first solvent, wherein the second solvent is discharged into the central region of the semiconductor substrate while the semiconductor substrate is spinning to remove the first solvent from the surface of the semiconductor substrate; and (c) discharging a third solvent onto the surface of the semiconductor substrate after discharging the second solvent, wherein the third solvent is discharged into the central region of the semiconductor substrate while the semiconductor substrate is stationary to form a reservoir of the third solvent within the central region. Since the thin film deposited in the peripheral region has a lower surface energy than the surface of the semiconductor substrate, the thin film provides a low-energy surface that repels the third solvent away from the peripheral region of the semiconductor substrate and retains a reservoir of the third solvent within the central region of the semiconductor substrate.

[0032] In some embodiments, the method may deposit a thin film by using a spin-on process to coat the entire peripheral region, including the side edge surface and the annular portions of the front and back surfaces of the semiconductor substrate, with a thin film.

[0033] In some embodiments, the first solvent may be a cleaning solvent, the second solvent may be a rinsing solvent, and the third solvent may be a drying solvent.

[0034] In some embodiments, the method may discharge a first solvent, a second solvent, and a third solvent into a first processing chamber, and the method may further include discharging a third solvent onto the surface of a semiconductor substrate to form a reservoir of the third solvent in a central region, and then transferring the semiconductor substrate from the first processing chamber to a second processing chamber. In such embodiments, the reservoir of the third solvent in the central region of the semiconductor substrate can be maintained during the transfer by depositing a thin film on the surface of the semiconductor substrate.

[0035] In some embodiments, the first processing chamber may be a cleaning chamber, and the second processing chamber may be a supercritical processing chamber. In such embodiments, the method may further include treating the surface of a semiconductor substrate with supercritical carbon dioxide (CO2) and drying the surface of the semiconductor substrate. [Brief explanation of the drawing]

[0036] The present invention and its advantages can be better understood by referring to the following description, which is to be interpreted in conjunction with the accompanying drawings, in which similar reference numerals indicate similar features. However, it should be noted that the accompanying drawings only illustrate exemplary embodiments of the disclosed concept and should not be considered limiting in scope, as the disclosed concept may also encompass other equally valid embodiments.

[0037] [Figure 1A] (Prior Art) The interior of an exemplary processing chamber having a spin chuck for supporting and rotating a semiconductor substrate (W) and at least one nozzle for discharging a liquid onto the surface of the semiconductor substrate. [Figure 1B] (Prior Art) Figure 1A shows a portion of the semiconductor substrate (W) inside box 140. [Figure 2A]This is a top-down view of a semiconductor substrate having a front surface, a back surface (shown in Figure 2C), side edge surfaces, a peripheral region, and a central region. [Figure 2B] Figures 2A and 2C are side views of a semiconductor substrate, showing the side edge surface of the substrate. [Figure 2C] This is a view from below of a semiconductor substrate having a front surface (shown in Figure 2A), a back surface, side edge surfaces, peripheral regions, and a central region. [Figure 3] This flowchart shows one embodiment of a method for holding a processing solution on the surface of a semiconductor substrate using the technology described herein. [Figure 4A] This is a side cross-sectional view of a semiconductor substrate (W) showing a thin film deposited in the peripheral region of the substrate using a front-side bevel nozzle. [Figure 4B] This is a side cross-sectional view of a semiconductor substrate (W) showing a thin film deposited in the peripheral region of the substrate using a reverse bevel nozzle. [Figure 4C] This is a side cross-sectional view of a semiconductor substrate (W) showing a thin film deposited on the back surface of the substrate and within the peripheral region using a back nozzle. [Figure 5] As shown in Figures 4A to 4C, the interior of an exemplary processing chamber that can be used to deposit a thin film within the peripheral region of a semiconductor substrate (W) is shown. [Figure 6A] This is a side cross-sectional view of a semiconductor substrate (W) shown in Figure 4A or Figure 4B, showing the processing liquid discharged onto the front surface of the substrate and a liquid reservoir (P) of the processing liquid held in the central region of the substrate by a thin film formed in the peripheral region of the substrate. [Figure 6B] Figure 4C is a side cross-sectional view of a semiconductor substrate, showing the processing liquid discharged onto the front surface of the substrate and the liquid reservoir (P) of the processing liquid held within the central region of the substrate by a thin film formed within the peripheral region of the substrate. [Figure 6C] Figure 4A or Figure 4B shows a side cross-sectional view of a semiconductor substrate, illustrating the processing liquid discharged onto the front and back surfaces of the substrate, and the liquid reservoirs (P1 and P2) of the processing liquid held within the central region of the substrate by a thin film formed within the peripheral region of the substrate. [Figure 7]The interior of an exemplary processing chamber that can be used to discharge a processing solution onto at least one surface (e.g., the front surface and / or the back surface) of a semiconductor substrate (W) is shown. [Figure 8] This flowchart shows one embodiment of a method for cleaning the surface of a semiconductor substrate using the technology described herein. [Figure 9A] The following are exemplary process steps that may be performed to clean at least one surface of a semiconductor substrate, as illustrated in the method shown in Figure 8. [Figure 9B] The following are exemplary process steps that may be performed to clean at least one surface of a semiconductor substrate, as illustrated in the method shown in Figure 8. [Figure 9C] The following are exemplary process steps that may be performed to clean at least one surface of a semiconductor substrate, as illustrated in the method shown in Figure 8. [Figure 9D] The following are exemplary process steps that may be performed to clean at least one surface of a semiconductor substrate, as illustrated in the method shown in Figure 8. [Figure 9E] The following are exemplary process steps that may be performed to clean at least one surface of a semiconductor substrate, as illustrated in the method shown in Figure 8. [Figure 9F] The following are exemplary process steps that may be performed to clean at least one surface of a semiconductor substrate, as illustrated in the method shown in Figure 8. [Figure 10] This flowchart illustrates another embodiment of a method for cleaning the surface of a semiconductor substrate using the technique described herein. [Figure 11A] The following are exemplary process steps that can be performed to clean at least one surface of a semiconductor substrate, as illustrated in the method shown in Figure 10. [Figure 11B] The following are exemplary process steps that can be performed to clean at least one surface of a semiconductor substrate, as illustrated in the method shown in Figure 10. [Figure 11C] The following are exemplary process steps that can be performed to clean at least one surface of a semiconductor substrate, as illustrated in the method shown in Figure 10. [Figure 11D]The following are exemplary process steps that can be performed to clean at least one surface of a semiconductor substrate, as illustrated in the method shown in Figure 10. [Figure 11E] The following are exemplary process steps that can be performed to clean at least one surface of a semiconductor substrate, as illustrated in the method shown in Figure 10. [Figure 11F] The following are exemplary process steps that can be performed to clean at least one surface of a semiconductor substrate, as illustrated in the method shown in Figure 10. [Modes for carrying out the invention]

[0038] This disclosure provides an improved liquid reservoir formation process and method for retaining a processing liquid on the surface of a semiconductor substrate. More specifically, this disclosure provides an improved method for retaining a liquid reservoir within a central region of a semiconductor substrate while the substrate is stationary or rotating at a relatively low rotational speed. In embodiments of the disclosure, the liquid reservoir is retained within a central region of the semiconductor substrate by a thin film, the thin film being deposited within a peripheral region of the substrate before the processing liquid is discharged into the central region of the substrate to form the liquid reservoir.

[0039] A thin film deposited only within the peripheral region of a semiconductor substrate and not within the central region is formed from a material having a surface energy lower than the surface energy of the substrate. The thin film formed within the peripheral region of the semiconductor substrate provides a low-energy surface that repels the processing liquid away from the peripheral region (as long as the substrate is stationary or rotating at a relatively low rotational speed), thereby retaining a liquid reservoir of the processing liquid within the central region of the semiconductor substrate. The thin film formed within the peripheral region of the semiconductor substrate improves upon conventional liquid reservoir formation processes by maintaining complete chemical coverage within the central region of the semiconductor substrate.

[0040] Now, looking at the drawings, Figures 2A to 2C show a semiconductor substrate 200 (or wafer W). The semiconductor substrate 200 shown in Figures 2A to 2C can be any substrate on which the use of patterned features is desirable. In one embodiment, the semiconductor substrate 200 may be a semiconductor substrate on which one or more semiconductor processing layers are formed. For example, the semiconductor substrate 200 may be a substrate that has undergone multiple semiconductor processing steps resulting in a wide variety of structures and layers, all of which are known in substrate processing technology. In another embodiment, the semiconductor substrate 200 may be a conventional silicon substrate or other bulk substrate containing a layer of semiconducting material. The semiconductor substrate 200 shown in Figures 2A to 2C is disc-shaped and relatively thin. The diameter of the semiconductor substrate 200 may range from about 25 mm to 300 mm or even more.

[0041] As shown in Figures 2A to 2C, the semiconductor substrate 200 has a front surface 210, a back surface 220, a side edge surface 230, a peripheral region 240, and a central region 250. The peripheral region 240 of the semiconductor substrate 200 (shown by diagonal lines) includes the outer annular portion of the front surface 210, the side edge surface 230, and the outer annular portion of the back surface 220. The annular portions of the front surface 210 and the back surface 220 are located at the periphery of the semiconductor substrate 200 adjacent to the side edge surface 230. The width (w) of the annular portions of the front surface 210 and the back surface 220 is small compared to the diameter of the semiconductor substrate 200 (e.g., 300 mm). For example, the width (w) may be in the range of about 1 to 5 mm. In some embodiments, the annular portions of the front surface 210 and the back surface 220 may be inclined or include inclined edges, as shown in Figure 1B, for example.

[0042] As shown in Figures 2A and 2C, the central region 250 of the semiconductor substrate 200 extends from the center (C) of the semiconductor substrate 200 to the peripheral region 240. The central region 250 is the region of the semiconductor substrate 200 where semiconductor structures or active circuit components are formed. Unlike the central region 250, no semiconductor structures or active circuit components are formed in the peripheral region 240 (or bevel region) of the semiconductor substrate 200.

[0043] Figure 3 shows one embodiment of a method 300 for holding a processing solution on the surface of a semiconductor substrate, such as the semiconductor substrate 200 shown in Figures 2A to 2C, using the techniques described herein. The method shown in Figure 3 may be carried out in one or more semiconductor processing chambers. Examples of processing chambers that may be used to carry out the method steps shown in Figure 3 are shown in Figures 5 and 7 and described in more detail below. However, it should be recognized that the processing chambers shown and described herein are illustrative and that, as is known in the art, the method 300 may be carried out alternatively in other semiconductor processing chambers and systems.

[0044] In some embodiments, Method 300 may begin with receiving a semiconductor substrate (or wafer W) in step 310. The semiconductor substrate received in step 310 may generally include a front surface 210, a back surface 220, a side edge surface 230, a peripheral region 240, and a central region 250, as shown in Figures 2A-2C and described above. After receiving the semiconductor substrate in step 310, Method 300 deposits a thin film on the surface of the semiconductor substrate in step 320. In some embodiments, the thin film is deposited only in the peripheral region 240 of the semiconductor substrate in step 320, and not in the central region 250. In other embodiments, the thin film may be deposited in the peripheral region 240 along the back surface 220 of the semiconductor substrate, leaving the central region 250 of the front surface 210 free of thin film material.

[0045] In step 320, various thin-film materials can be deposited on the surface of the semiconductor substrate. Examples of thin-film materials that can be deposited on the substrate surface are discussed in more detail below. Regardless of the specific material used, the thin-film material deposited in step 320 preferably has a lower surface energy than the surface of the semiconductor substrate on which the thin film is deposited.

[0046] A wide variety of deposition processes can be used to deposit the thin film material onto the surface of the semiconductor substrate in step 320. Examples of deposition processes include, but are not limited to, chemical vapor deposition (CVD), plasma-enhanced CVD (PECVD), physical vapor deposition (PVD), atomic layer deposition (ALD), spin-on processes, and / or other deposition processes. In one embodiment, the thin film is preferably deposited by a spin-on deposition process in step 320. Unlike other spin-on processes used to deposit thin films, the spin-on deposition process described herein is preferably used to coat the entire peripheral region 240 with a thin film, including the side edge surfaces 230 and the outer annular portions of the front surface 210 and back surface 220 of the semiconductor substrate 200.

[0047] A spin-on deposition process can be used to eject a liquid onto the surface of a semiconductor substrate while the substrate is rotating or spinning at a specified rotational speed. In a spin-on deposition process, the liquid is ejected from one or more nozzles, which may be configured to atomize a desired amount of liquid onto the substrate surface or to drop a specific amount of liquid onto the substrate surface. The nozzles may be fixed or movable and may be positioned above and / or below the substrate surface depending on the surface to be coated with the liquid.

[0048] Figures 4A to 4C show various nozzles that may be used to deposit a thin film on the substrate surface in step 320 of Figure 3. For example, a front bevel nozzle 410 can be used to deposit a thin film 420 within the peripheral region 240 of the substrate 200, as shown in embodiment 400A. As shown in Figure 4A, the front bevel nozzle 410 is positioned above the bevel region on the front surface 210 of the semiconductor substrate 200. In some embodiments, the front bevel nozzle 410 may be used to deposit a thin film 420 within the peripheral region 240 of the substrate 200 by discharging a liquid material onto the outer annular portion of the front surface 210 while the semiconductor substrate 200 is spinning at a certain rotational speed (e.g., 200-3000 RPM). Depending on the rotational speed of the substrate 200, the liquid material discharged onto the outer annular portion of the front surface 210 wraps around the side edge surface 230 of the semiconductor substrate 200, at least partially covering the outer annular portion of the back surface 220 with the thin film 420. The degree of wrapping is determined by the viscosity of the liquid and the rotation speed of the substrate 200.

[0049] In other embodiments, the back bevel nozzle 412 may be used to deposit a thin film 422 within the peripheral region 240 of the substrate 200, as shown in embodiment 400B depicted in Figure 4B. The back bevel nozzle 412 is positioned below the bevel region on the back surface 220 of the semiconductor substrate 200. In some embodiments, the back bevel nozzle 412 may be used to deposit a thin film 422 within the peripheral region 240 of the substrate 200 by discharging a liquid material onto the outer annular portion of the back surface 220 while the semiconductor substrate 200 is spinning at a certain rotational speed (e.g., 200-3000 RPM). The rotational speed of the substrate 200 causes the liquid material discharged onto the outer annular portion of the back surface 220 to wrap around the side edge surface 230 of the semiconductor substrate 200, at least partially covering the outer annular portion of the front surface 210 with the thin film 422. Similar to the embodiments described above, the degree of wrapping is generally determined by the viscosity of the liquid and the rotational speed of the substrate 200.

[0050] In yet another embodiment, the back nozzle 414 may be used to deposit a thin film 424 within the peripheral region 240 of the substrate 200, as shown in embodiment 400C depicted in Figure 4C. The back nozzle 414 is positioned below the back surface 220 near the center of the semiconductor substrate 200. In some embodiments, the back nozzle 414 may be used to deposit a thin film 424 within the peripheral region 240 of the substrate 200 by discharging a liquid material onto the back surface 220 of the semiconductor substrate 200 near the center of the substrate 200 while the substrate 200 is spinning at a certain rotational speed (e.g., 200-3000 RPM). The rotational speed of the substrate 200 causes the liquid material discharged onto the back surface 220 to completely cover the back surface 220 and wrap around the side edge surface 230, at least partially covering the outer annular portion of the front surface 210 with the thin film 424. Here too, the degree of wrapping can be determined by the viscosity of the liquid and the rotation speed of the substrate 200.

[0051] Figure 5 shows an example of a processing chamber 500 that can be used to deposit thin films (e.g., thin films 420, 422, or 424) on the peripheral region 240 of a semiconductor substrate 200, as shown in Figures 4A to 4C and described above. In the processing chamber 500 shown in Figure 5, the semiconductor substrate (W) is mounted on a spin chuck 505 with its front side facing up and held in place, for example, by vacuum pressure. During various processing steps, the spin chuck 505 is rotated at a variable angular velocity by a drive mechanism (not shown), thereby causing the spin chuck 505 and the semiconductor substrate W mounted on it to spin at various rotational speeds.

[0052] In addition to the spin chuck 505, the processing chamber 500 includes various nozzles for dispensing liquid onto one or more surfaces of the semiconductor substrate W. The nozzles may be configured to dispense liquid onto the substrate surface while the semiconductor substrate W is stationary or spinning at various rotational speeds. In some embodiments, one or more nozzles may be used to dispense liquid material onto the surface of the semiconductor substrate W while the substrate is spinning at a specified rotational speed (e.g., 200-3000 RPM) to deposit a thin film on the peripheral region of the semiconductor substrate W.

[0053] In some embodiments, a back nozzle 510 located within the central region of the spin chuck 505 may be used to discharge a liquid material onto the back surface of the semiconductor substrate W while the substrate is spinning at a specified rotational speed, thereby forming a thin film 424 within the peripheral region 240 of the substrate 200. As shown in Figure 4C, the thin film 424 covers the entire back surface 220 and wraps around the side edge surface 230, at least partially covering or concealing the outer annular portion of the front surface 210 of the semiconductor substrate 200. This thin film configuration may be undesirable in some processes. For example, covering the entire back surface 220 of the semiconductor substrate 200 may be undesirable in some cleaning processes where cleaning solutions are supplied to the front and back surfaces 210 and 220 of the semiconductor substrate 200 to clean the substrate. In such processes, it may be preferable to form a thin film 420 or thin film 422 on the peripheral region 240 of the semiconductor substrate 200, as shown in Figures 4A and 4B.

[0054] As shown in Figure 5, the processing chamber 500 includes a top cover 515 positioned above a spin chuck 505 and a semiconductor substrate W mounted thereon. The top cover 515 includes an air inlet 520 for supplying clean, dry air to the semiconductor substrate W, and liquid supply lines 525 and a front bevel nozzle 530 for supplying various liquids to the substrate surface. As shown in Figures 4 and 5, the front bevel nozzle 410 / 530 is positioned above a bevel region on the front surface 210 of the semiconductor substrate 200. In some embodiments, as shown in Figure 4A, the front bevel nozzle 410 / 530 may be used to discharge a liquid material onto the outer annular portion of the front surface 210 of the semiconductor substrate 200 while the substrate is spinning at a specified rotational speed, thereby forming a thin film 420 within the peripheral region 240 of the substrate 200.

[0055] A drain cup 535 is provided in the processing chamber 500 to capture the liquid ejected from the surface of the semiconductor substrate W by the centrifugal force generated during the rotation of the spin chuck 505. The liquid ejected from the substrate surface is collected in a reservoir 540 provided in the drain cup 535 and drained through a drain line 545 and a drain unit (not shown). In some embodiments, an exhaust line and an exhaust unit (not shown) may be provided in the processing chamber 500 to remove gas species from the processing space inside the drain cup 535.

[0056] In some embodiments, a liquid supply line 550 and a back bevel nozzle 555 may be provided to supply various liquids to the substrate surface. As shown in Figures 4B and 5, the back bevel nozzles 412 / 555 are positioned below the bevel region on the back surface 220 of the semiconductor substrate 200. In some embodiments, as shown in Figure 4B, the back bevel nozzles 412 / 555 may be used to discharge a liquid material onto the outer annular portion of the back surface 220 of the semiconductor substrate 200 while the substrate is spinning at a specified rotational speed, thereby forming a thin film 422 within the peripheral region 240 of the substrate 200. The drain cup 535 may additionally include one or more gas nozzles 560 for supplying various gases (e.g., a purge gas such as nitrogen) to the back bevel region.

[0057] After depositing a thin film (e.g., thin films 420, 422, or 424) within the peripheral region 240 of the semiconductor substrate 200 in step 320, the method 300 shown in Figure 3 discharges a processing liquid onto the surface of the semiconductor substrate in step 330. The processing liquid may be discharged into the central region 250 of the semiconductor substrate 200 while the substrate is stationary or rotating at a relatively low rotational speed, forming a reservoir of processing liquid within the central region 250. A wide variety of processing liquids may be discharged onto the surface of the semiconductor substrate in step 330, depending on the process being performed. Examples of processing liquids are discussed in more detail below. Regardless of the specific liquid used, the processing liquid discharged in step 330 preferably has a relatively low surface tension, allowing the processing liquid to spread and uniformly cover (or wet) the central region 250 of the semiconductor substrate 200.

[0058] In method 300 shown in Figure 3, the thin film deposited in the peripheral region 240 of the semiconductor substrate in step 320 provides a lower energy surface (e.g., a non-wet surface) than the substrate surface. When the processing solution reaches the lower energy surface provided by the thin film, the molecular forces between the liquid molecules and the lower energy surface increase the local surface tension of the processing solution at the thin film boundary, resulting in a larger contact angle at the thin film boundary. The increased surface tension at the thin film boundary prevents the processing solution from spreading further over the thin film. By providing a lower energy surface than the substrate surface, the thin film deposited in step 320 effectively repels the processing solution discharged in step 330 away from the peripheral region 240 of the semiconductor substrate 200, retaining a reservoir of the processing solution within the central region 250 of the substrate. This enables method 300 shown in Figure 3 to achieve complete chemical coating of the processing solution within the central region 250 of the substrate, which represents a clear improvement over conventional reservoir formation processes. The reservoir retention techniques described herein are further illustrated in the embodiments shown in Figures 6A-6C.

[0059] Figures 6A to 6B show various embodiments (600A, 600B) in which a liquid reservoir (P) is formed within the central region 250 of the semiconductor substrate on the front surface 210 of the semiconductor substrate 200 and is held by thin films 420, 422, and 424 shown in Figures 4A to 4C. In the embodiments shown in Figures 6A to 6B, the liquid reservoir (P) is formed by discharging a processing liquid from a nozzle 610 positioned above the central region 250 of the front surface 210 of the semiconductor substrate while the semiconductor substrate 200 is stationary or spinning at a relatively low rotational speed (e.g., 0 to 50 RPM).

[0060] Figure 6C shows an embodiment (600C) in which liquid reservoirs (P1 and P2) are formed within the central region 250 of the semiconductor substrate 200 on the front surface 210 and the back surface 220 of the substrate. The liquid reservoirs (P1 and P2) shown in Figure 6C may be held by the thin film 420 shown in Figure 4A or the thin film 422 shown in Figure 4B. In the embodiment shown in Figure 6C, liquid reservoir (P1) is formed by discharging a processing liquid from a nozzle 610 positioned above the central region 250 of the front surface 210 of the semiconductor substrate 200 while the substrate is stationary or spinning at a relatively low rotational speed (e.g., 0 to 50 RPM), and liquid reservoir (P2) is formed by discharging a processing liquid from a nozzle 620 positioned below the central region 250 of the back surface 220 of the semiconductor substrate 200 while the substrate is stationary or spinning at a relatively low rotational speed (e.g., 0 to 50 RPM).

[0061] As described above, the processing liquid discharged from the nozzles 610 / 620 may have a relatively low surface tension, allowing the processing liquid to spread and uniformly cover (or wet) the central region 250 of the semiconductor substrate 200. When the processing liquid discharged into the central region 250 comes into contact with the low-energy surface of the thin films 420, 422, or 424 deposited in the peripheral region 240, the increased surface tension at the thin film boundary effectively pushes the processing liquid away from the peripheral region 240 of the semiconductor substrate 200, as shown in Figures 6A to 6C, and the liquid reservoir of the processing liquid is retained within the central region 250 of the substrate.

[0062] Figure 7 shows an exemplary processing chamber 700 that can be used to discharge a processing liquid onto at least one surface of a semiconductor substrate 200 (e.g., the front surface and / or the back surface). The processing chamber 700 shown in Figure 7 may generally include a spin chuck 705 (e.g., a mechanical or vacuum chuck) for holding a semiconductor substrate (W) on the spin chuck 705, a drive mechanism 715 for rotating the spin chuck 705 at various rotational speeds, a pair of nozzles 710 and 720 for discharging a liquid (L) onto one or more surfaces of the substrate W, and a cup 730 for capturing the liquid discharged from the surface of the substrate W by the centrifugal force generated during the rotation of the spin chuck 705. As shown in Figure 7, the cup 730 may include a drain line 735 and a drain unit (not shown) for draining the liquid discharged from the substrate surface, and an exhaust line 737 and an exhaust unit (not shown) for removing gas species from the processing space inside the cup 730.

[0063] In the embodiment shown in Figure 7, the processing chamber 700 includes a front nozzle 710 and a back nozzle 720. The front nozzle 710 is positioned above the semiconductor substrate W to discharge the processing liquid onto the front surface of the semiconductor substrate W (e.g., the front surface 210). The back nozzle 720 is located within the central region of the spin chuck 705 to discharge the processing liquid onto the back surface of the semiconductor substrate W (e.g., the back surface 220). The nozzles 710 and 720 can discharge the processing liquid onto one or more surfaces of the semiconductor substrate W while the semiconductor substrate W is stationary or spinning at a specified rotational speed.

[0064] Nozzles 710 and 720 can be used to discharge a wide variety of processing solutions onto the surface of the semiconductor substrate W, depending on the processing performed in the processing chamber 700. In one example, when a cleaning process is performed in the processing chamber 700, nozzles 710 and 720 can be used to discharge a cleaning solvent, a rinsing solvent, and / or a drying solvent onto one or more surfaces of the substrate W. In another example, when a photoresist patterning process is performed, nozzles 710 and 720 can be used to discharge a coating material (e.g., photoresist) and a developing solvent onto one or more surfaces of the substrate W. In yet another example, when an etching process is performed, nozzles 710 and 720 can be used to discharge an etching solution onto one or more surfaces of the substrate W. Other processing solutions can also be discharged onto the surface of the substrate W when other processing is performed in the processing chamber 700, as is known in the art.

[0065] In some embodiments, nozzles 710 and 720 may be used to discharge a processing solution onto the surface of the semiconductor substrate W while the substrate W is spinning at a first rotational speed, in order to uniformly apply a coating layer onto the surface of the substrate W, or to clean or rinse the surface of the substrate W. In other embodiments, as shown in Figures 6A to 6C and described above, nozzles 710 and 720 may be used to discharge a processing solution onto the surface of the semiconductor substrate W while the substrate W is stationary or spinning at a second rotational speed less than the first rotational speed, in order to form a liquid reservoir (P) within the central region 250 of the substrate. In some embodiments, the first rotational speed may be in the range of 100 to 2000 RPM, and the second rotational speed may be in the range of 0 to 50 RPM.

[0066] As described above, in step 320 of method 300 shown in Figure 3, a wide variety of thin film materials can be deposited on the surface of the semiconductor substrate. In addition to having a surface energy lower than the surface energy of the semiconductor substrate, the thin film material deposited in the peripheral region 240 of the substrate 200 is preferably a material that is not etched or dissolved by the processing solution discharged in step 330 of method 300 shown in Figure 3. In other words, the thin film material deposited in the peripheral region 240 is a material that is compatible with the processing solution discharged into the central region 250 of the substrate 200.

[0067] Examples of thin-film materials that can be deposited in the peripheral region 240 of the semiconductor substrate 200 include, but are not limited to, fluoropolymer materials, spin-on carbon (SOC) materials, spin-on silicon carbide (SiC) materials, and spin-on self-assembled monolayers (SAMs). Examples of fluoropolymer films include polytetrafluoroethylene (PTFE) and perfluoroalkoxy (PFA). When these thin-film materials are applied to the peripheral region 240 of the semiconductor substrate 200, they provide a low-energy surface (e.g., a non-wetting surface) that repels or otherwise prevents the adhesion of processing liquids subsequently discharged onto the substrate surface. When the processing liquid comes into contact with the low-energy surface of the thin-film material, the local surface tension increases, resulting in a larger contact angle between the processing liquid and the low-energy surface. This prevents the processing liquid from adhering to the thin-film material and spreading over it. In some cases, the low-energy surface may be a hydrophobic surface that repels or otherwise prevents water from adhering to the thin-film material.

[0068] The thin-film materials and liquid reservoir retention techniques described herein can be used to retain liquid reservoirs on the surface of semiconductor substrates during a wide variety of processes. Figures 8 to 11 provide various examples of cleaning processes that can be improved by utilizing the liquid reservoir retention techniques described herein. However, it is recognized that other processes can be similarly improved by utilizing the techniques described herein. For example, the techniques disclosed may also be used to retain liquid reservoirs on the surface of semiconductor substrates during developing processes, etching processes, and so on.

[0069] Figures 8 and 9A-9F illustrate one embodiment of an improved method 800 for cleaning the surface of a semiconductor substrate. As shown in Figure 8, the method 800 may begin by receiving the semiconductor substrate in step 810. The semiconductor substrate received in step 810 may generally include a front surface 210, a back surface 220, a side edge surface 230, a peripheral region 240, and a central region 250, as shown in Figures 2A-2C and described above.

[0070] After receiving the semiconductor substrate in step 810, method 800 deposits a thin film on the surface of the semiconductor substrate in step 820. In method 800, the thin film is deposited only within the peripheral region 240 of the semiconductor substrate in step 820, and not within the central region 250. In other words, the thin film can only be formed within the bevel region of the substrate. In some embodiments, a spin-on deposition process may be used in step 820 to coat the entire peripheral region 240 with a thin film, including the side edge surface 230 of the semiconductor substrate 200 and the annular portions of the front surface 210 and back surface 220.

[0071] In some embodiments, the deposition chamber shown in Figure 5 may be used to carry out a spin-on deposition process used to deposit a thin film in step 820. The processing chamber 500 may be used to deposit a thin film (e.g., thin films 420, 422, or 424), for example, as shown in Figures 4A, 4B, or 4C. If it is desirable to clean the front surface 210 and back surface 220 of the semiconductor substrate 200, a thin film 420 or 422, as shown in Figure 4A or 4B, may be formed in the peripheral region 240 of the substrate 200. In some embodiments, the semiconductor substrate may be transferred from the deposition chamber to the cleaning chamber after the thin film has been deposited in step 820. In some embodiments, a bake process may be carried out after the thin film has been deposited in step 820 and before the semiconductor substrate is transferred to the cleaning chamber (to evaporate the solvent in the thin film material). Figure 9A shows an embodiment (900) in which the semiconductor substrate 200, with a thin film deposited in the peripheral region 240 (or bevel region) of the substrate 200, is received into the cleaning chamber.

[0072] Various thin-film materials can be deposited on the surface of the semiconductor substrate (in step 820) to form a thin film within the peripheral region 240 of the substrate 200. Examples of thin-film materials that can be deposited on the substrate surface are discussed in more detail above. For example, the thin-film material deposited in step 820 may be a fluoropolymer material (e.g., PTFE or PFA), a spin-on carbon (SOC) material, a spin-on silicon carbide (SiC) material, or a spin-on self-assembled monolayer (SAM). Regardless of the specific material used, the thin-film material deposited in step 820 preferably has a surface energy lower than the surface energy of the semiconductor substrate on which the thin film is deposited. This low-energy surface allows the processing solution (such as a cleaning solvent, rinsing solvent, and / or drying solvent) to move away from the peripheral region 240 in the direction that the thin film deposited in step 820 is away from. In addition, the thin-film material deposited in step 820 may be compatible with the processing solution, and as a result, the thin-film material is not etched or dissolved by the processing solution.

[0073] After depositing a thin film (e.g., thin films 420, 422, or 424) in the peripheral region 240 of the semiconductor substrate 200 in step 820, Method 800, as shown in Figure 8, discharges a cleaning solvent onto the surface of the semiconductor substrate in step 830. In Method 800, the cleaning solvent is discharged into the central region 250 of the semiconductor substrate 200 over a first period while the semiconductor substrate is spinning, for example at a first rotation speed (e.g., 100 and 2000 RPM). In some embodiments, the cleaning solvent may be discharged to only one surface of the semiconductor substrate (e.g., the front surface 210) in step 830. In other embodiments, the cleaning solvent may be discharged to both the front surface 210 and the back surface 220 of the semiconductor substrate 200 in step 830, as shown in Embodiment 910 of Figure 9B.

[0074] In step 830, a wide variety of cleaning solvents can be discharged. For example, various standard cleaning solvents 1 (SC1) and 2 (SC2), including ammonia / hydrogen peroxide mixture (APM), hydrochloric acid / hydrogen peroxide mixture (HPM), and / or sulfuric acid / hydrogen peroxide mixture (SPM), can be used in step 830. Other cleaning solvents can also be used in step 830, as are known in the art. As the semiconductor substrate spins, the cleaning solvent discharged onto the surface of the semiconductor substrate is released from the surface, captured by the cup, and discharged through the drain line.

[0075] After the cleaning solvent is discharged in step 830, a cleaning liquid reservoir formation step may be performed to improve cleaning performance and reduce the amount of cleaning solvent used. For example, in step 840, the cleaning solvent may be discharged into the central region 250 of the semiconductor substrate 200 over a second period while the semiconductor substrate is stationary, thereby forming a reservoir (P) of the cleaning solvent within the central region 250. In some embodiments, the cleaning solvent may be discharged in step 840 onto the front surface 210 and the back surface 220 of the semiconductor substrate 200, as shown in embodiment 920 of Figure 9C, thereby forming a reservoir (P1) on the front surface 210 and a reservoir (P2) on the back surface 220. As described above and as shown in Figure 9C, the thin film deposited on the surface of the semiconductor substrate in step 820 provides a low-energy surface that repels the cleaning solvent away from the peripheral region 240 of the semiconductor substrate 200 in step 840, thereby retaining the reservoir (P) of the cleaning solvent within the central region 250 of the substrate.

[0076] After performing the cleaning solution reservoir formation step as described in step 840 and shown in Figure 9C, the method 800 shown in Figure 8 may perform a second cleaning step (in step 850) by discharging the cleaning solution into the central region 250 of the semiconductor substrate over a third period while the semiconductor substrate is spinning, as shown in embodiment 930 in Figure 9D, before rinsing the surface of the semiconductor substrate 200 with a rinsing solvent (in step 860) to remove the cleaning solvent from the surface of the semiconductor substrate, as shown in embodiment 940 in Figure 9E. Various rinsing solvents may be used to rinse the surface of the semiconductor structure in step 860. In some embodiments, deionized water may be used as the rinsing solvent. As the semiconductor substrate spins, the cleaning solvent and rinsing solvent discharged onto the surface of the semiconductor substrate are released from the surface, captured by the cup, and discharged through the drain line. After the surface of the semiconductor substrate is rinsed in step 860, method 800 may continue to spin the semiconductor substrate (in step 870) to dry the surface of the semiconductor substrate in a spin-drying step, as shown in embodiment 950 of Figure 9F.

[0077] Figures 10 and 11A–11F show another embodiment of the improved method 1000 for cleaning the surface of a semiconductor substrate. Similar to method 800 shown in Figure 8, method 1000 shown in Figure 10 may generally begin with receiving a semiconductor substrate in step 1010 and depositing a thin film on the surface of the semiconductor substrate in step 1020. The semiconductor substrate and the thin film may generally be configured as described above with reference to steps 810 and 820.

[0078] In some embodiments, a spin-on deposition process may be used in step 1020 to coat the entire peripheral region 240 of the semiconductor substrate 200 with a thin film, including the side edge surface 230 and the annular portions of the front surface 210 and back surface 220. In some embodiments, a deposition chamber may be used in step 1020 to perform the spin-on deposition process and deposit the thin film before the semiconductor substrate is transferred to a cleaning chamber. In some embodiments, a bake process may be performed after the thin film has been deposited and before the semiconductor substrate is transferred to a cleaning chamber (to evaporate the solvent in the thin film material). Figure 11A shows an embodiment (1100) in which a semiconductor substrate 200 with a thin film deposited in the peripheral region 240 (or bevel region) of the substrate 200 is received into a cleaning chamber.

[0079] In step 1030, method 1000 discharges a first solvent onto the surface of the semiconductor substrate after the thin film has been deposited in step 1020. In method 1000, the first solvent is discharged into the central region 250 of the semiconductor substrate while the semiconductor substrate is spinning in order to clean the surface of the semiconductor substrate. The first solvent may be a cleaning solvent, as described above. In some embodiments, the first solvent may be discharged in step 1030 only onto one surface of the semiconductor substrate (e.g., the front surface 210). In other embodiments, the first solvent may be discharged in step 1030 onto both the front surface 210 and the back surface 220 of the semiconductor substrate 200, as shown in embodiment 1110 of Figure 11B.

[0080] In step 1040, method 1000 discharges a second solvent onto the surface of the semiconductor substrate after discharging the first solvent in step 1030. In method 1000, the second solvent is discharged into the central region 250 of the semiconductor substrate 200 while the semiconductor substrate is spinning, removing the first solvent from the surface of the semiconductor substrate. The second solvent may be a rinse solvent, as described above. In some embodiments, the second solvent may be discharged in step 1040 onto only one surface of the semiconductor substrate (e.g., the front surface 210). In other embodiments, the second solvent may be discharged in step 1040 onto both the front surface 210 and the back surface 220 of the semiconductor substrate 200, as shown in step 1120 of Figure 11C.

[0081] In step 1050, method 1000 discharges a third solvent onto the surface of the semiconductor substrate after discharging the second solvent in step 1040. In method 1000, the third solvent is discharged into the central region 250 of the semiconductor substrate while the semiconductor substrate is stationary, forming a reservoir (P) of the third solvent within the central region 250. The third solvent may be a drying solvent such as isopropyl alcohol (IPA). In some embodiments, the third solvent may be discharged onto the front surface 210 of the semiconductor substrate 200 in step 1050, as shown in step 1130 of Figure 11D, forming a reservoir (P) on the front surface 210.

[0082] In some embodiments, method steps 1030, 1040, and 1050 may be carried out in a cleaning chamber, for example, as shown in Figure 7. In some embodiments, method 1000 may transfer the semiconductor substrate from the cleaning chamber to another processing chamber in step 1060, after in step 1050 a third solvent is discharged onto the surface of the semiconductor substrate 200 to form a reservoir (P) of the third solvent within the central region 250 of the substrate. In some embodiments, the semiconductor substrate with the reservoir (P) formed on it may be transferred to a supercritical processing chamber, for example, as shown in embodiments 1140 and 1150 depicted in Figures 11E and 11F. Once transferred to the supercritical processing chamber, method 1000 may treat the surface of the semiconductor substrate with supercritical carbon dioxide (CO2) before drying the surface of the semiconductor substrate.

[0083] In method 1000 shown in Figure 10, the thin film deposited on the surface of the semiconductor substrate in step 1120 provides a low-energy surface that retains a reservoir (P) of the third solvent within the central region 250 of the semiconductor substrate 200, by moving the third solvent away from the peripheral region 240 of the semiconductor substrate 200. The reservoir (P) is retained not only during the reservoir formation process shown in Figure 11D, but also during the wafer transfer process shown in Figure 11E. This enhances the performance of the reservoir cleaning process and the supercritical CO2 drying process, representing a clear advantage over conventional cleaning processes.

[0084] Systems and methods for processing substrates are described in various embodiments. A substrate may include any material portion or structure of a device, particularly a semiconductor or other electronic device, and may be a base substrate structure such as a semiconductor substrate, or a layer on a base substrate structure or a layer superimposed on a base substrate structure. Accordingly, the term “substrate” is not intended to be limited to any particular base structure, underlay or toplay, patterned or unpatterned layer, but rather is intended to include any such layer or base structure, and any combination of layers and / or base structures.

[0085] As used herein, the term “substrate” means and includes a base material or structure on which a material is formed. It will be understood that a substrate may include a single material, multiple layers of different materials, regions of different materials or different structures, etc. These materials may include semiconductors, insulators, conductors, or combinations thereof. For example, a substrate may be a semiconductor substrate, a base semiconductor layer on a support structure, a metal electrode, or a semiconductor substrate on which one or more layers, structures, or regions are formed. A substrate may be a conventional silicon substrate or another bulk substrate including a layer of semiconducting material. As used herein, the term “bulk substrate” means and includes not only silicon wafers but also silicon-on-sapphire ("SOS") substrates and silicon-on-glass ("SOG") substrates such as silicon-on-insulator ("SOI") substrates, an epitaxial layer of silicon on a base semiconductor substrate, and other semiconductor or optoelectronic materials such as silicon germanium, germanium, gallium arsenide, gallium nitride, and indium phosphide. The circuit board may be doped or undoped.

[0086] Throughout this specification, any reference to “one embodiment” or “an embodiment” means that certain features, structures, materials, or properties described in relation to that embodiment are included in at least one embodiment of the present invention, but not that they are present in all embodiments. Therefore, the appearance of the phrase “in one embodiment” or “in an embodiment” in various places throughout this specification does not necessarily refer to the same embodiment of the present invention. Furthermore, certain features, structures, materials, or properties may be combined in any suitable manner in one or more embodiments. Various additional layers and / or structures may be included, and / or described features may be omitted.

[0087] Those skilled in the art will recognize that various embodiments can be carried out without one or more specific details, or using other alternative and / or additional methods, materials, or components. In other examples, well-known structures, materials, or operations are not illustrated or described in detail so as not to obscure the aspects of the various embodiments of the present invention. Similarly, a specific number, materials, and configurations are described for illustrative purposes in order to provide a full understanding of the present invention. Nevertheless, the present invention can be carried out without specific details. Furthermore, it should be understood that the various embodiments shown in the figures are illustrative representations and are not necessarily drawn to scale.

[0088] A review of this specification will reveal to those skilled in the art further modifications and alternative embodiments of the systems and methods described herein. Therefore, it will be recognized that the systems and methods described are not limited by these exemplary configurations. It should be understood that the forms of systems and methods illustrated and described herein should be interpreted as exemplary embodiments. Various modifications may be made to the embodiments. Therefore, although the invention is described herein with reference to specific embodiments, various modifications and changes can be made without departing from the scope of the invention. Thus, this specification and the drawings should be considered exemplary rather than restrictive, and such modifications are intended to be included within the scope of this disclosure. Furthermore, no benefit, advantage, or solution to a problem described herein with respect to a specific embodiment is intended to be interpreted as any or all important, necessary, or essential feature or element of the claims.

Claims

1. A method for holding a processing liquid on the surface of a semiconductor substrate, wherein the method is The act of receiving the semiconductor substrate, wherein the semiconductor substrate has a front surface, a back surface, a side edge surface, a peripheral region, and a central region, the peripheral region includes the side edge surface and the annular portions of the front surface and the back surface adjacent to the side edge surface, and the central region extends from the center of the semiconductor substrate to the peripheral region, the act of receiving, The method of depositing a thin film on the surface of the semiconductor substrate, wherein the thin film is deposited only within the peripheral region of the semiconductor substrate and not within the central region, and the thin film has a lower surface energy than the surface of the semiconductor substrate. The process involves discharging the processing liquid onto the surface of the semiconductor substrate after depositing the thin film, wherein the processing liquid is discharged into the central region of the semiconductor substrate, forming a reservoir of the processing liquid within the central region. Includes, A method for providing a low-energy surface in which the processing liquid is moved away from the peripheral region of the semiconductor substrate by depositing the thin film on the surface of the semiconductor substrate, thereby maintaining the liquid reservoir of the processing liquid within the central region of the semiconductor substrate.

2. The method according to claim 1, wherein the deposition of the thin film includes, using a spin-on process, covering the entire peripheral region with the thin film, including the side edge surface of the semiconductor substrate and the annular portions of the front surface and the back surface.

3. The method according to claim 1, wherein depositing the thin film includes depositing the thin film in the peripheral region of the semiconductor substrate while the semiconductor substrate is spinning at a first rotational speed, and discharging the processing liquid includes discharging the processing liquid into the central region of the semiconductor substrate while the semiconductor substrate is stationary or spinning at a second rotational speed less than the first rotational speed, thereby forming a reservoir of the processing liquid in the central region.

4. The method according to claim 3, wherein the first rotational speed is selected from a first range consisting of 200 to 3000 revolutions per minute (RPM), and the second rotational speed is selected from a second range consisting of 0 to 50 RPM.

5. The method according to claim 1, wherein the deposition of the thin film includes depositing a material that is not etched or dissolved by the processing solution within the peripheral region of the semiconductor substrate.

6. The method according to claim 5, wherein the deposition of the thin film comprises depositing a fluoropolymer material, a spin-on carbon (SOC) material, a spin-on silicon carbide (SiC) material, or a spin-on self-assembled monolayer (SAM) within the peripheral region of the semiconductor substrate.

7. The method according to claim 5, wherein the discharge of the processing solution includes discharging a washing solvent, rinsing solvent, drying solvent, developing solvent, or etching solution into the central region of the semiconductor substrate.

8. The deposition of the thin film is carried out in a processing chamber including a front bevel nozzle, and the deposition of the thin film is The method according to claim 5, comprising depositing the material onto the annular portion of the front surface using the front bevel nozzle while spinning the semiconductor substrate at a certain rotational speed, thereby causing the deposited material to wrap around the side edge surface of the semiconductor substrate and cover the annular portion of the back surface.

9. The deposition of the thin film is carried out in a processing chamber including a back-side bevel nozzle, and the deposition of the thin film is The method according to claim 5, comprising depositing the material onto the annular portion of the back surface using the back bevel nozzle while spinning the semiconductor substrate at a certain rotational speed, thereby causing the deposited material to wrap around the side edge surface of the semiconductor substrate and cover the annular portion of the front surface.

10. The deposition of the thin film is carried out in a processing chamber including a back nozzle, and the deposition of the thin film is The method according to claim 5, comprising spinning the semiconductor substrate at a certain rotational speed and depositing the material on the back side of the semiconductor substrate near the center of the semiconductor substrate using the back nozzle, thereby covering the back surface and wrapping around the side edge surface of the semiconductor substrate to cover the annular portion of the front surface.

11. The discharge of the processing liquid is performed in the first processing chamber, and the method is The process further includes discharging the processing liquid onto the surface of the semiconductor substrate and then transferring the semiconductor substrate from the first processing chamber to the second processing chamber. The method according to claim 1, wherein the thin film is deposited on the surface of the semiconductor substrate so that the reservoir of the processing liquid is maintained within the central region of the semiconductor substrate during transport.

12. A method for cleaning the surface of a semiconductor substrate, wherein the method is The act of receiving the semiconductor substrate, wherein the semiconductor substrate has a front surface, a back surface, a side edge surface, a peripheral region, and a central region, the peripheral region includes the side edge surface and the annular portions of the front surface and the back surface adjacent to the side edge surface, and the central region extends from the center of the semiconductor substrate to the peripheral region, the act of receiving, The method of depositing a thin film on the surface of the semiconductor substrate, wherein the thin film is deposited only within the peripheral region of the semiconductor substrate and not within the central region, and the thin film has a lower surface energy than the surface of the semiconductor substrate. Discharging a cleaning solvent onto the surface of the semiconductor substrate after depositing the thin film, wherein the cleaning solvent is discharged into the central region of the semiconductor substrate over a first period of time while the semiconductor substrate is spinning, The cleaning solvent is discharged into the central region of the semiconductor substrate over a second period while the semiconductor substrate is stationary, thereby forming a reservoir of the cleaning solvent within the central region. Includes, A method to provide a low-energy surface in which the cleaning solvent is moved away from the peripheral region of the semiconductor substrate and the reservoir of the cleaning solvent is held within the central region of the semiconductor substrate by depositing the thin film on the surface of the semiconductor substrate.

13. The method according to claim 12, wherein the deposition of the thin film includes, using a spin-on process, covering the entire peripheral region with the thin film, including the side edge surface of the semiconductor substrate and the annular portions of the front surface and the back surface.

14. The method according to claim 12, wherein the deposition of the thin film comprises depositing a fluoropolymer material, a spin-on carbon (SOC) material, a spin-on silicon carbide (SiC) material, or a spin-on self-assembled monolayer (SAM) within the peripheral region of the semiconductor substrate.

15. After discharging the cleaning solvent into the central region of the semiconductor substrate over the second period, the method proceeds as follows: Discharge the cleaning solvent into the central region of the semiconductor substrate over a third period while the semiconductor substrate is spinning, The surface of the semiconductor substrate is rinsed with a rinsing solvent to remove the cleaning solvent from the surface of the semiconductor substrate. The semiconductor substrate is spun to dry the surface of the semiconductor substrate. The method according to claim 12, further comprising:

16. A method for cleaning the surface of a semiconductor substrate, wherein the method is The act of receiving the semiconductor substrate, wherein the semiconductor substrate has a front surface, a back surface, a side edge surface, a peripheral region, and a central region, the peripheral region includes the side edge surface and the annular portions of the front surface and the back surface adjacent to the side edge surface, and the central region extends from the center of the semiconductor substrate to the peripheral region, the act of receiving, The method of depositing a thin film on the surface of the semiconductor substrate, wherein the thin film is deposited only within the peripheral region of the semiconductor substrate and not within the central region, and the thin film has a lower surface energy than the surface of the semiconductor substrate. Discharging a first solvent onto the surface of the semiconductor substrate after depositing the thin film, wherein the first solvent is discharged into the central region of the semiconductor substrate while the semiconductor substrate is spinning in order to clean the surface of the semiconductor substrate, Discharging the first solvent and then discharging the second solvent onto the surface of the semiconductor substrate, wherein the second solvent is discharged into the central region of the semiconductor substrate while the semiconductor substrate is spinning in order to remove the first solvent from the surface of the semiconductor substrate, The method involves discharging a third solvent onto the surface of the semiconductor substrate after discharging the second solvent, wherein the third solvent is discharged into the central region of the semiconductor substrate while the semiconductor substrate is stationary, forming a reservoir of the third solvent within the central region. Includes, A method to provide a low-energy surface in which the third solvent is kept away from the peripheral region of the semiconductor substrate by depositing the thin film on the surface of the semiconductor substrate, thereby maintaining the reservoir of the third solvent within the central region of the semiconductor substrate.

17. The method according to claim 16, wherein the deposition of the thin film includes, using a spin-on process, covering the entire peripheral region with the thin film, including the side edge surface of the semiconductor substrate and the annular portions of the front surface and the back surface.

18. The method according to claim 16, wherein the first solvent is a cleaning solvent, the second solvent is a rinsing solvent, and the third solvent is a drying solvent.

19. The discharging of the first solvent, the discharging of the second solvent, and the discharging of the third solvent are carried out in the first processing chamber, and the method is Discharging the third solvent onto the surface of the semiconductor substrate to form a reservoir of the third solvent in the central region, and then transferring the semiconductor substrate from the first processing chamber to the second processing chamber. It further includes, The method according to claim 16, wherein the thin film is deposited on the surface of the semiconductor substrate so that the reservoir of the third solvent is maintained within the central region of the semiconductor substrate during transport.

20. The first processing chamber is a washing chamber, the second processing chamber is a supercritical processing chamber, and the method is The surface of the semiconductor substrate is made of supercritical carbon dioxide (CO2). ２ ) to be processed in this way, To dry the surface of the semiconductor substrate and The method according to claim 19, further comprising:

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