TWI502620B - Method for thinning a semiconductor workpiece - Google Patents

Description

Method of thinning semiconductor workpiece

The present invention relates to a method and apparatus for use with a workpiece, such as a semiconductor wafer, a flat panel display, a rigid magnetic or optical medium, a thin film magnetic head, or a microelectronic circuit, data storage element or layer formed therefrom, Or other workpiece formed by the substrate of the micromechanical component. These and similar items are collectively referred to herein as "wafers" or "workpieces." In particular, the present invention relates to methods and apparatus for thinning semiconductor workpieces.

State-of-the-art electronic devices such as mobile phones, personal digital assistants, and smart cards require thinner integrated circuit devices (ICDs). In addition, packages of advanced semiconductor devices, such as stacked dies or flip-chips, offer size packaging limitations that also require ultra-thin dies. In addition, as the operating rate of ICD continues to increase, heat dissipation becomes increasingly important. Much of this is due to the fact that ICDs operating at very high rates tend to generate a large amount of heat. Heat must be removed from the ICD to prevent device failure due to thermal stress and to prevent degradation of the frequency response due to reduced carrier mobility. One way to increase heat transfer away from the ICD and thereby mitigate any deleterious temperature effects is by thinning the semiconductor wafer from which the ICD is fabricated (making it thinner). Other reasons for thinning semiconductor wafers include optimization of signal transmission characteristics, formation of vias in the die, and minimization of the effects of thermal expansion coefficients between individual semiconductor devices and packages.

Semiconductor wafer thinning techniques have been developed in response to this increasing demand for smaller and higher performance ICDs. Typically, a semiconductor device is thinned while the device is in wafer form. The wafer thickness varies depending on the size of the wafer. For example, a 150 mm (mm) diameter germanium semiconductor wafer has a thickness of about 650 microns, while a wafer having a diameter of 200 or 300 mm is about 725 microns thick. Mechanically grinding the back side of a semiconductor is a standard method of thinning wafers. This thinning is called "back grinding." In general, the backgrinding process employs various methods to protect the front side or device side of the semiconductor wafer. The device side protection method of a conventional semiconductor wafer includes applying a protective tape or a photoresist layer to the device side of the wafer. The back side of the wafer is then ground until the wafer reaches the desired thickness.

However, conventional back grinding processes have disadvantages. Mechanical grinding induces stresses on the surface and edges of the wafer, including microcracks and edge debris. This induced wafer stress can cause performance degradation and wafer rupture, resulting in low yields. In addition, there is a limit to how much thinning can be used for semiconductor wafers using backgrinding. For example, a semiconductor wafer having a standard thickness (as described above) can generally be thinned to a range of approximately 250 to 150 microns.

Therefore, the wet chemical etching process is usually applied to the semiconductor wafer after the semiconductor wafer has been thinned by back grinding. This treatment is commonly referred to as stress relief etching, chemical thinning, chemical etching, or chemical polishing. The above process releases the induced stress in the wafer, removing the abrasive traces from the back side of the wafer and resulting in a fairly uniform wafer thickness. In addition, chemical etching after back grinding thins the semiconductor wafer beyond the capabilities of conventional back grinding. For example, using a wet chemical etch process after back grinding allows standard 200 and 300 mm semiconductor wafers to be thinned to 100 microns or less than 100 microns. Wet chemical etching typically involves exposing the back side of the wafer to an oxidizing/reducing agent (eg, HF (hydrofluoric acid), HNO ₃ (nitric acid), H ₃ PO ₄ (phosphoric acid), H ₂ SO ₄ (sulfuric acid)) or Exposure to a caustic solution (eg KOH (potassium hydroxide), NaOH (sodium hydroxide), H ₂ O ₂ (hydrogen peroxide)). An example of a wet chemical etch process can be found in U.S. Patent Application Serial No. 10/631,376, which is assigned to the assignee of the present application. The teachings of Application Serial No. 10/631,376 are incorporated herein by reference.

Although the method of thinning a semiconductor wafer is known, it is not without defects. For example, mounting a semiconductor wafer on a mounting or a so-called "chuck" so that the wafer can be thinned requires expensive coating and bonding equipment and materials, must have increased processing time, and must Subject to the possibility of introducing contaminants into the treatment area. In addition, the adhesive used to bond the wafer to the collet in the mechanical grinding process is not resistant to the chemical treatment fluid used in wet chemical etching. In addition, the use of current photoresists or adhesive tapes does not provide mechanical support for very thin wafers during backgrinding or subsequent handling and processing. The use of adhesive tape also creates obstacles in the removal process. For example, removal of the adhesive tape may expose the wafer to unwanted bending stresses. In the case of photoresist, the solvent is used to wash the material from the device side of the wafer, thereby increasing processing time and use of chemicals, and increasing the likelihood of contamination. The use of adhesive and protective polymers also creates high costs because of the necessity of equipment and materials to apply and remove the protective medium.

In addition, the thinned semiconductor wafer is susceptible to warping and bowing. Also, because the thinned semiconductor wafer can be extremely fragile, it is also susceptible to cracking when manipulated during further processing. Thinned semiconductor wafers (eg, below 250 microns) also present new problems in automated wafer handling because, in general, existing handling devices have been designed to conform to standard wafer thickness (eg 150mm wafers) 650 microns for 650 microns and 200 and 300mm wafers).

Therefore, there is a need for a method and apparatus for producing thinner semiconductor workpieces. At the same time, there is a need to provide thinner workpieces that are strong enough to minimize the risk of cracking but remain compatible with conventional automated semiconductor wafer handling equipment. Finally, it would be advantageous to develop a system that reduces the number of processing steps for thinning semiconductor workpieces.

The present invention provides systems, methods, and apparatus for processing semiconductor wafers. Innovative systems and equipment allow for the production of workpieces that are thin while maintaining strength and resistance to arc bending and warpage. As a result, the wafer produced by the method of the present invention is less susceptible to cracking. The method and apparatus of the present invention also provides improved article structure for manipulating thinned wafers while reducing the number of processing steps. This results in increased yield and improved processing efficiency as well as many other advantages.

In one aspect, the present invention provides a collet for receiving and supporting a semiconductor workpiece having a device side, a beveled portion, and a back side. The chuck has a body for supporting the workpiece; the holding member is removably attached to the body and becomes a peripheral portion covering the back side of the workpiece; and at least one sealing forming member is used for the holding member and the workpiece A seal is formed between the back sides. Due to its configuration, the collet allows the inner region of the back side of the workpiece to be exposed while protecting the peripheral portion of the back side of the workpiece. Then, the workpiece is thinned by a wet etching process. The result is a treated semiconductor workpiece having a thinned body (e.g., less than about 125 microns) and a thick rim (e.g., in the range of about 600 to 725 microns). The relatively thicker perimeter provides strength to the thinned workpiece and allows the workpiece to be manipulated by conventional automated handling equipment for additional processing.

In another aspect, the invention provides a semiconductor workpiece having a body and a perimeter comprised of a semiconductor material. The body is integrally joined to the periphery and has a thickness that is less than about 50% of the thickness of the perimeter. The relatively thick perimeter provides strength to the workpiece and prevents the body from bending and warping. At the same time, the body of the semiconductor workpiece can be thinned to a thickness of less than 300 microns, preferably less than 125 microns, more preferably less than 100 microns, especially less than 50 microns, and even less than 25 microns. The structural configuration of the thinned semiconductor workpiece of the present invention meets the industrial requirements for the thinned ICD required in today's latest electronic devices and advanced packaging technologies, while at the same time reducing the fragile state of the thinned workpiece. Risk of rupture.

The present invention also provides several methods of thinning semiconductor workpieces. In one aspect, the method includes the step of placing a semiconductor workpiece into a collet that covers a peripheral portion of the back side of the workpiece leaving about 95% of the backside surface of the workpiece exposed. The semiconductor workpiece is then thinned by a wet chemical etching process wherein the back side of the workpiece is exposed to an oxidant (eg, HF, HNO ₃ , H ₃ PO ₄ , H ₂ SO ₄ ) or exposed to a caustic solution (eg, KOH, NaOH) , H ₂ O ₂ ). During the wet chemical etching step, the exposed back side of the workpiece is thinned to a thickness less than 50% of the thickness of the workpiece prior to wet chemical etching. As a result, the periphery is formed at the periphery of the workpiece or as commonly referred to in the industry as an "exclusion zone". The circumference has a thickness substantially equal to the thickness of the workpiece prior to the wet chemical etching step (e.g., in the range of 600 to 725 microns). The remainder of the workpiece (ie, the thinned body) has a thickness that is less than 50% of the thickness of the perimeter (eg, less than 300 microns, preferably less than 125 microns, more preferably less than 100 microns, and especially less than 50 microns, And even less than 25 microns). This method eliminates the limitations associated with the known methods of thinning semiconductor workpieces described above while at the same time increasing overall manufacturing efficiency.

The invention also provides a method of thinning a batch of semiconductor workpieces. The method comprises the steps of placing a semiconductor workpiece into the chuck body such that the back side of the workpiece is exposed, inserting a batch of workpieces into the carrier assembly, loading the carrier assembly into the rotor assembly to cause the semiconductor workpiece to be Positioning to have an inclination, the rotating rotor assembly causes it to subsequently provide rotational motion to the carrier assembly and the workpiece therein, and to spray the treatment fluid onto the exposed back side of the workpiece. Through this system, the back side of the workpiece is thinned to a desired thickness (preferably less than 125 microns). After the workpiece is thinned, the disclosed implements and systems provide for rinsing and drying of the workpiece. The system also provides recycling and recovery of used process fluids.

To perform batch processing of semiconductor wafers, the present invention also provides a system including a processing chamber that allows the semiconductor workpiece to be wet chemically thinned to less than 125 microns in batches. The processing chamber includes a chamber body having a first end, an outer wall, and an opening at the first end that leads into a cavity. The processing chamber is supported within the processing machine to have an inclination, and the semiconductor workpiece within the processing chamber is similarly supported to have an inclination. The door assembly is disposed adjacent to the first end of the chamber body. The door assembly has a door that selectively closes the opening of the chamber body. The processing chamber also has a spray assembly having a nozzle for spraying a treatment fluid into the cavity of the chamber body and onto the exposed portion of the semiconductor workpiece therein. In an embodiment, the spray assembly has a dual inlet/outlet mechanism that introduces fluid from the opposite direction into the processing chamber.

According to another aspect, the processing chamber has an exhaust passage and an outlet or drain. The exhaust passage exhausts gases and vapors from the cavity of the process chamber. The drain removes excess of voids from the chamber body of the process chamber and used process fluid. A drain may be coupled to the recirculation system to deliver excess and used process fluid from the process chamber to the transfer tank.

According to another aspect, a system includes a carrier assembly that holds a plurality of workpieces. The carrier assembly is positioned in the cavity of the processing chamber and rotated within the processing chamber to allow the treated fluid to be sprayed to have a better coverage on the workpiece. In an embodiment, the carrier assembly has a plurality of positioning members of a length about its body. Positioning members are used to hold the semiconductor workpiece in a particular position in the carrier assembly and are used to provide clearance between adjacent semiconductor workpieces. Additionally, due to the geometry of the positioning member of the carrier assembly, the workpiece in the carrier assembly rotates with the carrier assembly and also rotates slightly independent of the rotation of the carrier assembly.

According to another aspect, the system includes a rotor assembly. The rotor assembly is positioned within the cavity of the process chamber and the carrier assembly is positioned within the cavity of the rotor assembly. A motor associated with the processing chamber drives the rotor assembly to rotate the rotor assembly within the cavity of the chamber body. The rotor assembly then provides rotational motion to the carrier assembly and the semiconductor workpiece therein.

Any of the aspects of the invention described may be combined and/or repeated one or more times to achieve optimal results. The invention also resides in sub-combinations of the described aspects. These and other objects, features and advantages of the present invention will become apparent from

A. Chuck for supporting semiconductor workpieces

Referring to Figures 1A through 1E, there is shown a collet 10 for supporting a semiconductor workpiece 50 during processing in accordance with an embodiment of the present invention. The collet 10 includes a support body 12, a retaining member 14, and sealing members 16, 24. The clasp 14 has two recesses or recesses 18. The sealing members 16, 24 are housed in two annular grooves 18, respectively. The clasp 14 is preferably in the form of a loop and is removably attached to the support body 12. In use, the workpiece 50 having the device side 51, the beveled portion (i.e., the peripheral edge) 52, and the back side 53 is placed on the support surface 28 of the support body 12 of the collet 50 below the device side 51 downwardly. . Then, the holding member 14 is attached to the outer periphery of the support body 12. As clearly shown in FIG. 1C, when the clasp 14 is joined to the support body 12, the clasp 14 wraps around the outer end of the support body 12 and covers the peripheral portion of the back side 53 of the workpiece 50, thereby stabilizing the workpiece 50. In the collet 10.

When engaged, the retaining member 14 preferably covers only a small peripheral portion of the back side 53 of the workpiece 50, leaving substantially the exposed side of the back side 53 of the workpiece 50 in an exposed state. In a preferred embodiment, the surface area of the back side 53 covered by the retaining member 14 extends inwardly from the beveled portion 52 by a distance of from about 1 to 10 mm (millimeters), more preferably between about 1 and 5 mm. And especially between about 2 and 4 mm. Preferably, at least 95% (or even 97% or 99%) of the surface area of the back side 53 of the workpiece 50 is in an exposed state. The exposed portion of the back side 53 of the workpiece 50 is then subjected to the treatment fluid and thinned to the desired thickness. Since the peripheral portion of the back side 53 of the workpiece 50 is covered during thinning, the process fluid cannot interact with the periphery of the back side 53 of the workpiece 50. Thus, the perimeter of the back side 53 of the workpiece 50 remains substantially the same in form, configuration, and thickness as before thinning. For the purposes of the present invention, the semiconductor material remaining at the periphery of the workpiece 50 after thinning is referred to as a rim. The periphery imparts strength to the thinned workpiece 50 and allows the automated handling device to manipulate the thinned semiconductor workpiece 50 processed in accordance with the present invention.

Turning to FIGS. 1D and 1E, in order to facilitate attachment of the clasp 14 to the support body 12, the clasp 14 has an engagement member 20 that cooperates with a recess 22 formed in the support body 12. In this way, a simple mechanical snap connection between the catch 14 and the support body 12 is achieved. Although not shown in FIGS. 1A through 1D, the present invention includes a joint member 20 extending from the support body 12 and cooperating with the recess 22 formed in the clasp 14 to removably connect the clasp 14 to the support body 12. configuration. In either configuration, the engagement member 20 and the recess 22 are preferably positioned between the first sealing member 16 and the second sealing member 24.

Referring to FIG. 1C, the clasp 14 has an outer peripheral end 30 having an angled surface 32. When the clasp 14 is attached to the support body 12, the inclined surface 32 of the outer peripheral end portion 30 of the clasp 14 matches the inclined surface 34 at the outer peripheral end of the support body 12 to form a notch 36. The notch 36 can accept a tool (not shown) to facilitate removal of the buckle 14 from the support body 12.

Turning now to Figure IE, the support body 12 has a lip or step 26 formed on its circumference. The lip 26 acts to align or guide the workpiece 50 as it is loaded into the collet 10. When properly aligned, the workpiece 50 will rest entirely on the support surface 28 of the support body 12. Although the collet 10 can be of any shape (e.g., square, rectangular, circular, etc.), as shown in Figures 1A through 1E, in the preferred embodiment, the collet is disc shaped and will have a slightly larger than that to be processed. The diameter of the diameter of the workpiece 50.

Referring now to Figures 2A and 2B, another embodiment of a collet 10 in accordance with the present invention is shown. Like the collet 10 shown in FIGS. 1A through 1E, the collet 10 includes a support body 12 and a retaining member 14. The retaining member 14 has first and second sealing members 16, 24 disposed within the annular recesses 18, 38. However, the mechanical attachment mechanism in the embodiment shown in Figures 2A and 2B is slightly different from the mechanism shown in Figures 1A through 1E. The joint member 20 extends from the outer periphery of the support body 12. The clasp 14 then has a recess 22 that cooperates with the engagement member 20 of the support body 12 to provide a simple snap-fit engagement of the clasp 14 to the support body 12. The upper portion of the clasp 14 including the sealing member 16 covers the exclusion zone of the back side 53 of the workpiece 50 at the engaged position. In the preferred embodiment, the retaining member 14 has a plurality of irrigation holes 40 for allowing treatment fluid to escape from the voids formed in the collet 10. The lower portion 42 of the buckle 14 that produces a mechanical snap-fit connection with the engagement member 20, together with the mating lower portion 46 of the support body 12, forms an annular recess 44. A tool (not shown) can be inserted into the annular recess 44 to allow the catch 14 to simply detach from the support body 12 of the collet 10 after processing is complete.

In an embodiment having two sealing members 16, 24 (as disclosed in Figures 1A-1E and 2A and 2B), the sealing member 16 creates a flexible interface and seal between the workpiece 50 and the retaining member 14 to The treatment fluid is prevented from accessing the device side 51 and the bevel portion 52 of the workpiece 50. This flexible interface also releases some of the stresses that are applied to the workpiece 50 during assembly and disassembly of the collet 10. The sealing member 24 creates a flexible interface between the clasp 14 and the support body 12 and also helps to relieve some of the stresses exerted on the workpiece 50 during assembly and disassembly of the collet 10.

Referring now to Figures 3A and 3B through Figures 7A and 7B, the design of various different collets 10 having only a single sealing member 16 is shown. In particular, Figures 3A and 3B show a collet 10 having a retaining member 14, a support body 12, and an engagement mechanism similar to the engagement mechanism illustrated in Figures 2A and 2B and described above. However, the retaining member 14 has only a single annular recess 18 that can receive the sealing member 16. In this embodiment, the annular groove 18 is V-shaped and receives a square compressible sealing member 16. Preferably, the square sealing member 16 has a semi-circular extension that projects from each corner to ensure proper assembly in the recess 18.

The collet 10 shown in Figures 4A and 4B and Figures 5A and 5B has an engagement ring 48 that is circumferentially attached to the outer periphery of the bottom of the support body 12. The engagement ring 48 extends radially outward from the support body 12, creating a stepped relationship between the support body 12 and the engagement ring 48, and forming the engagement member 20. The clasp 14 has a lower portion 42 that is formed with a U-shaped recess 22. The U-shaped recess 22 receives the joint member 20. The lower portion 42 of the clasp 14 has an extension portion 49 that wraps the engagement member 20 to form a mechanical snap connection between the clasp 14 and the engagement ring 48 of the support body 12. In Figures 4A and 4B, the retaining member 14 has two stepped annular recesses 18 that receive the sealing member 16, while the sealing member 16 has a first step for inserting the first step of the annular recess 18 The inner top portion has a second width for insertion into the bottom portion of the second step of the annular groove 18. In Figures 5A and 5B, the retaining member 14 has a single V-shaped annular recess 18 for receiving a sealing member 16 that is a compressible O-ring in this embodiment.

Figures 6A and 6B show another preferred embodiment of the collet 10 in accordance with the present invention. In this embodiment, the lower portion 42 of the retaining member 14 has an inner sidewall 60 having a convex projection 62 extending outwardly therefrom. The support body 12 has an end wall 64 having a concave recess 66 for receiving a raised projection 62 of the inner side wall 60 of the lower portion 42 of the retaining member 14. In this manner, the catch 14 engages the support body 12 and secures the workpiece 50 to the support surface 28 of the collet 10.

In embodiments having only a single sealing member 16 (as disclosed in Figures 3A and 3B to Figures 6A and 6B), the sealing member 16 creates a flexible interface between the workpiece 50 and the support body 12 to prevent treatment of fluids and workpieces. The device side 51 and the bevel 52 of 50 interact and release the stresses exerted on the workpiece during the assembly/disassembly process.

Turning now to Figures 7A and 7B, a preferred embodiment of the collet 10 incorporating the retaining member 14 and sealing member 16 of the prior embodiment is shown. In this embodiment, the retaining member 14 is a unitary, compressible annular ring having an annular groove 18 extending circumferentially through the middle of the retaining member 14. The support body 12 has an outer end 13 that is inserted into the annular groove 18 of the retaining member 14. The clasp 14 is maintained joined to the support body 12 due to the compressive force exerted by the clasp 14 on the support body 12 and the workpiece 50. In the attachment position, the outer peripheral portion (e.g., the exclusion region) of the workpiece 50 is also positioned within the annular groove 18. In the preferred embodiment, the retaining member 14 creates a seal with the back side 53 of the workpiece 50, thereby preventing process fluid from reaching the bevel 52 and the device side 51 of the workpiece 50 during processing.

Materials suitable for use in embodiments of the collet 10 in accordance with the present invention are discussed below. In general, the collet 10 can be made of several different polymeric materials that are stable and highly chemically resistant. Preferably, the support body 12 comprises polytetrafluoroethylene, and the fastening member 14 preferably comprises a fluoropolymer, such as polyvinylidene fluoride sold by Atofina Chemicals under the trade name KYNAR. ). In the embodiment illustrated in Figures 7A and 7B, the retaining member 14 preferably has a duometer hardness having a hardness less than that of the fluoropolymer but greater than the hardness of the elastomeric material discussed with respect to the sealing member. The material is formed. That is, it can be compressed to a material sufficient to form a seal with the workpiece 50 but strong enough to provide the buckle 14 with a structure for receiving the support body 12. In any embodiment of the present invention, in order to enhance the adhesion of the fastening member 14 to the support body 12, the support body 12 is preferably made of a durometer hardness having a hardness greater than that of the material forming the fastening member 14. Material composition.

As shown in FIGS. 1A to 1E, 2A and 2B, 5A and 5B, and 6A and 6B, the sealing members 16, 24 are preferably formed like "O-rings", but other shapes can also be used ( 3A and 3B and FIGS. 4A and 4B). The sealing members 16, 24 are preferably formed of a compressible material having a durometer hardness equal to or greater than 50. Specific examples of suitable elastomeric materials include perfluoroelastomers sold by DuPont under the trade name Kalrez, perfluoroelastomers sold by Greene, Tweed & Co. under the trade name Chemraz, by DuPont A fluoroelastomer sold under the trade name Viton, and a hydrocarbon elastomer sold under the trade name EPDM.

B. Method for thinning a single semiconductor workpiece

Turning now to the method of thinning a workpiece according to the present invention, FIG. 8 shows an embodiment of a method that can be implemented when the collet 10 and workpiece 50 described above are used to thin the back side 53 of the workpiece 50. At step 200, a workpiece 50 having a device side 51, a beveled portion 52, and a back side 53 is provided. The back side 53 of the workpiece 50 will have a given surface area depending on its size. Also, the workpiece 50 has a given thickness.

At step 210, the workpiece 50 is placed on the support surface 28 of the collet 10 directly below the support body 12 of the collet 10 on the device side 51. Attachment of the clasp 14 to the support body 12 is such that a peripheral portion of the back side 53 of the workpiece 50 (e.g., an exclusion region of the workpiece 50) is covered. In step 210, the workpiece 50 is secured to the collet 10. Due to the configuration of the collet 10, when the clasp 14 is attached to the support body 12, in step 220, the surface area of the back side 53 is substantially (and preferably at least 95%, more preferably At least 97%, and in particular at least 99%) are exposed while a small peripheral portion of the back side 53 of the workpiece 50 is covered.

The workpiece 50 is then thinned to a desired thickness at step 230 by applying a treatment fluid to the exposed back side 53 of the workpiece 50. Due to the overlapping configuration of the fasteners 14, by exposing the exposed back side 53 of the workpiece, at step 240, a peripheral edge and a body are formed on the workpiece 50. The circumference is formed at the outer periphery of the workpiece 50 and has a thickness RT, while the body of the workpiece 50 has a thickness MBT. In the preferred embodiment of Figure 8, the MBT is less than about 50% of RT. The desired MBT is preferably less than about 40% of RT, more preferably less than about 30% of RT, especially less than about 20% of RT, and even less than about 10% of RT. It should be understood that after thinning the workpiece 50, the RT should be approximately the same as the thickness of the workpiece 50 prior to the thinning process. Thus, for conventional 200mm and 300mm workpieces, the thinned RT is approximately 725 microns. Also, the conventional 150 mm workpiece has an RT of about 650 microns after thinning.

However, it is within the scope of the invention to process workpieces 50 that have previously been thinned by some other method, such as mechanical grinding. Thus, workpiece 50 having any thickness from 150 to 725 microns can be thinned in accordance with the present invention to produce workpiece 50 having a perimeter of thickness RT and a body of thickness MBT, where RT is substantially the same thickness as workpiece 50 The range (i.e., about 150 to 725 microns, even about 600 to 725 microns, or even about 300 to 725 microns), and the MBT is in the range of about 25 to 300 microns, preferably about 100 to 125. The range of microns, more preferably in the range of about 50 to 100 microns, especially in the range of about 25 to 50 microns.

Turning now to Figure 9, there is shown another embodiment of a method that can be implemented when the collet 10 described above is used to thin the workpiece 50. At step 300, a workpiece 50 having a thickness WPT is provided. The workpiece 50 has a device side 51, a beveled portion 52, and a back side 53. The workpiece 50 is placed on the collet 10 at step 310 directly below the support body 12 of the collet 10 on the device side 51. At step 320, the retaining member 14 is attached to the support body 12 such that a peripheral portion of the back side 53 of the workpiece 50 is covered. In this step, the workpiece 50 is fixed to the collet 10. Due to the configuration of the collet 10, when the clasp 14 is attached to the support body 12, the back side 53 of the workpiece 50 is substantially completely exposed except for the covered exclusion area.

Still referring to Figure 9, at step 330, the collet 10 and workpiece 50 are placed into a processing chamber. The processing chamber can be manual or automated, and is preferably in a spray acid tool platform, such as that available from Semitool, Inc. of Kalispell, Montana. Once inside the processing chamber, the processing fluid is applied to the exposed back side 53 of the workpiece 50 at step 340. The thinning process of step 340 preferably includes a conventional wet chemical etching process or a polishing process. In either treatment, the treatment fluid is preferably comprised of one or a combination of deionized water, hydrogen peroxide, ozone, potassium hydroxide, sodium hydroxide, hydrofluoric acid, nitric acid, sulfuric acid, citric acid, and phosphoric acid. A variety of other acidic and basic solutions can also be used depending on the particular surface to be treated and the material to be removed.

The treatment fluid can be applied to the workpiece 50 in any conventional manner. However, in the preferred embodiment, the treatment fluid is sprayed onto the back side 53 of the workpiece 50 via a nozzle or nozzles. In another preferred embodiment, the collet 10 and workpiece 50 are immersed in a volume of treatment fluid, or sequentially immersed in a plurality of identical treatment fluid volumes (at different concentrations or temperatures) or a plurality of different treatment fluid volumes.

Depending on the composition of the material to be removed and the amount of material to be removed (i.e., the desired final workpiece thickness), the treatment fluid will have the desired concentration, temperature, and flow rate. By monitoring and maintaining these process fluid variables, the process fluid can be applied to the exposed back side 53 of the workpiece 50 with a first etch rate and then applied at a second etch rate. Preferably, the first etch rate is greater than the second etch rate. That is, the semiconductor material is first quickly etched away and then etched away more slowly as the thickness of the workpiece 50 approaches the desired thickness.

Referring to step 350 of FIG. 9, the thinning process forms a perimeter 70 and a body 72 on the workpiece 50. The thinning process is performed until the body 72 reaches the desired thickness MBT. Preferably, the MBT is less than 50% of the WPT, more preferably less than 40% of the WPT, even more preferably less than 30% of the WPT, especially less than 20% of the WPT, and particularly preferably less than 10% of the WPT. It is preferred to measure the thickness of the body 72 of the semiconductor workpiece 50 during the entire thinning process. This can be achieved by using conventional infrared monitoring techniques in the processing chamber, or by any other known measurement technique such as capacitance measurement techniques. If desired, the above described process fluid variables can be adjusted based on continuous monitoring of the thickness of the workpiece.

At step 360, the thinned workpiece 50 is rinsed and dried. For example, the workpiece can be sprayed with a deionized water stream, a nitrogen stream, or a phosphoric acid stream during the rinsing step and then can withstand any one or more of the known drying techniques. Finally, the workpiece 50 is removed from the collet (step 370) and the thinned workpiece 50 is diced into a plurality of dies (step 380).

C. Batch processing chambers and systems for thinning semiconductor workpieces

Thinning of the semiconductor workpiece 50 in accordance with the present invention can be performed on a single workpiece 50 or simultaneously on a plurality of workpieces 50. When thinning a plurality of workpieces 50, it is desirable to place each of the workpieces 50 into the corresponding collet 10, and then place the plurality of collets 10 and the workpiece 50 into a carrier, such as in a joint review. The carrier disclosed in U.S. Patent Application Serial No. 10/200,074, the entire disclosure of which is incorporated herein by reference. Once the plurality of workpieces 50 (and associated collet 10) are placed into the carrier, the carrier is loaded into the processing vessel and the processing fluid is applied to the exposed back side 53 of the plurality of workpieces 50. To ensure proper application of the treatment fluid to the workpiece 50, it is preferred to rotate the collet 10 or carrier within the processing vessel or both during processing. The processing vessel can be a stand-alone implement or one of a plurality of workstations that make up a larger workpiece handling system.

Referring now to Figures 12, 13, and 27, there is shown a machine or implement 410 for processing a workpiece 412. The implement 410 preferably includes a housing 414 that houses the first processing module 416 and the second processing module 418, but it is understood that additional slots or modules in operation may also be disposed in the implement 410. The first processing module 416 is typically a processing chamber that thins the semiconductor workpiece 412, such as the processing chamber 420 shown in FIG. 14, and the second processing module 418 is typically dried after the workpiece 412 has been thinned and The drying and rinsing chamber 422 of the workpiece 412 is rinsed. The implement 410 also has an electronic control area 425 that is associated with devices such as the control panel 424, the display 426, and a processor for controlling and monitoring the operation of the system. In addition, the implement 410 has another module 427 that houses a tank in progress. Other features and components of the system are detailed below.

As explained above, in this system, a plurality of workpieces 412 are thinned in the processing chamber 420. In the preferred embodiment, each workpiece 412 is mounted to a respective collet 430 for processing prior to being placed into processing chamber 420. The configuration between the workpiece and the various collet configurations has been described in detail above with respect to Figures 1-7. A plurality of installed workpieces are then placed into the carrier assembly 452 for holding the plurality of workpieces 412. Referring to Figures 15 and 16, the carrier assembly 452 substantially holds the workpiece 412 about the peripheral portion of the workpiece. In this embodiment, the carrier assembly 452 includes a first carrier member 454 and a second carrier member 456 that are interconnected to form the entire carrier assembly 452. Approximately 25 workpieces 412 can be held within this carrier assembly 452. Each of the carrier members 454, 456 has a plurality of support legs 458 to provide rigidity to the carrier assembly 452. In the preferred embodiment, as shown in FIG. 15, each of the carrier members 454, 456 has four radially extending and substantially equally spaced apart support legs 458. The spacing between the support legs 458 allows the process fluid to reach the workpiece 412 in the process chamber 420. Additionally, the support legs 458 have a plurality of through openings 460 to reduce the weight of the carrier members 454, 456. As shown in FIG. 15, the first and second engagement members 457, 459 extend from the carrier assembly 452 when the first and second carrier members 454, 456 are coupled. The engagement members 457, 459 cooperate with a rotor assembly 474 (described below) to positionally retain the carrier assembly 452 within the rotor assembly 474.

Carrier assembly 452 has a central bore region 462. At the periphery of the central bore region 462, the carrier assembly 452 has a plurality of locating members 464 that position and hold the semiconductor workpiece 412 within the carrier assembly 452. The positioning member 464 extends generally radially inward from the support leg 458. As such, the positioning member 464 provides a gap between adjacent workpieces 412 in the carrier assembly 452 to allow the processing fluid to interact with the entire back side of the workpiece 412. As best shown in FIG. 16, the positioning member 464 facilitates holding the workpiece 412 mounted to the collet 430 as described above on the edge in the carrier assembly 452. However, the geometry of the positioning member 464 generally allows the workpiece 412 to be slightly free to move in both the axial and rotational directions when positioned in the carrier assembly 452. As such, the workpiece 412 can rotate slightly independently within the carrier assembly 452. Carrier assembly 452 is typically made of Teflon or stainless steel. In a preferred embodiment, the carrier assembly is made of polytetrafluoroethylene.

Another carrier assembly 466 is shown in FIG. In this embodiment, the carrier assembly 466 has a first end plate 468, a second end plate 470, and a plurality of joining members 472 extending between the first end plate 468 and the second end plate 470. At least one of the joint members 472 has a locating member 464 depending therefrom that extends from the radially inward direction to position and retain the workpiece 412 within the carrier assembly 466. As in the carrier assembly 452 described above, the positioning member 464 in the carrier assembly 466 helps to secure the workpiece 412 secured to the collet 430 in the carrier assembly 466 on the edge. Additionally, as in the carrier assembly described above, the positioning member 464 allows the workpiece 412 to be slightly free to move in both the axial and rotational directions when positioned in the carrier assembly 466. The carrier assemblies 452, 466 can be used to process workpieces 412 having a variety of different sizes, but are typically formed to process a workpiece 412 of a certain size, such as a 200 mm or 300 mm diameter semiconductor wafer.

After a suitable carrier assembly (for purposes of example, this disclosure will use carrier assembly 452 in further discussion herein), after carrying workpiece 412, it is assembled to cavity 506 contained in processing chamber 420. The rotor assembly 474. An example of a rotor assembly 474 is shown in Figures 18 and 19, and an example of a rotor assembly 474 carrying a carrier assembly 452 is shown in Figure 14. The rotor assembly 474 generally includes a generally cylindrical rotor 476, a generally circular base plate 478, and a drive shaft 480. The rotor 476 has an outer ring 482, a base 484, and a plurality of connecting members 486 extending between the base 484 and the outer ring 482. The void 488 is defined within the interior of the base 484, between the connecting member 486, and the outer ring 482. The shape of the cavity 488 becomes an acceptable carrier assembly 452. Drive shaft 480 is coupled to drive plate 490 that rotates with drive shaft 480. A plurality of auxiliary drive rods 492 are in turn coupled to drive plate 490. Drive rod 492 extends through connecting member 486 to assist in driving rotor assembly 474. Typically, rotor 476 is made of polytetrafluoroethylene, but other materials are also acceptable. In addition, in order to maintain sufficient rigidity but reduce weight, the auxiliary drive rod 492 is made of carbon graphite. Drive shaft 480 and drive plate 490 are typically made of stainless steel or some other suitable material. Seal 494 is used to ensure that process fluid does not enter the internal components of rotor assembly 474.

Referring to Figures 14 and 22, the carrier assembly 452 is loaded into a rotor assembly 474 in the cavity 506 of the process chamber 420. The processing chamber 420 includes a chamber body 496 having a first end 498, a second end 500, an outer wall 502, and a void leading to the processing chamber 420 at the first end 498 of the chamber body 496. An opening 504 in 506. The cavity 506 is shaped to accommodate a rotor assembly 474 that is loaded with a carrier assembly 452 carrying a plurality of workpieces 412. The chamber body 496 can have a split ring assembly 497 that is coupled to the first end 498 of the chamber body 496. In the preferred embodiment, the chamber body 496 is made of a thick (e.g., about 25 mm thick) polytetrafluoroethylene. This material is inert to the various aggressive and corrosive etchants used in the etching/thinning process. However, it is understood that other materials that provide similar qualities can also be used. Alternatively, the processing chamber 420 can have a liner 507 made of such a material.

The processing chamber 420 also has various different assemblies coupled thereto, including a door assembly 508 and a motor assembly 512. As shown in Figures 14 and 21, the motor assembly 512 generally includes a motor 514 and a mounting plate 516. Motor 514 is coupled to mounting plate 516, which in turn is coupled to second end 500 of chamber body 496 of processing chamber 420. In the preferred embodiment, motor 512 is a brushless D.C. (direct current) servo motor. As shown in FIG. 23, the drive shaft 480 of the rotor assembly 474 extends to the exterior of the process chamber 420 and through the opening 518 of the second end 500 of the chamber body 496. Drive shaft 480 is inserted into motor 514 to allow motor 514 to drive drive shaft 480 (i.e., to provide rotational motion to drive shaft 480). Thus, via the drive shaft 480 of the rotor assembly 474, the motor 514 can rotate the carrier assembly 452 and the workpiece 412 therein.

The processing chamber 420 also includes a spray assembly 510 that injects process fluid into the processing chamber. In the preferred embodiment, the spray assembly 510 is integral with the processing chamber 420. In the preferred embodiment illustrated in Figures 14 and 20-24, the spray assembly 510 has a pair of dual overlapping spray manifolds 520 to provide a more uniform transfer of process fluid. A plurality of nozzles 522 within each of the manifolds 520, and a plurality of openings 525, and processing fluid is sprayed from the nozzles 522 through the openings 525 into the processing chamber 420. Manifold 520 receives process fluid from transfer trough 546 at inlet port 521 and distributes the process fluid along manifolds 520 over a plurality of nozzles 522, as shown in FIG. Nozzle retainer 524 covers nozzle 522. The nozzle 522 sprays process fluid into the cavity 506 of the process chamber 420 and onto the exposed portion of the workpiece in the carrier assembly 452 as the workpiece is rotated by the rotor assembly 474.

In the preferred embodiment, each of the manifolds 520 has an inlet port 521 at both the first end 498 and the second end 500 of the process chamber 420, and generally along the entire process chamber 420 A nozzle 522 that extends in length. This provides a dual treatment fluid inlet in the opposite direction of the manifold 520. By having a dual process fluid inlet in the manifold 520, the pressure drop across the manifold 520 is reduced and the flow or volume of fluid that can be introduced into the process chamber 420 is increased.

Referring to FIG. 20, the door assembly 508 extends adjacent the first end 498 of the chamber body 496 to provide access to the voids 506 of the processing chamber 420. Door assembly 508 preferably forms a seal with first end 498 of processing chamber 420. As shown in FIG. 20, the door assembly 508 generally includes a support plate 526, a front panel 528, a door 530, and a pair of linear tracks or guides 532. In the preferred embodiment, linear track 532 includes a linear actuator. A support plate 526 is coupled to the chamber body 496 to secure the door assembly 508 to the process chamber 420. The front panel 528 extends below the support plate 526 and provides support for the lower end of the linear actuator 532. The linear actuator 532 supports the door 530 and is configured to allow the door 530 to sealably close the first position of the opening 504 leading to the cavity 506 of the chamber body 496 from the door 530 to the point where the cavity 506 can be accessed Two positions (as shown in Figure 20). Door 530 may also have a window 534 for permitting visual inspection of processing chamber 420.

As best shown in FIG. 13, the process chamber 420 is secured within the chassis 414 of the machine 410 at an oblique angle. In the preferred embodiment, the processing chamber 420 has mounting members 536 on the sides of the chamber body 496. Mounting member 536 cooperates with a receiving member (not shown) of machine 410 to support processing chamber 420. In this embodiment, the mounting member 536 operates as a male mating member and the receiver operates as a female mating member. However, it will be appreciated that other types of mounting may be possible without departing from the scope of the invention, including the mounting member 536 on the chamber body 496 being a female and the receiving member of the machine 410 being a male.

Although the processing chamber 420 can be oriented horizontally, it is preferably oriented at an oblique angle. Additionally, in the preferred embodiment, the first end 498 of the chamber body 496 is angled upward at an angle of, for example, 5 to 30 degrees, and is optimal at about 10 degrees such that the first end 498 of the process chamber 420 is Higher than the height of the second end 500 of the process chamber 420. To achieve this orientation, in the preferred embodiment, the receiving member of the chassis 414 is configured to have a suitable angle of inclination. The chamber body 496 of the processing chamber 420 is coupled to the receiver via the mounting member 536 as described above. It can be appreciated that the semiconductor workpiece will thus be positioned to have substantially the same angle of inclination as the process chamber 420.

As shown in Figures 21 through 23, the processing chamber 420 has an exhaust passage 540 and an outlet or drain 542. The exhaust passage 540 discharges gas and vapor from the cavity 506 of the process chamber 420 and discharges it out of the vent outlet 541. In the preferred embodiment, the exhaust passage 540 extends approximately the entire length of the chamber body 496. The drain 542, in the preferred embodiment, includes a drain chute that extends approximately the entire length of the chamber body 496 to drain and drain the used process fluid and removed helium to the exterior of the process chamber 420. . As shown in FIG. 22, the exhaust passage 540 can be located in the chamber body portion opposite the drain 542. The drain 542 has a drain outlet 543 coupled to the recirculation system 544 to drain excess and spent process fluid and helium from the cavity 506 of the chamber body 496 of the process chamber 420. The recirculation system 544 typically delivers excess and used process fluid from the process chamber to a suitable transfer tank 456. Additionally, the process fluid and the removed helium may be drained to the exterior of the process chamber 420 to be discarded rather than recycled. Exhaust passage 540 and drain 542 are formed to remove excess/used process fluid and plume from the process chamber in a single pass. The smoke is discharged upward to the outside of the exhaust passage 540, and the used treatment fluid and helium are drained down to the outside of the drain 542.

In a preferred embodiment, the treatment fluid used in the system of the present invention comprises one of water, hydrogen peroxide, ozone, potassium hydroxide, sodium hydroxide, hydrofluoric acid, nitric acid, sulfuric acid, citric acid, and phosphoric acid or A variety. Other treatment fluids are also available. The treatment fluid can be mixed and adjusted to meet the specific needs of the system.

A volume of process fluid is typically contained in transfer trough 546 for transfer to process chamber 420. However, additional components can be provided as part of the overall system to transfer fluid from the transfer tank 546 to the process chamber 420. An example of a fluid transfer design is shown in FIG. In this example, pump 548 is used to pump process fluid from transfer tank 546 to process chamber 420. A filter 550 is disposed between the transfer tank 546 and the process chamber 420 to filter the process fluid. Additionally, a concentration monitor 552 can be disposed between the transfer tank 546 and the process chamber 420 to monitor the concentration of process fluid being delivered to the process chamber 420. Finally, flow meter 554 is used to monitor the volume of process fluid delivered to process chamber 420. Heat exchanger 556 can also be provided in connection with transfer tank 546 to regulate the temperature of the process fluid. These components are typically housed throughout the implement 410.

The system can also include a concentrated metering vessel 558 that contains a concentrated volume of various processing fluids. For example, as shown in FIG. 26, three metering containers 558 are provided. In this example, one metering container holds hydrofluoric acid, another metering container holds nitric acid, and another metering container holds phosphoric acid. Each metering container 558 typically has its own metering pump 560 to deliver a particular process fluid from the metering container 558 to the transfer tank 546. Depending on the concentration of treatment fluid typically determined by concentration monitor 552, one or more of metering pumps 560 can suitably dispense the treatment fluid pool in transfer tank 546 to maintain the desired fluid concentration. The metering container 558 can be housed within the implement 410 or external to the implement, while fluid is pumped into the implement 410 via the metering pump 560.

As explained below in the method of processing a workpiece, various cleaning and etching steps are provided. Separate transfer slots 546 are typically provided for each step. Thus, the processing fluid required for the pre-cleaning step 612 can be contained in a transfer tank 546, and the processing fluid required for the rough etching step 614 can be contained in a separate transfer tank 546, and the processing fluid required for the polishing step 616 is polished. The processing fluid required for the rinsing step 618 can be contained in yet another separate transfer slot 546. Thus, metering container 558 can be used to separately transfer fluid to a suitable transfer slot 546 (only one transfer slot is shown in Figure 26). In addition, the recirculation system delivers excess and used process fluid from the process chamber to the appropriate transfer tank 546 in accordance with current processing steps.

D. Method of thinning a batch of semiconductor workpieces

A method for processing a batch of semiconductor workpieces is shown in FIG. As shown, the first step 600, often performed while processing the workpiece, is to place the workpiece 412 into the collet 430 under the back side of the workpiece 412. The second step 602 includes loading the workpiece 412 (which has been in the collet 430) between the carrier assembly 452 and the positioning member of the carrier assembly. After the carrier assembly 452 is fully loaded with a plurality of workpieces 412 (typically 25 to 50 workpieces), the carrier assembly 452 is placed into the rotor assembly within the cavity 506 of the processing chamber 420 in step 604. 474. After the workpiece 412 is loaded into the rotor assembly 474 in the process chamber 420, the door 530 is moved to the first position to sealingly close the opening 504 of the chamber body 496 leading to the cavity 506 (step 608).

After the workpiece 412 is placed into the cavity 506 and the door 530 of the process chamber 420 is closed, the workpiece is ready to be processed. Typically, workpiece 412 is processed while rotating processing chamber 420. Accordingly, at step 610, the motor 514 is charged to rotate the rotor assembly 474 within the process chamber 420. The workpiece 412 rotates with the carrier assembly 452 in the rotor assembly 474, but the workpiece 412 also rotates slightly and independently axially as explained above. Second, the process fluid is sprayed onto the exposed portion of the workpiece in the carrier assembly 452 via the nozzle 522 of the spray assembly 510 as the workpiece is rotated by the rotor assembly 474.

In an embodiment, a first pre-cleaning spray step is performed (step 612). In this step 612, the cleaning fluid is sprayed through the spray assembly 510 and onto the exposed portion of the workpiece 412 in the process chamber 420 to remove surface contamination on the workpiece 412. The cleaning solution is contained in the first transfer tank and may contain at least one of H ₂ O (water), H ₂ O ₂ , and NH ₄ OH (ammonium hydroxide). Next, a first coarse chemical etch is performed at step 614. In the first chemical etch step, an increased etch rate is used to remove a larger amount of substrate from the workpiece 412. After a rough chemical etch is performed on the workpiece 412, a polishing chemical etch is performed on the workpiece 412 at step 616. The etching rate of the polishing chemical etching is smaller than the etching rate of the coarse chemical etching. In a preferred embodiment, the step of chemically etching the workpiece 412 includes applying a solution of HF, HNO ₃ , and H ₃ PO ₄ to the workpiece 412. Two different transfer channels are used to contain the fluid for the rough and polishing etch process. Through this two steps, the batch of workpieces 412 are thinned in the processing chamber 420. The workpiece 412 can be thinned to a thickness of less than 100 microns. Next, workpiece 412 is rinsed in process chamber at step 618. Rinsing the workpiece 412 generally comprises H ₃ PO ₄ solution was applied to the processing chamber 420 of the workpiece 412. This solution is contained in another transfer tank 546. During each of these steps, the spent process fluid is typically recovered via recycle system 544 and transferred from process chamber 420 to appropriate transfer tank 546.

After the workpiece 412 has been thinned and rinsed, the workpiece is typically removed from the process chamber 420 at step 620. In general, workpiece 412 is maintained in carrier assembly 452 and carrier assembly 452 is removed from rotor assembly 474 in processing chamber 420. At step 624, the carrier assembly 452 holding the workpiece 412 is placed into the second processing module 418 for drying and rinsing. The step of drying and rinsing the workpiece 412 in the drying and rinsing chamber 422 generally involves first applying deionized water to the workpiece 412 to rinse the workpiece 412, and then applying isopropyl alcohol vapor or hot nitrogen to the workpiece to dry the workpiece. 412, this is done below the rotating workpiece 412. Each of these fluids can be housed in another transfer tank, and after the workpiece 412 has been cleaned and dried, the carrier assembly 452 is removed from the second process chamber 422 in step 626. At step 628, the workpiece 412 is removed from the carrier assembly 452, and finally at step 630, the workpiece 412 is removed from the collet 430.

E. Thinned semiconductor workpiece

Referring now to Figures 10 and 11, the resulting thinned semiconductor workpiece 50 is processed in accordance with the method of the present invention. As described above, the thinned workpiece 50 includes a perimeter 70 and a body 72. A peripheral edge 70 is formed at the periphery of the workpiece 50 and is integral with the body 72. In general, when processing a standard semiconductor workpiece 50, the processed workpiece 50 will have a body 72 having a thickness of less than 125 microns and a perimeter 70 having a thickness in the range of about 600 to 725 microns. However, in a preferred embodiment, body 72 will have a thickness of less than 100 microns, preferably less than 50 microns, and especially less than 25 microns. As described above, the peripheral edge 70 is formed at the exclusion region of the workpiece 50, and may have a width in the range of 1 to 10 mm (shown as w in FIG. 10), preferably in the range of 1 to 5 mm, and Especially in the range of 1 to 2 mm. The body 72 and the peripheral edge 70 are formed of the same material as the workpiece 50 before thinning. Most preferably, the body 72 and the peripheral edge 70 are constructed of tantalum.

As also mentioned above, the workpiece 50 which has previously been thinned by another method can also be thinned in accordance with the present invention. In these cases, the initial thickness of the workpiece 50 to be thinned according to the present invention may be 200 microns or less. In this case, the body 72 of the workpiece 50 that is thinned according to the present invention will have a thickness that is less than about 50% of the thickness of the peripheral edge 70, preferably less than about 40% of the thickness of the peripheral edge 70, and more preferably less than the circumference. 30% of the thickness of 70, particularly preferably less than 20% of the thickness of the peripheral edge 70, is even less than 10% of the thickness of the peripheral edge 70, and in particular less than 5% of the thickness of the peripheral edge 70. The invention can also be used to thin workpieces 50 having different sizes. Thus, the perimeter 70 would preferably comprise less than about 5% of the surface area of the surface area (BSSA) of the back side 53 of the workpiece 50, more preferably less than 3% of the BSSA, and even less than 1% of the BSSA.

Numerous modifications of the invention described above are possible without departing from the basic teachings of the invention. Although the present invention has been described in detail with reference to the specific embodiments thereof, it will be understood by those skilled in the art that the present invention may be modified without departing from the scope and spirit of the invention.

10. . . Chuck

12. . . Support body

13. . . Outer end

14. . . Holder

16. . . Sealing member

18. . . Groove or recess

20. . . Joint member

twenty two. . . Concave

twenty four. . . Sealing member

26. . . Lip or step

28. . . Support surface

30. . . Outer peripheral end

32. . . Inclined surface

34. . . Inclined surface

36. . . gap

38. . . Groove

40. . . Flush hole

42. . . Lower part

44. . . Annular recess

46. . . Lower part

48. . . Joint ring

49. . . Extended part

50. . . Semiconductor workpiece

51. . . Device side

52. . . Tapered part (peripheral edge)

53. . . Dorsal side

60. . . Inner side wall

62. . . Protruding projection

64. . . End wall

66. . . Concave recess

70. . . Periphery

72. . . main body

200. . . step

210. . . step

220. . . step

230. . . step

240. . . step

300. . . step

310. . . step

320. . . step

330. . . step

340. . . step

350. . . step

360. . . step

370. . . step

380. . . step

410. . . Machine or machine

412. . . Workpiece

414. . . Chassis

416. . . First processing module

418. . . Second processing module

420. . . Processing chamber

422. . . Drying and rinsing chamber

424. . . control panel

425. . . Electronic control area

426. . . monitor

427. . . Module

430. . . Chuck

452. . . Carrier assembly

454. . . First carrier member

456. . . Second carrier member

457. . . First joint member

458. . . Support leg

459. . . Second joint member

460. . . Opening

462. . . Center drilling area

464. . . Positioning member

466. . . Carrier assembly

468. . . First end plate

470. . . Second end plate

472. . . Connecting member

474. . . Rotor assembly

476. . . Rotor

478. . . Base plate

480. . . Drive shaft

482. . . Outer ring

484. . . Base

486. . . Connecting member

488. . . Hole

490. . . Driver board

492. . . Auxiliary drive rod

494. . . Seals

496. . . Room body

497. . . Split ring assembly

498. . . First end

500. . . Second end

502. . . Outer wall

504. . . Opening

506. . . Hole

507. . . lining

508. . . Door assembly

510. . . Spray assembly

512. . . Motor assembly

514. . . motor

516. . . Mounting plate

518. . . Opening

520. . . Manifold

521. . . Entrance port

522. . . nozzle

523. . . Nozzle receptacle

524. . . Nozzle retaining member

525. . . Opening

526. . . Support plate

528. . . Front panel

530. . . door

532. . . Linear track or guide, linear actuator

534. . . window

536. . . Mounting member

540. . . Exhaust passage

541. . . Ventilation outlet

542. . . Export or drain

543. . . Drainage outlet

544. . . Recirculation system

546. . . Transfer slot

548. . . Pump

550. . . filter

552. . . Concentration monitor

554. . . Flow meter

556. . . Heat exchanger

558. . . Metering container

560. . . Metering pumps

600. . . First step

602. . . Second step

604. . . step

608. . . step

610. . . step

612. . . Pre-cleaning step

614. . . Rough etching step

616. . . Polishing etching step

618. . . Flushing step

620. . . step

624. . . step

626. . . step

628. . . step

630. . . step

MBT, RT, WPT. . . thickness

w. . . width

1A is a perspective view of a collet in accordance with the present invention in which a semiconductor workpiece prior to thinning is fixed.

Figure 1B is a cross-sectional view of the collet and workpiece shown in Figure 1A.

Figure 1C is a partial enlarged view of the collet and workpiece shown in Figure 1B showing the cooperation between the collet and the workpiece.

Figure 1D is an exploded cross-sectional view of the collet and workpiece shown in Figure 1A.

Figure 1E is a partial enlarged view of the collet and workpiece portion indicated by X in Figure 1D.

2A is a cross-sectional view of another embodiment of a collet in accordance with the present invention in which a workpiece prior to thinning is secured.

Figure 2B is a partial enlarged view of the collet and workpiece shown in Figure 2A showing the cooperation between the collet and the workpiece.

3A is a cross-sectional view of another embodiment of a collet in accordance with the present invention in which a workpiece prior to thinning is secured.

Figure 3B is a partial enlarged view of the collet and workpiece shown in Figure 3A showing the cooperation between the collet and the workpiece.

4A is a cross-sectional view of another embodiment of a collet in accordance with the present invention in which a workpiece prior to thinning is secured.

Figure 4B is a partial enlarged view of the collet and workpiece shown in Figure 4A showing the cooperation between the collet and the workpiece.

Figure 5A is a cross-sectional view of another embodiment of a collet in accordance with the present invention with the workpiece prior to thinning secured.

Figure 5B is a partial enlarged view of the collet and workpiece shown in Figure 5A showing the cooperation between the collet and the workpiece.

Figure 6A is a cross-sectional view of another embodiment of a collet in accordance with the present invention with the workpiece prior to thinning secured.

Figure 6B is a partial enlarged view of the collet and workpiece shown in Figure 6A showing the cooperation between the collet and the workpiece.

Figure 7A is a cross-sectional view of an embodiment of a collet in accordance with the present invention with the workpiece prior to thinning secured.

Figure 7B is a partial enlarged view of the collet and workpiece shown in Figure 7A showing the cooperation between the collet and the workpiece.

8 and 9 are flow diagrams showing aspects of the process of the method in accordance with the present invention.

Figure 10 is a perspective view of a semiconductor workpiece that is thinned in accordance with the method of the present invention.

Figure 11 is a cross-sectional view of the thinned semiconductor workpiece shown in Figure 10.

Figure 12 is a perspective view of an implement for processing a semiconductor workpiece.

Figure 13 is a perspective view of the implement of Figure 12 with the panel removed to reveal the tilting station in the implement.

Figure 14 is an exploded perspective view of an embodiment of a processing chamber used in the workstation of the implement of Figure 12;

15 is a perspective view of an embodiment of a carrier assembly for use with a processing chamber.

Figure 16 is a cross-sectional side view of the carrier assembly taken along line A-A of Figure 15.

17 is a perspective view of another embodiment of a carrier assembly for use with the processing chamber of FIG.

Figure 18 is a front perspective view of the rotor assembly used in the workpiece processing system.

Figure 19 is a rear exploded perspective view of the rotor assembly of Figure 18.

Figure 20 is a front perspective view of the process chamber of Figure 14.

21 is a rear perspective view of the process chamber of FIG. 14.

Figure 22 is a rear cross-sectional view of the process chamber of Figure 21.

23 is a cross-sectional side view of the venting and draining assembly of the processing chamber of FIG. 21.

Figure 24 is a cross-sectional side view of the processing chamber of Figure 21 through the spray assembly.

Figure 25 is a flow chart showing a one-way method for thinning a workpiece in a processing chamber.

Figure 26 is a streamline diagram showing a single pass fluid transfer design.

Figure 27 is a schematic illustration of an implement incorporating the processing chamber of Figure 14.

200. . . step

210. . . step

220. . . step

230. . . step

240. . . step

Claims (30)

A method of thinning a back side of a semiconductor workpiece having a surface area BSSA, the method comprising the steps of: placing the semiconductor workpiece into a chuck, the chuck covering the back side of the workpiece a peripheral portion leaving at least 95% of the BSSA in an exposed state; and thinning the exposed portion of the back side of the workpiece to produce a perimeter having a thickness RT and having a thickness less than about 50% of the RT main body. The method of claim 1, wherein the body has a thickness less than about 40% of the RT. The method of claim 1, wherein the body has a thickness less than about 30% of the RT. The method of claim 1, wherein the body has a thickness less than about 20% of the RT. The method of claim 1, wherein the body has a thickness less than about 10% of the RT. The method of claim 1, wherein at least 97% of the BSSA is in an exposed state. The method of claim 1, wherein at least 99% of the BSSA is in an exposed state. The method of claim 1, wherein the circumference is formed at a periphery of the workpiece. The method of claim 1, wherein the RT is in the range of 200 to 725 microns. The method of claim 9, wherein the body has a thickness in the range of about 100 to 120 microns. The method of claim 9, wherein the body has a thickness in the range of about 50 to 100 microns. The method of claim 9, wherein the body has a thickness in the range of about 25 to 50 microns. The method of claim 1, wherein the body has a thickness in the range of about 100 to 120 microns. The method of claim 1, wherein the body has a thickness in the range of about 50 to 100 microns. The method of claim 1, wherein the body has a thickness in the range of about 25 to 50 microns. A method of thinning a back side of a semiconductor workpiece having a thickness WPT, the method comprising the steps of: placing the semiconductor workpiece on a chuck body such that the back side of the workpiece is exposed; and a holding member Attached to the collet body such that the workpiece is fixed to the collet body, and a peripheral portion of the back side of the workpiece is covered by the clasp; and the exposed portion of the back side of the workpiece is thinned, To create a perimeter and a body portion, the body portion has a thickness MBT that is less than 50% of the WPT. The method of claim 16, wherein the step of thinning the exposed portion of the back side of the workpiece comprises from the back side of the workpiece The exposed portion of the chemical etch removes the semiconductor material. The method of claim 17, wherein the step of thinning the exposed portion of the back side of the workpiece further comprises the step of polishing the exposed portion of the back side of the workpiece. A method of thinning a back side of a semiconductor workpiece having a thickness WPT, the method comprising the steps of: placing the semiconductor workpiece on a chuck that surrounds a peripheral portion of the back side of the workpiece to make the workpiece a body portion of the back side is exposed; the chuck and the workpiece are placed in a processing chamber; and the exposed portion of the body of the processing fluid on the back side of the workpiece is applied to thin the body portion It is less than 50% of the WPT. The method of claim 19, wherein the step of applying a treatment fluid to the exposed body portion comprises spraying the treatment fluid through the nozzle onto the body portion of the back side of the workpiece. The method of claim 19, wherein the step of applying a treatment fluid to the exposed body portion comprises immersing the exposed body portion within a treatment fluid volume. The method of claim 19, wherein the treatment fluid is selected from the group consisting of free water, hydrogen peroxide, ozone, potassium hydroxide, sodium hydroxide, hydrofluoric acid, nitric acid, sulfuric acid, citric acid, and phosphoric acid. The treatment fluid of the group. The method of claim 19, further comprising the step of rinsing the body portion of the workpiece after the workpiece is thinned. The method of claim 23, wherein the rinsing step comprises applying phosphoric acid to the body portion of the workpiece after the workpiece is thinned. The method of claim 23, further comprising the step of drying the thinned workpiece. The method of claim 19, wherein the treatment fluid is applied to the exposed portion of the body at a first etch rate and then applied to the exposed portion of the body at a second etch rate. The method of claim 26, wherein the first etch rate is greater than the second etch rate. The method of claim 19, further comprising the step of measuring the thickness of the body portion of the workpiece. The method of claim 19, wherein the treatment fluid has a flow rate, a concentration, and a temperature, and the method further comprises the step of monitoring the flow rate of the treatment fluid, the concentration, and at least one of the temperatures. A method of thinning a back side of a semiconductor workpiece, comprising the steps of: placing the semiconductor workpiece on a chuck; attaching a fastener to the chuck to fix the workpiece to the chuck, and the fastener Surrounding a peripheral portion of the back side of the workpiece to expose a body portion of the back side of the workpiece; placing the chuck into a carrier; loading the carrier into a processing chamber; Rotating the collet in the processing chamber; and applying a portion of the exposed body of the processing fluid to the back side of the workpiece as the collet rotates to thin the body portion of the back side of the workpiece The thickness is increased to a thickness and a peripheral edge having a thickness greater than the thickness of the body portion is produced.