Semiconductor apparatus and method for processing a semiconductor workpiece

Abstract

A semiconductor apparatus and method for processing a semiconductor workpiece are provided. A semiconductor apparatus for pre-wetting a semiconductor workpiece includes a process chamber, a workpiece holder disposed within the process chamber to hold the semiconductor workpiece, a pre-wetting fluid tank disposed outside the process chamber and containing a pre-wetting fluid, and a conduit coupled to the pre-wetting fluid tank and extending into the process chamber. The conduit delivers the pre-wetting fluid from the pre-wetting fluid tank via an outlet of the conduit to wet a major surface of the semiconductor workpiece, the major surface including a plurality of recessed portions.

Description

TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to a semiconductor apparatus and method for processing a semiconductor workpiece, and more particularly to a semiconductor apparatus and method for pre-wetting a semiconductor workpiece. BACKGROUND

[0002] In the production of advanced semiconductor integrated circuits (ICs), electroplated copper is currently used because of its lower resistivity and higher current carrying capacity. However, copper electroplating processes can produce defective conductive features. For example, nanobubbles trapped in the electroplated copper layer can limit the quality of the conductive features and reduce the production yield of IC products. Therefore, one of the ongoing efforts to improve the electrical performance of IC devices is to form defect-free conductive features. SUMMARY

[0003] According to some embodiments, a semiconductor apparatus for pre-wetting a semiconductor workpiece includes a process chamber, a workpiece holder disposed within the process chamber to hold the semiconductor workpiece, a pre-wetting fluid tank disposed outside the process chamber and containing a pre-wetting fluid, and a conduit coupled to the pre-wetting fluid tank and extending into the process chamber. The conduit delivers the pre-wetting fluid from the pre-wetting fluid tank via an outlet of the conduit to wet a major surface of the semiconductor workpiece, the major surface including a plurality of recessed portions.

[0004] According to some embodiments, a method of processing a semiconductor workpiece includes at least the following steps. A semiconductor workpiece is pre-wetted. The pre-wetting includes reducing a pressure in a process chamber, the process chamber containing the semiconductor workpiece held by a workpiece holder, flowing a pre-wetting fluid to the semiconductor workpiece to wet a major surface of the semiconductor workpiece, the major surface including a plurality of recessed portions, and increasing the pressure in the process chamber. A wetting rate on the major surface is adjusted by adjusting a fluid pressure of the pre-wetting fluid, and the recessed portions of the semiconductor workpiece are filled with the pre-wetting fluid during the increasing of the pressure. The pre-wetting fluid is removed from the semiconductor workpiece, and a conductive material is plated on the semiconductor workpiece.

[0005] According to some embodiments, a method of processing a semiconductor workpiece includes at least the following steps. A vacuum is applied to a process chamber, the process chamber containing a semiconductor workpiece held by a workpiece holder, a pre-wetting vapor is introduced into the process chamber, and the pre-wetting vapor is condensed on a major surface of the semiconductor workpiece, the major surface including a plurality of recessed portions. BRIEF DESCRIPTION OF DRAWINGS

[0006] Aspects of the disclosure will best be understood by reading the following detailed description in conjunction with the accompanying drawings, of which:

[0007] Figures 1A-1D is a schematic cross-sectional view of various stages of forming conductive features of a semiconductor structure in accordance with some embodiments.

[0008] Figure 2 is a flowchart illustrating a method of pre-wetting a semiconductor structure in accordance with some embodiments.

[0009] Figure 3A is a schematic cross-sectional view of a pre-wetting apparatus including a semiconductor workpiece disposed on a workpiece holder in accordance with some embodiments.

[0010] Figure 3B is a schematic cross-sectional view of a pre-wetting apparatus including a semiconductor workpiece flushed by a pre-wetting fluid in accordance with some embodiments.

[0011] Figures 4A-4B is a schematic plan view of a semiconductor workpiece disposed on a workpiece holder in accordance with some embodiments.

[0012] Figure 5A is a schematic cross-sectional view of a pre-wetting apparatus including a semiconductor workpiece flushed by a pre-wetting fluid in accordance with some embodiments.

[0013] Figure 5B is a schematic cross-sectional view of another variation of the pre-wetting apparatus shown in Figure 5A in accordance with some embodiments.

[0014] Figure 6A is a schematic cross-sectional view of a pre-wetting apparatus including a semiconductor workpiece flushed by a pre-wetting fluid in accordance with some embodiments.

[0015] Figure 6B is a schematic cross-sectional view of another variation of the pre-wetting apparatus shown in Figure 6A in accordance with some embodiments. DETAILED DESCRIPTION

[0016] The following disclosure provides many different embodiments, or examples, for implementing different characteristics of the provided subject matter. The specific examples below are given for simplicity and clarity in understanding the present disclosure. These are not intended to be exhaustive of all possible implementations or examples. For example, in the following description, forming a first feature on or over a second feature can include embodiments in which the first feature is formed in direct contact with the second feature, and can also include embodiments in which additional features can be formed between the first and second features such that the first and second features can not be in direct contact. Additionally, the present disclosure can repeat reference numerals and / or letters in various examples. Such repetitions are for the purpose of simplicity and clarity and do not necessarily involve the same or identical

[0017] Furthermore, spatial or directional terms, such as "beneath", "below", "lower", "above", "upper" and the like, can be used herein for ease of describing one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatial or directional terms are intended to encompass different orientations of the device in use or operation, in addition to the orientations depicted in the figures. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatial or directional descriptions used herein interpreted accordingly.

[0018] Figures 1A-1D is a schematic cross-sectional view of various stages of forming a conductive feature of a semiconductor structure in accordance with some embodiments. Referring to Figure 1A , a base layer 11 of a semiconductor structure 10 is provided with an opening OP, and a seed material layer 121 can be conformally formed on the base layer 11. In some embodiments, the base layer 11 is a semiconductor wafer (e.g., a silicon wafer) or a portion of a semiconductor wafer. The base layer 11 can be or can include a semiconductor substrate, such as a bulk semiconductor, that can or can not be doped. In this case, the subsequently formed conductive feature (e.g., 12 in Figure 1D ) can serve as a through substrate via (TSV) in the semiconductor structure 10. In some embodiments in which the base layer 11 is a dielectric layer formed over a semiconductor substrate, the conductive feature can be formed as part of interconnect circuitry in the semiconductor structure 10.

[0019] The openings OP can be formed by acceptable removal techniques, such as photolithography and etching, drilling, and / or such techniques. The depth of the openings OP can range from sub-microns to about 100 microns, with a width-to-depth ratio (width / depth) ranging from about 1 : 1 to about 1 :20. However, this depth can vary and scale with semiconductor processes. It should be noted that the openings OP are shown as not penetrating through the base layer 11, however in some embodiments, the openings OP can be made to penetrate through the base layer 11 to expose elements located below the base layer 11 as desired. It should be appreciated that the cross-sectional shape of the openings is merely an example, and a dual damascene opening including a via connected with a trench can be formed in the base layer according to some embodiments.

[0020] With continued reference to Figure 1A The openings OP can be lined with a seed material layer 121. The material of the seed material layer 121 can include Cu, Ni, Co, Ru, combinations thereof, and the like. For example, the seed material layer 121 can include the same conductive material (e.g., Cu) as used in a subsequent plating process. In some embodiments, the openings OP are first lined with a barrier liner (not shown) and then the seed material layer 121 is deposited on the barrier liner. The barrier liner can bond the conductive material to the base layer (e.g., a dielectric layer) or can prevent interaction between the conductive material and the base layer (e.g., a silicon substrate). For example, the material of the barrier liner includes Ta, TaN, Ti, TiN, combinations thereof, and the like.

[0021] Referring to Figure 1B A pre-wetting process 20 is performed on the semiconductor structure 10. For example, the seed material layer 121 is treated by the pre-wetting process 20 to enhance wettability. The wettability of the seed material layer can be critical for a subsequent plating process. If the seed material layer is unable to wet the plating fluid, then the plating material cannot be deposited on that area of the seed material layer, resulting in a defect. The pre-wetting process can involve using a fluid to wet the semiconductor structure 10. In some cases, spraying the pre-wetting fluid onto the semiconductor structure 10 results in undesirable bubble generation. These bubbles can be forced into the openings due to pressure differentials during the process. During a subsequent plating process, these bubbles in the openings become blockage points, hindering plating at these points and resulting in associated defect generation. Pre-wetting apparatus and pre-wetting methods that can avoid bubble formation will be set forth in other embodiments later.

[0022] Referring to Figure 1CA conductive material layer 122 is formed over the seed material layer 121. The conductive material layer 122 can be a metallic material including metals or metal alloys, such as copper, silver, gold, tungsten, cobalt, aluminum, or alloys thereof. For example, after a pre-wetting process, electrochemical plating (ECP) is performed to fill the openings OP with the conductive material layer 122. In some embodiments, the semiconductor structure 10 is immersed in an electrolyte bath (not shown). As the semiconductor structure 10 is electrically biased with respect to the electrolyte bath, the conductive material is electrochemically deposited on the semiconductor structure 10. However, the conductive material layer 122 can be formed using electroless plating according to some embodiments.

[0023] Referring to Figure 1D The excess material formed over the major surface 11a of the base layer 11 is removed to form the semiconductor structure 10 having the conductive feature 12 embedded in the base layer 11. In some embodiments, planarization (e.g., chemical mechanical polishing, etching, grinding, combinations thereof, etc.) is performed to remove the excess material. In some embodiments, after planarization, the surface of the conductive material layer 122 and the surface of the seed material layer 121 form a major surface 12a that is substantially planar with the major surface 11a of the base layer 11. In some embodiments, the barrier liner formed between the base layer 11 and the seed material layer 121 is also removed by planarization. After planarization, the remaining portions of the conductive material layer 122 and the seed material layer 121 that are laterally covered by the base layer 11 are collectively considered the conductive feature 12.

[0024] Figure 2 is a flowchart illustrating a method of pre-wetting a semiconductor structure according to some embodiments. It should be understood that although the process 20 is illustrated as a series of steps, the order of the steps should not be construed as limiting. For example, some steps can occur in different orders and / or at the same time with other steps not presented and / or described herein. Additionally, one or more aspects or embodiments described herein can not require performance of all of the steps outlined. Further, one or more of the steps depicted herein can be carried out in one or more separate acts and / or stages.

[0025] Referring to Figure 2 In step 201, a semiconductor workpiece is placed on a workpiece holder in a process chamber. The semiconductor workpiece can be a pre-wetting target (e.g., a semiconductor wafer, a semiconductor die, etc.). In some embodiments, the semiconductor workpiece is a semiconductor wafer having a plurality of semiconductor dies formed thereon. In some embodiments, the semiconductor workpiece is a semiconductor die having a plurality of features formed thereon. Figure 1Bsemiconductor structure 10) shown in FIG. 1. The semiconductor workpiece to be wetted can be provided in wafer form, and the semiconductor wafer can include a plurality of regions bounded with integrated circuits, each region can have one or more semiconductor dies. The semiconductor workpiece is not intended to be limited to any particular type. In some embodiments, forming the seed material layer, pre-wetting, and subsequent plating are performed in separate chambers (or apparatuses), so the semiconductor workpiece can be transferred from a preceding chamber to a following chamber. In some embodiments, the process chamber for pre-wetting the semiconductor workpiece is part of a plating system. The workpiece holder can include any suitable element or can be provided in any form for carrying and restraining the semiconductor wafer. Details of the workpiece holder are described later in connection with Figures 3A-6B Details of the process chamber are described.

[0026] At step 202, the pressure in the process chamber can be reduced. For example, after the semiconductor workpiece is placed, the process chamber is sealed and the pressure within the process chamber is reduced. For example, a vacuum environment is created in the process chamber. In some embodiments, during this step, air within the openings of the semiconductor workpiece is evacuated. In some embodiments, a pump (e.g., a vacuum pump) is employed to evacuate the process chamber from atmospheric pressure to sub-atmospheric pressure (e.g., a low vacuum pressure). The pressure within the process chamber can be controlled to a desired pressure, for example, in a range of about 50 Torr to about 100 Torr, using a pump coupled to the process chamber.

[0027] At step 203, the main surface of the semiconductor workpiece is rinsed using a pre-wetting fluid. For example, the pre-wetting fluid is deionized water. Alternatively, the pre-wetting fluid includes deionized water, acid, and / or such fluids. In some embodiments, the pre-wetting fluid is degassed before it contacts the main surface of the semiconductor workpiece. In some embodiments, when the degassed pre-wetting fluid is applied to the semiconductor workpiece, a sub-atmospheric pressure (e.g., a vacuum condition) is maintained in the process chamber. During this step, the semiconductor workpiece held by the workpiece holder can or can not be rotated. In some embodiments, the semiconductor workpiece is rotated at a slow rate. For example, the rotation speed is between about 50 rpm to about 100 rpm, for example, about 50 rpm. The semiconductor workpiece can be wetted by gently wetting the main surface with the pre-wetting fluid to avoid forming air bubbles. Details of the wetting are described later in connection with Figures 3A-6B Details of the wetting are described.

[0028] At steps 204-205, after the wetting step, the semiconductor workpiece is allowed to sit for a brief period of time, for example, in a range of about 10 seconds to about 1 minute. In some embodiments, step 204 is skipped. Next, the pressure within the process chamber can be increased. For example, the vacuum in the process chamber is released. In some embodiments, the process chamber is vented to atmospheric pressure (e.g., about 760 Torr).

[0029] At steps 206-207, the semiconductor workpiece is allowed to dry to remove the pre-wetting fluid from the major surface. For example, a spin-drying process is performed in which the semiconductor workpiece is spun at a rate in a range from about 200 rpm to about 400 rpm for a duration in a range from about 10 seconds to about 30 seconds. After spin-drying is complete, the semiconductor workpiece can be allowed to sit for a brief period of time. Other suitable drying methods can be employed. Thereafter, the semiconductor workpiece is removed from the process chamber for further processing (e.g., plating as shown in FIG. 20). Figure 1C

[0030] Figure 3A is a schematic cross-sectional view illustrating a pre-wetting apparatus including a semiconductor workpiece disposed on a workpiece holder, and Figure 3B is a schematic cross-sectional view illustrating a pre-wetting apparatus including a semiconductor workpiece being rinsed by a pre-wetting fluid, in accordance with some embodiments. Figures 4A-4B is a schematic plan view illustrating a semiconductor workpiece disposed on a workpiece holder, in accordance with some embodiments. The process 20 described in FIG. 20 can be performed with the pre-wetting apparatus shown herein. Unless otherwise noted, Figure 2 the components referred to in FIG. 20 are essentially identical to the similar components described below. Figure 2

[0031] Referring to FIG. 21, Figure 3A a pre-wetting apparatus 30 is provided, and a semiconductor workpiece W is placed on a workpiece holder 310 within a process chamber 305 of the pre-wetting apparatus 30. The semiconductor workpiece W can be a pre-wetting target (e.g., a semiconductor structure 10 as shown in FIG. 20). A major surface WS1 of the semiconductor workpiece W (e.g., a top surface of a seed material layer 121) can be hydrophilic and have recessed features to be wetted and plated. The workpiece holder 310 can be disposed in a disk form or can include a number of arms for supporting the semiconductor workpiece W. The semiconductor workpiece W is engaged with the workpiece holder 310 using any suitable holding means (e.g., pins, clamps, etc.), where the holding means can support and / or affix the semiconductor workpiece W during processing. In some embodiments, the workpiece holder 310 is coupled to a movement mechanism 320 (e.g., a motor, a controller, a shaft, a combination of these structures, and / or such mechanisms). The movement mechanism 320 is configured to drive the workpiece holder 310 to perform movements (e.g., translations, tilts, rotations, and / or such movements) on the semiconductor workpiece W. In some embodiments, a bottom of the process chamber 305 is used as a sump to collect overflowed pre-wetting fluid. For example, the bottom of the process chamber 305 is provided with a drain port 305D to drain the overflowed pre-wetting fluid. Figure 1B

[0032] ​​​In some embodiments, the pre-wetting fluid tank 330 is adapted to deliver the pre-wetting fluid to the semiconductor workpiece W through the at least one conduit 322. The pre-wetting fluid tank 330 can be disposed outside the process chamber. But the pre-wetting fluid tank 330 can have other configurations. In some embodiments, a flow controller 335 is disposed upstream of the outlet of the conduit. In some embodiments, the water level in the pre-wetting fluid tank 330 is lower than the workpiece holder 310, and the pre-wetting fluid tank 330 is equipped with a flow controller 335, such as a pump, for driving the pre-wetting fluid in the pre-wetting fluid tank 330 to flow to the semiconductor workpiece W. Alternatively, the pre-wetting fluid is delivered by suction force generated by the pressure difference between the pre-wetting fluid tank 330 and the process chamber 305.

[0033] In some embodiments, the conduit 322 is coupled to the pre-wetting fluid tank 330 and assembled on the workpiece holder 310. Although two conduits 322 are shown, no limitation is intended to the number of conduits. For example, some portions of the conduit 322 are embedded in the workpiece holder 310 to form a channel 322a within the workpiece holder 310. In some embodiments, the channel 322a is a hollow passage in the workpiece holder 310. The flow path of the pre-wetting fluid through the channel 322a can be located below the semiconductor workpiece W and along the sidewall WS2 of the semiconductor workpiece W. In some embodiments, the channel 322a is in fluid communication with the pre-wetting fluid tank 330, and the pre-wetting fluid can flow to the semiconductor workpiece W through the outlet of the channel 322a, which is defined by the inner sidewall 310a and the outer sidewall 310b of the workpiece holder 310. The inner sidewall 310a and the outer sidewall 310b of the workpiece holder 310 can be substantially parallel to the sidewall WS2 of the semiconductor workpiece W. The outer sidewall 310b can be higher than the inner sidewall 310a with reference to the main surface WS1. In some embodiments, the shortest distance H1 between the top of the outer sidewall 310b and the reference plane where the main surface WS1 is located is greater than the shortest distance H2 between the top of the inner sidewall 310a and the reference plane where the main surface WS1 is located. For example, the inner sidewall 310a and the outer sidewall 310b of the workpiece holder 310 can act as overflow weirs, and due to the height difference, the pre-wetting fluid delivered through the channel 322a can overflow out of the inner sidewall 310a and then overflow out of the outer sidewall 310b.

[0034] With continued reference to Figure 3A and with reference to Figure 4A and Figure 4B The outlet of the channel 322a can be disposed in any suitable manner. For example, when viewed from above (e.g., from the direction of the main surface WS1), the outlet of the channel 322a can be located at the top of the outer sidewall 310b. Alternatively, the outlet of the channel 322a can be located at the top of the inner sidewall 310a. In some embodiments, the outlet of the channel 322a is located at the top of the inner sidewall 310a and the outer sidewall 310b. In some embodiments, the outlet of the channel 322a is located at the top of the inner sidewall 310a and the outer sidewall 310b, and the outlet of the channel 322a is located at the top of the inner sidewall 310a and the outer sidewall 310b. Figure 4AThe outlets of channel 322a are distributed around the periphery of the semiconductor workpiece W. Pre-wetting fluid can be discharged from these outlet ports and flow to the main surface WS1 of the semiconductor workpiece W, as indicated by arrow A1. In this way, the main surface WS1 of the semiconductor workpiece W can be wetted from the edge to the center. The outlets can have any top-view shape, such as square, rectangular, circular, elliptical, polygonal, etc. Note that... Figure 4A The four outlets shown are merely examples; pre-lubricating fluid can be discharged through a single outlet or multiple outlets, and the number of outlets is not limited in this disclosure. In some embodiments, when viewed from above (e.g., Figure 4B The outlet of channel 322a is a trench surrounding the periphery of the semiconductor workpiece W. The outlet of channel 322a can be a continuous annular trench along the periphery of the semiconductor workpiece W or it can be a discontinuous trench. Other suitable configurations of the outlet may exist. Pre-wetting fluid can overflow from the trench to the semiconductor workpiece W, and then flow from the edge to the center, as indicated by arrow A1.

[0035] refer to Figure 3B The semiconductor workpiece W is rinsed with pre-wetting fluid DW. Figure 3B The situation shown can correspond to Figure 2 Step 203 as described above. In some embodiments, during the wetting step, the semiconductor workpiece W is rotated about an axis AX that passes through the center of the semiconductor workpiece W and is perpendicular to the main surface WS1. For example, the semiconductor workpiece W is driven to rotate clockwise (or counterclockwise) by a moving mechanism 320. Alternatively, the semiconductor workpiece W is not rotated during the wetting step. Dashed arrows indicate whether rotation may or may not be performed during wetting.

[0036] In some embodiments, the pre-wetting fluid DW is degassed prior to delivery to the semiconductor workpiece W. For example, a degasser (not shown) is configured to remove (or reduce) dissolved gases from the pre-wetting fluid DW before the pre-wetting fluid DW enters the conduit 322. In some embodiments, the water level in the pre-wetting fluid tank 330 is lower than the workpiece holder 310, and the pre-wetting fluid DW in the pre-wetting fluid tank 330 can be delivered upward through the conduit 322, as indicated by arrow A2. The pre-wetting fluid DW can then flow through the channel 322a in the workpiece holder 310, as indicated by arrow A3. Next, the pre-wetting fluid DW can overflow the inner sidewall 310a of the workpiece holder 310 to contact the major surface WS1 of the semiconductor workpiece W, as indicated by arrow Al. The flow of water of the pre-wetting fluid DW can gently and gently wet the major surface WS1 of the semiconductor workpiece W without generating air bubbles. For example, the wetting rate on the major surface WS1 is adjusted by adjusting the fluid pressure of the pre-wetting fluid DW. To avoid impinging the major surface with a jet of fluid having a high fluid pressure, the flow of water of the pre-wetting fluid DW in contact with the major surface WS1 of the semiconductor workpiece W can be adjusted to have a relatively low fluid pressure. Note that any suitable flow controller (not shown; e.g., a valve, a controller, a sensor, etc.) can be employed to achieve the pressure requirement and the flow requirement. For example, the fluid pressure is controlled in a range from about 10 pounds per square inch (psi) to about 100 psi.

[0037] The pre-wetting fluid DW can continuously flow out through the channel 322a to wet the semiconductor workpiece W. Excess pre-wetting fluid DW can overflow the outer sidewall 310b of the workpiece holder 310 and flow downward to the bottom of the process chamber 305, as indicated by arrow A4. In some embodiments, due to the pressure difference (e.g., step 205 described in Figure 2 , the pressure in the process chamber is increased), the pre-wetting fluid DW can fill the recessed features (or openings) on the major surface WS1 of the semiconductor workpiece W. In some embodiments, during step 206 described in Figure 2 , the pre-wetting fluid DW is removed from the major surface WS1 of the semiconductor workpiece W, and can be collected at the bottom of the process chamber 305, and these pre-wetting fluid DW at the bottom of the process chamber 305 can be drained through the drain port 305D.

[0038] Figure 5A is a schematic cross-sectional view illustrating a pre-wetting apparatus according to some embodiments, the pre-wetting apparatus including a semiconductor workpiece being rinsed by a pre-wetting fluid. Figure 5A The situation shown in Figure 2 corresponds to step 203 described in Figure 5A The pre-wetting apparatus 40A shown is similar to the pre-wetting apparatus 30 shown in Figure 3A , and therefore similar reference numbers are used to identify similar elements.

[0039] Referring to Figure 5A The semiconductor workpiece W is wetted by flowing pre-wetting fluid DW from the pre-wetting fluid tank 430 to the semiconductor workpiece W. During the wetting step, the semiconductor workpiece W can or can not be driven to rotate by the movement mechanism 320. In some embodiments, the pre-wetting fluid tank 430 disposed outside the process chamber 305 is coupled to the conduit 422, where the conduit 422 extending into the process chamber 305 is positioned above the semiconductor workpiece W to deliver the pre-wetting fluid DW downward to the major surface WS1 of the semiconductor workpiece W. In some embodiments, the lateral dimension D1 (e.g., diameter) of the outlet 422o is less than about 3 mm, such as in a range from about 1 mm to about 3 mm. It is noted that the lateral dimension D1 can be adjusted according to predetermined flow rates and process requirements.

[0040] In some embodiments, the conduit 422 is movable within the process chamber 305 to be positioned at any desired location. The conduit 422 can be provided as or be part of a priming arm that is driven by a controller (not shown) to perform movement (e.g., swing, lower, raise, etc.). In some embodiments, the outlet 422o of the conduit 422 is positioned at a vertical distance WH1 above the center of the major surface WS1 of the semiconductor workpiece W. Alternatively, the outlet 422o of the conduit 422 is positioned above an edge or other location of the major surface WS1 of the semiconductor workpiece W.

[0041] In some embodiments, the pre-wetting fluid tank 430 is equipped with a flow controller 435, and the pre-wetting fluid DW in the pre-wetting fluid tank 430 can be fed into the conduit 422 through the flow controller 435. The flow controller 435 can include at least one pump (e.g., a syringe pump, a pressure pump, etc.), a valve, a motor, a pipe, etc. Other suitable devices configured to perform pressure control and flow rate control can be utilized. By adjusting the flow rate and pressure of the pre-wetting fluid DW delivered to the semiconductor workpiece W, the semiconductor workpiece W can be gently rinsed. For example, the fluid pressure is controlled in a range from about 5 psi to about 50 psi.

[0042] In some embodiments, the pre-wetting fluid DW is degassed and delivered through the conduit 422. For example, there are no air bubbles within the conduit 422 during delivery of the pre-wetting fluid DW using any suitable technique. In some embodiments, the outlet 422o of the conduit 422 is located above the semiconductor workpiece W and at a position close to the major surface WS1 of the semiconductor workpiece W, and the pre-wetting fluid DW flows out through the outlet 422o to contact the major surface WS1 of the semiconductor workpiece W, as indicated by the arrow A5. For example, the vertical distance WH1 between the outlet 422o of the conduit 422 and the major surface WS1 of the semiconductor workpiece W is in the range from about 1 mm to about 3 mm. The vertical distance WH1 can be adjusted before, during, and after delivery of the pre-wetting fluid DW to the semiconductor workpiece W.

[0043] In some embodiments, as the pre-wetting fluid DW continuously flows to the semiconductor workpiece W, the pre-wetting fluid DW accumulates on the major surface WS1 of the semiconductor workpiece W, and the position of the outlet 422o is kept below the height (water level) of the pre-wetting fluid DW with reference to the major surface WS1. For example, the outlet 422o of the conduit 422 is submerged under the pre-wetting fluid DW above the major surface WS1. In some embodiments, the vertical distance WH1 is less than a vertical distance WH2 between a fluid surface of the pre-wetting fluid DW surrounding the conduit 422 and the major surface WS1 of the semiconductor workpiece W. In some embodiments, as the pre-wetting fluid DW is continuously delivered to the semiconductor workpiece W, the pre-wetting fluid DW gradually and slowly spreads to the edge in the radial direction, as indicated by the dotted arrow A6. Note that the flow path of the pre-wetting fluid DW on the semiconductor workpiece W is represented by dotted lines. For example, the flow of the pre-wetting fluid DW above the major surface WS1 of the semiconductor workpiece W is in a “creeping” flow regime to prevent fluid jet from impinging the major surface WS1. The wetting rate on the major surface WS1 can be adjusted by adjusting the fluid pressure. The creeping flow regime can be achieved by, for example, optimizing the size of the outlet 422o and the length of the conduit 422, adjusting the fluid pressure and velocity by the flow controller 435, etc. It should be noted that the term “creeping flow” as used herein can refer to a flow with low fluid pressure and velocity (or flow rate).

[0044] The spreading rate of the pre-wetting fluid DW over the semiconductor workpiece W can be adjusted to avoid turbulence and / or to form bubbles. For example, the use of the flow controller 435 facilitates control of the fluid pressure and flow rate of the pre-wetting fluid DW fed into the conduit 422. The lateral dimension Dl of the outlet 422o can be designed to allow a small amount of the pre-wetting fluid DW to flow out through the outlet 422o. In this way, the pre-wetting fluid DW can gently wet the major surface WS1 of the semiconductor workpiece W to prevent fluid jets from being sprayed onto the major surface WS1. In some embodiments, keeping the outlet 422o submerged in the pre-wetting fluid DW while wetting the semiconductor workpiece W can prevent bubbles from being introduced into the pre-wetting fluid DW over the semiconductor workpiece W. As the pre-wetting fluid DW continues to wet the major surface WS1 of the semiconductor workpiece W, excess pre-wetting fluid DW over the semiconductor workpiece W can overflow the top surface of the workpiece holder 410 (as shown by the arrow A4), and then the overflowed pre-wetting fluid DW can be drained through the drain port 305D.

[0045] Figure 5B is a schematic cross-sectional view illustrating a pre-wetting apparatus according to some embodiments. Figure 5A is another variation of the pre-wetting apparatus shown in Figure 5B is a schematic cross-sectional view illustrating a pre-wetting apparatus according to some embodiments. Figure 5A is another variation of the pre-wetting apparatus shown in Figure 5A , the pre-wetting apparatus 40B is configured with multiple conduits 422a to deliver the pre-wetting fluid DW. Although two conduits are shown, it is understood that more than two conduits can be configured. In some embodiments, the conduits 422a are positioned above the semiconductor workpiece W to deliver the pre-wetting fluid DW from the pre-wetting fluid tank 430 toward the semiconductor workpiece W, as shown by the arrows A5. The conduits 422a can be distributed along the perimeter of the semiconductor workpiece W, and the pre-wetting fluid DW flowing to the semiconductor workpiece W can spread from the edges to the center of the major surface WS1 of the semiconductor workpiece W, as shown by the dashed arrows A61. In some embodiments, one of the conduits is positioned at the center of the semiconductor workpiece W and another of the conduits is positioned at the edge of the semiconductor workpiece W. Further, the conduits can have other configurations.

[0046] Figure 6A is a schematic cross-sectional view illustrating a pre-wetting apparatus according to some embodiments, the pre-wetting apparatus including a semiconductor workpiece being rinsed by a pre-wetting fluid. Figure 6A The pre-wetting apparatus 50A shown is similar to the pre-wetting apparatus 30 described in Figure 3A and Figure 3B , similar elements are labeled with similar reference numbers, and details of similar elements are not repeated for brevity. Figure 6A The situation shown can correspond to Figure 2The step 203 is described in the middle. The dashed arrow represents that rotation can or can not be performed during wetting.

[0047] Referring to Figure 6A The conduit 522 is coupled to the pre-wetting fluid tank 530 and extends into the process chamber 505A to deliver the pre-wetting fluid from the pre-wetting fluid tank 530 into the process chamber 505A in vapor form. In some embodiments, the pre-wetting fluid is a condensable fluid vapor that can or can not be degassed before being introduced into the process chamber 505A. As used herein, the pre-wetting fluid in vapor form is referred to as pre-wetting vapor DV. In some embodiments, the pre-wetting vapor DV is formed by vaporizing deionized water. The pre-wetting vapor DV can include other substances depending on process requirements. The pre-wetting fluid tank 530 can contain a high moisture content (e.g., about 100% relative humidity). For example, the pre-wetting fluid tank 530 is equipped with a heater 531 (e.g., a heater, a hot plate, a vapor generator, and / or the like) configured to heat and vaporize the pre-wetting fluid. In some embodiments, the temperature in the pre-wetting fluid tank 530 is maintained above about 90 degrees Celsius. However, the temperature in the pre-wetting fluid tank can vary depending on the content and pressure of the pre-wetting fluid.

[0048] In some embodiments, to ensure that the pre-wetting vapor DV flows into the process chamber 505A without condensing within the conduit, the conduit 522 is maintained in a heated condition, e.g., using an example heater 531’. The heater 531’ that is equipped with the conduit 522 can be the same as or similar to the heater 531 that is equipped with the pre-wetting fluid tank 530. It should be understood that the number and configuration of the conduits and heaters herein are not limited. For example, a portion of the conduit 522 that extends into the process chamber 505A is at an upper portion 505t of the process chamber 505A and is positioned above the semiconductor workpiece W, and the portion of the conduit 522 can include a plurality of holes (or outlets) 522h distributed on the sidewall of the conduit 522. The pre-wetting vapor DV can enter the process chamber 505A through the holes 522h, as shown by the dashed arrows A7. In some embodiments, the portion of the conduit 522 is disposed vertically (or obliquely) with respect to the major surface WS1 of the semiconductor workpiece W to avoid fluid droplets from falling directly onto the major surface WS1 of the semiconductor workpiece W. It should be understood that the number, size, and configuration of the holes are shown for illustrative purposes only and can vary depending on process requirements.

[0049] In some embodiments, process chamber 505A includes an inclined surface 5051 connected to the chamber sidewalls and top plate. The inclined surface 5051 may be configured to prevent pre-wetting vapor DV from condensing on the top of the process chamber, where condensed pre-wetting vapor DV may reside above the semiconductor workpiece W and potentially drip onto it. For example, the inclined surface 5051 guides pre-wetting vapor DV condensed on the top plate of process chamber 505A to an overflow container (e.g., the bottom of the process chamber) and then discharges it through a drain port 305D. Note that the angle of inclination of the inclined surface 5051 relative to the sidewalls of process chamber 505A may be determined according to the chamber design and is not limited herein. The inclined surface 5051 may be replaced by any suitable baffle or other configuration.

[0050] Continue to refer to Figure 6A The workpiece holder 410 of the pre-wetting apparatus 50A may be equipped with a temperature controller 515 (e.g., a thermoelectric cooler, heat exchanger, cooling plate, and / or such devices). In some embodiments, the temperature controller 515 is configured to reduce the temperature of the semiconductor workpiece W disposed on the workpiece holder 410. For example, during the wetting step, the temperature controller 515 is used to reduce the temperature of the semiconductor workpiece W to below the condensation temperature (e.g., dew point temperature) of the pre-wetting vapor DV. This allows the pre-wetting vapor DV introduced into the process chamber 505A to condense, forming a pre-wetting fluid DW on the main surface WS1 of the semiconductor workpiece W. The condensation temperature may vary depending on parameters such as the amount of pre-wetting fluid, the operating pressure in the process chamber, etc.

[0051] In some embodiments, to facilitate the condensation process on the main surface WS1 of the semiconductor workpiece W, the operating temperature in the process chamber 505A is set above the condensation temperature (e.g., dew point temperature) of the pre-wetting vapor DV to prevent condensation of the pre-wetting vapor DV on the chamber sidewalls and / or top plate. As the pre-wetting vapor DV is continuously delivered through the orifice 522h of the conduit 522, the condensed pre-wetting vapor DV on the main surface WS1 of the semiconductor workpiece W gradually forms a flow of water that wets the main surface WS1. The condensation process performed on the semiconductor workpiece W allows for the slow formation of the pre-wetting fluid DW on the main surface WS1 without the formation of bubbles. In some embodiments, during the wetting step and when the pressure in the process chamber 505A changes (e.g., step 205), the recessed portion of the main surface WS1 of the semiconductor workpiece W is filled with the condensed pre-wetting fluid DW. Excess pre-wetting fluid DW on the semiconductor workpiece W can overflow from the top surface of the workpiece holder 410 (as shown by arrow A4), and the overflowed pre-wetting fluid can then be discharged through the drain port 305D.

[0052] Figure 6B This is an explanation based on some embodiments. Figure 6AA schematic cross-sectional view of another variation of the pre-lubrication device shown. Similar reference numerals are used to identify similar elements, and for the sake of brevity, details of similar elements are not repeated. Reference Figure 6B And refer to Figure 6A Pre-lubrication equipment 50B and Figure 6A The difference between the pre-wetting devices 50A is that the process chamber 505A includes a dome-shaped top plate 5052. For example, the dome-shaped top plate 5052 may engage with the chamber sidewalls to form a vacuum seal, if necessary. During the wetting step, condensed pre-wetting fluid DW (if any) formed on the top of the process chamber 505B may be directed to an overflow container (e.g., the bottom of the process chamber) and then discharged through a drain port 305D. By configuring the dome-shaped top plate 5052, pre-wetting vapor DV condensed on the top of the process chamber is prevented from residing above the semiconductor workpiece W and potentially dripping onto it.

[0053] According to some embodiments, a semiconductor apparatus for pre-wetting a semiconductor workpiece includes: a process chamber; a workpiece holder disposed within the process chamber to hold the semiconductor workpiece; a pre-wetting fluid tank disposed outside the process chamber and containing pre-wetting fluid; and a conduit coupled to the pre-wetting fluid tank and extending into the process chamber. The conduit delivers the pre-wetting fluid from the pre-wetting fluid tank via an outlet of the conduit to wet a main surface of the semiconductor workpiece, the main surface including a plurality of recessed portions.

[0054] In some embodiments, a portion of the conduit is located within the workpiece holder, and the outlet of the conduit is positioned adjacent to the edge of the semiconductor workpiece. In some embodiments, the workpiece holder includes an inner sidewall that contacts the edge of the semiconductor workpiece, and the pre-wetting fluid flowing through the conduit overflows from the inner sidewall of the workpiece holder to the main surface of the semiconductor workpiece. In some embodiments, the workpiece holder includes an outer sidewall that is higher than the inner sidewall relative to the main surface of the semiconductor workpiece, and excess pre-wetting fluid overflows from the outer sidewall of the workpiece holder. In some embodiments, the outlet of the conduit is positioned at a vertical distance above the main surface of the semiconductor workpiece, and the outlet of the conduit is immersed in the pre-wetting fluid above the semiconductor workpiece as the pre-wetting fluid continues to flow to the semiconductor workpiece. In some embodiments, the semiconductor device further includes a flow controller coupled to the pre-wetting fluid reservoir to regulate the fluid pressure of the pre-wetting fluid flowing to the semiconductor workpiece to a range of approximately 5 psi and approximately 50 psi. In some embodiments, the semiconductor device further includes a first temperature controller coupled to the pre-wetting fluid tank to cause the pre-wetting fluid to evaporate. In some embodiments, the conduit is disposed at the upper portion of the process chamber, the outlet of the conduit including a plurality of holes distributed on the sidewall of the conduit, and the pre-wetting fluid in vapor form enters the process chamber through the holes. In some embodiments, the conduit is coupled to the first temperature controller to maintain a temperature for delivering the pre-wetting fluid in vapor form. In some embodiments, the semiconductor device further includes a second temperature controller coupled to the workpiece holder to reduce the temperature of the semiconductor workpiece to below the dew point temperature of the pre-wetting fluid.

[0055] According to some embodiments, a method for processing a semiconductor workpiece includes at least the following steps: Pre-wetting the semiconductor workpiece. The pre-wetting includes: reducing the pressure in a process chamber containing the semiconductor workpiece held by a workpiece holder; flowing a pre-wetting fluid to the semiconductor workpiece to wet a main surface of the semiconductor workpiece, the main surface including a plurality of recessed portions; and increasing the pressure in the process chamber. The wetting rate on the main surface is adjusted by regulating the fluid pressure of the pre-wetting fluid, and the recessed portions of the semiconductor workpiece are filled with the pre-wetting fluid during the pressure increase. The pre-wetting fluid is removed from the semiconductor workpiece, and a conductive material is deposited on the semiconductor workpiece.

[0056] In some embodiments, flowing the pre-wetting fluid to the semiconductor workpiece includes flowing the pre-wetting fluid within the workpiece holder and overflowing the pre-wetting fluid from the inner sidewall of the workpiece holder to the main surface of the semiconductor workpiece. In some embodiments, the fluid pressure of the pre-wetting fluid flowing to the semiconductor workpiece is adjusted to a range of 10 psi to about 100 psi. In some embodiments, the pre-wetting fluid is delivered through a conduit including an outlet positioned above the main surface of the semiconductor workpiece, and flowing the pre-wetting fluid to the semiconductor workpiece includes accumulating the pre-wetting fluid on the main surface of the semiconductor workpiece and maintaining the outlet of the conduit submerged in the pre-wetting fluid on the main surface of the semiconductor workpiece. In some embodiments, flowing the pre-wetting fluid to the semiconductor workpiece includes maintaining the pre-wetting fluid flowing in the conduit free of air bubbles. According to some embodiments, a method of processing a semiconductor workpiece includes at least the following steps. A vacuum is applied to a process chamber containing a semiconductor workpiece held by a workpiece holder, pre-wetting vapor is introduced into the process chamber, and the pre-wetting vapor is condensed on the main surface of the semiconductor workpiece, the main surface including a plurality of recessed portions.

[0057] In some embodiments, the pre-wetting vapor is delivered via a conduit extending above the semiconductor workpiece within the process chamber and including a plurality of orifices, and introducing the pre-wetting vapor into the process chamber includes maintaining the conduit at a temperature that allows the pre-wetting vapor to flow within the conduit and out through the orifices into the process chamber. In some embodiments, the workpiece holder is equipped with a temperature controller, and condensing the pre-wetting vapor on the semiconductor workpiece includes cooling the semiconductor workpiece using the temperature controller. In some embodiments, the method further includes releasing the vacuum, wherein the recessed portion of the semiconductor workpiece is filled with pre-wetting fluid formed by condensing the pre-wetting vapor, removing the pre-wetting fluid from the semiconductor workpiece, and depositing a conductive material onto the semiconductor workpiece.

[0058] The foregoing has outlined features of several embodiments to enable those skilled in the art to better understand various aspects of this disclosure. Those skilled in the art will understand that they can readily use this disclosure as a basis for designing or modifying other processes and structures to achieve the same purposes and / or attain the same advantages as the embodiments described herein. Those skilled in the art should also recognize that such equivalent constructions do not depart from the spirit and scope of this disclosure, and that various changes, substitutions, and modifications can be made herein without departing from the spirit and scope of this disclosure.

[0059] [Explanation of Symbols]

[0060] 10: Semiconductor Structure

[0061] 11: Basal layer

[0062] 11a, 12a, WS1: Main surfaces

[0063] 12: Electrical conductivity characteristics

[0064] 20: Pre-lubrication process / process

[0065] 30, 40A, 40B, 50A, 50B: Pre-lubrication equipment

[0066] 121: Seed Material Layer

[0067] 122: Conductive material layer

[0068] 201, 202, 203, 204, 205, 206, 207: Steps

[0069] 305, 505A, 505B: Process chambers

[0070] 305D: Drainage port

[0071] 310, 410: Workpiece holder

[0072] 310a: Inner wall

[0073] 310b: Lateral wall

[0074] 320: Mobile Agency

[0075] 322, 422, 422a, 522: Catheters

[0076] 322a: Channel

[0077] 330, 430, 530: Pre-wetting fluid tank

[0078] 335, 435: Flow controller

[0079] 422o: Export

[0080] 505t: Upper part

[0081] 515: Temperature Controller

[0082] 522h: Hole

[0083] 531, 531': Heater

[0084] 5051: Inclined surface

[0085] 5052: Dome-shaped top plate

[0086] A1, A2, A3, A4, A5, A6, A61, A7: Arrows

[0087] AX: Axis

[0088] D1: Lateral dimension

[0089] DV: Pre-wetting steam

[0090] DW: Pre-wetting fluid

[0091] H1, H2: Shortest distance

[0092] OP: Opening

[0093] W: Semiconductor workpiece

[0094] WH1, WH2: Vertical distance

[0095] WS2: Sidewall.

Claims

1. A semiconductor apparatus for pre-lubricating semiconductor workpieces, comprising: Process chambers; A workpiece holder is disposed within the process chamber to hold the semiconductor workpiece, the workpiece holder including an inner sidewall that contacts the edge of the semiconductor workpiece; A pre-wetting fluid tank is located outside the process chamber and contains pre-wetting fluid; as well as A conduit, coupled to the pre-wetting fluid reservoir and extending into the process chamber, delivers the pre-wetting fluid from the pre-wetting fluid reservoir via an outlet of the conduit to wet the main surface of the semiconductor workpiece, the main surface including a plurality of recessed portions, wherein a portion of the conduit is located in the workpiece holder, the outlet of the conduit is located next to the edge of the semiconductor workpiece, and the pre-wetting fluid flowing through the conduit overflows from the inner sidewall of the workpiece holder to the main surface of the semiconductor workpiece.

2. The semiconductor device of claim 1, wherein the shortest distance between the top of the outer sidewall of the workpiece holder and the reference plane on which the main surface of the semiconductor workpiece is located is greater than the shortest distance between the top of the inner sidewall of the workpiece holder and the reference plane on which the main surface of the semiconductor workpiece is located.

3. The semiconductor device according to claim 1, wherein the inner sidewall and the outer sidewall of the workpiece holder can be used as an overflow weir.

4. The semiconductor device of claim 1, wherein the workpiece holder includes an outer wall that is higher than the inner sidewall based on the main surface of the semiconductor workpiece, and excess portion of the pre-wetting fluid overflows from the outer wall of the workpiece holder.

5. The semiconductor device of claim 1, wherein the pre-wetting fluid flows through a flow path of the conduit, the flow path being located below the semiconductor workpiece and along the sidewall of the semiconductor workpiece.

6. The semiconductor device according to claim 1, further comprising: A drain port is located at the bottom of the process chamber to drain any overflow of the pre-wetting fluid.

7. The semiconductor device according to claim 1, wherein the outer sidewall of the workpiece holder and the inner sidewall of the workpiece holder are parallel to the sidewall of the semiconductor workpiece.

8. The semiconductor device according to claim 1, further comprising: A moving mechanism is coupled to the workpiece holder and configured to drive the workpiece holder to move the semiconductor workpiece.

9. The semiconductor device of claim 1, wherein the outlet of the conduit is distributed around the semiconductor workpiece.

10. The semiconductor device of claim 9, wherein the outlet of the conduit is a trench surrounding the periphery of the semiconductor workpiece.

11. The semiconductor device according to claim 1, further comprising: A flow controller is located upstream of the outlet of the conduit.

12. A method for processing a semiconductor workpiece, comprising: Pre-lubrication of semiconductor workpieces includes: Reduce the pressure in the process chamber, which contains the semiconductor workpiece held by the workpiece holder; A pre-wetting fluid is flowed to the semiconductor workpiece to wet its main surface, the main surface including a plurality of recessed portions, wherein the wetting rate on the main surface is adjusted by regulating the fluid pressure of the pre-wetting fluid, and the flow of the pre-wetting fluid to the semiconductor workpiece includes: The pre-wetting fluid flows within the workpiece holder; and The pre-wetting fluid overflows from the inner wall of the workpiece holder to the main surface of the semiconductor workpiece; and Increase the pressure in the process chamber, wherein the recessed portion of the semiconductor workpiece is filled with the pre-wetting fluid; Remove the pre-wetting fluid from the semiconductor workpiece; and A conductive material is deposited on the semiconductor workpiece.

13. The method for processing a semiconductor workpiece according to claim 12, wherein flowing the pre-wetting fluid to the semiconductor workpiece comprises: The pre-wetting fluid is delivered to the semiconductor workpiece via a conduit, wherein the conduit is embedded in the workpiece holder to allow the pre-wetting fluid to flow within the workpiece holder.

14. The method of processing a semiconductor workpiece according to claim 12, wherein the fluid pressure of the pre-wetting fluid flowing to the semiconductor workpiece is adjusted to a range of 10 psi to about 100 psi.

15. The method for processing a semiconductor workpiece according to claim 13, wherein the pre-wetting fluid flows to the semiconductor workpiece through the outlet of the conduit, the outlet of the conduit being defined by the inner and outer sidewalls of the workpiece holder.

16. The method of processing a semiconductor workpiece according to claim 13, wherein flowing the pre-wetting fluid to the semiconductor workpiece comprises: The pre-wetting fluid flowing in the conduit is kept free of air bubbles.

17. A method for processing a semiconductor workpiece, comprising: Pre-wetting fluid is delivered from a pre-wetting fluid tank via a conduit outlet to wet the main surface of the semiconductor workpiece, wherein the semiconductor workpiece is held in place by a workpiece holder, a portion of the conduit is embedded in the workpiece holder, the outlet of the conduit is located next to the edge of the semiconductor workpiece, and the pre-wetting fluid flowing through the conduit overflows from the inner wall of the workpiece holder to the main surface of the semiconductor workpiece. Remove the pre-wetting fluid from the semiconductor workpiece; as well as A conductive material is deposited on the semiconductor workpiece.

18. The method for processing a semiconductor workpiece according to claim 17, further comprising: The dissolved gas in the pre-wetting fluid is reduced before it enters the conduit.

19. The method for processing a semiconductor workpiece according to claim 17, further comprising: The wetting rate on the main surface of the semiconductor workpiece is adjusted by regulating the fluid pressure of the pre-wetting fluid.

20. The method for processing a semiconductor workpiece according to claim 17, further comprising: Excess pre-wetting fluid overflows from the outer wall of the workpiece holder and flows to the bottom of the process chamber, wherein the workpiece holder is disposed within the process chamber.

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