Contamination control in semiconductor thermal compression bonding and related systems and methods

Abstract

The present application relates to contaminant control in semiconductor thermocompression bonding and related systems and methods. Systems and methods for controlling contamination during thermocompression bonding are provided herein. A tool generally includes a bonding head having a first channel, wherein the first channel extends in a lateral direction from a first port along a second side toward the periphery of the bonding head. In several instances, the bonding head includes a second channel, the second channel fluid is coupled to a second port and extends in a lateral direction along a recessed surface of the bonding head, wherein the second channel at least partially surrounds the first channel. In other instances, the tool includes a vacuum manifold having a vacuum opening positioned laterally outward from the bonding head. A first flow unit is coupled to the first channel and is configured to extract air. A second flow unit is coupled to the second port or the vacuum manifold to extract fluid and prevent degassed bonding material from entering the first channel, being deposited on the bonding head and / or contaminating adjacent semiconductor components.

Description

Technical Field

[0001] The present disclosure relates generally to bonded semiconductor devices and, in several embodiments, more particularly to systems and methods for controlling contamination from outgassing of bonding materials during thermocompression bonding of semiconductor dies. Background Art

[0002] Microelectronic devices such as memory devices, microprocessors, and light emitting diodes typically include one or more semiconductor dies mounted on a substrate and encapsulated in a protective layer. The semiconductor die includes functional features such as a memory cell, a processor circuit, an interconnect circuit, etc. Semiconductor die manufacturers face increasing pressure to reduce the volume occupied by the semiconductor die while increasing the capacity and / or speed of the resulting package assembly. In order to meet these requirements, semiconductor die manufacturers typically stack multiple semiconductor dies vertically on top of each other to increase the capacity or performance of the microelectronic device within a limited volume on a circuit board or other component on which the semiconductor die is mounted. The stack can be bonded together using a bonding material. For such vertically stacked semiconductor dies, through silicon vias (TSVs) are often used. These TSVs on adjacent semiconductor dies are typically electrically connected to each other using direct physical coupling, with the bonding pads of one die directly bonded to the bonding pads of another die.

[0003] In a conventional semiconductor thermal compression bonding (TCB) process, a chip mounting device picks up a semiconductor device via a bonding head by vacuuming. The device then transfers the semiconductor device to a bonding area where the semiconductor device is bonded to a substrate or another semiconductor device. The bonding process is usually performed at high temperatures to ensure that the bonding material (e.g., non-conductive film (NCF), non-conductive paste (NCP), etc.) has an appropriate viscosity and reliably forms interconnections; however, the bonding material evaporates at higher temperatures. In conventional processes, if a temperature level is reached that causes the bonding material to evaporate, the steam will enter and condense in the vacuum line of the bonding head, causing blockage and reducing the strength of the vacuum over time. Further, since there is often a gap between the bonding head and the interface semiconductor die surface (e.g., due to defects and / or warping in the topography of the die surface, or under-bump metal), the steam may travel laterally and deposit contaminants on an area of ​​the bonding tip that is larger than the die surface area, or deposit contaminants on adjacent semiconductor die stacks and other components of the device, resulting in contamination. This contamination of the bonding head can cause the bonding head to stick to the semiconductor die during subsequent bonding operations. To reduce this form of contamination in conventional bonding operations, film assisted bonding (FAB) tapes are often used. Summary of the invention

[0004] In one aspect, the present application provides a semiconductor processing tool, comprising: a bonding head having: a first port extending from a first side of the bonding head toward a second side; a first channel, which is fluidically coupled to the first port and extends in a lateral direction from the first port along the second side toward the periphery of the bonding head, the first channel forming a slender opening in the second side of the bonding head; a recessed surface, which is laterally outward from the first channel at least partially around the periphery of the bonding head, the recessed surface being positioned to be recessed from the second side of the bonding head; a second port extending from the first side of the bonding head toward the recessed surface; and a second channel, which is fluidically coupled to the second port and extends in a lateral direction along the recessed surface, at least partially surrounding the first channel, the second channel forming an elongated opening in the recessed surface; and a first flow unit, which is fluidically coupled to the bonding head and is configured to extract fluid from one or more of the first channel and the second channel.

[0005] On the other hand, the present application provides a semiconductor processing tool, comprising: a bonding head having a port extending from a first side of the bonding head toward a second side; and a first channel, which is fluidically coupled to the port and extends from the port in a lateral direction along the second side toward the periphery of the bonding head, the first channel forming an elongated opening in the second side of the bonding head; a vacuum manifold, which has a first conduit extending along one side of the bonding head, the first conduit having a first vacuum opening positioned laterally outward from the bonding head; and a first flow unit, which is fluidically coupled to the bonding head and is configured to extract fluid from one or more of the first channel and the first conduit.

[0006] On the other hand, the present application provides a method for inhibiting evaporated bonding materials from entering a vacuum system, the method comprising: extracting air from a first port of a bonding head via a first flow unit, wherein the first port fluid is coupled to a first channel of the bonding head, the first channel extends in a lateral direction from the port along a second side toward the periphery of the bonding head, and the first channel forms an elongated opening in the second side of the bonding head; and extracting air from a second port via a second flow unit, wherein the second port fluid is coupled to a second conduit positioned laterally outward from the first channel, so that contaminants flow into the second channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1A is a bottom plan view of a bond head configured in accordance with selected embodiments of the present technology, and Figure 1B and 1C is included Figure 1A A cross-sectional side view of a semiconductor processing tool showing a bond head is shown.

[0008] Figure 2A is a bottom plan view of a bond head configured in accordance with selected embodiments of the present technology, and Figure 2B is included Figure 2AA cross-sectional side view of a semiconductor processing tool showing a bond head is shown.

[0009] Figure 3 is a schematic diagram of a flow cell system configured in accordance with selected embodiments of the present technology. DETAILED DESCRIPTION

[0010] The technology disclosed herein relates to semiconductor devices, systems having semiconductor devices, and related methods for manufacturing semiconductor devices. The term "semiconductor device" generally refers to a solid-state device containing one or more semiconductor materials. Examples of semiconductor devices include logic devices, memory devices, and diodes. In addition, the term "semiconductor device" can refer to a finished device or a component or other structure at various processing stages before becoming a finished device.

[0011] Depending on the context in which it is used, the term "substrate" may refer to a structure that supports electronic components (e.g., a die), such as a wafer-level substrate, or to a singulated die-level substrate, or another die for die stacking applications. One of ordinary skill in the relevant art will recognize that the appropriate steps of the methods described herein may be performed at the wafer level or at the die level. In addition, unless the context otherwise indicates, the structures disclosed herein may be formed using conventional semiconductor manufacturing techniques. For example, chemical vapor deposition, physical vapor deposition, atomic layer deposition, spin coating, electroplating, and / or other suitable techniques may be used to deposit materials. Similarly, materials may be removed, for example, using plasma etching, wet etching, chemical mechanical polishing, or other suitable techniques.

[0012] The term "bonding head" may refer to an upper / lower chuck or tool used to mount a semiconductor die onto a substrate. A person skilled in the relevant art will also understand that the technology may have additional embodiments and that the technology may be used without the following references. Figures 1A to 3 The present invention is implemented without the need for several details of the embodiments described herein. A person skilled in the relevant art will recognize that appropriate steps of the methods described herein can be performed at the wafer level or the die level. In addition, unless the context indicates otherwise, the structures disclosed herein can be formed using conventional semiconductor manufacturing techniques.

[0013] The descriptions and illustrations herein of the shapes and configurations of the supplemental vacuum are exemplary and should not be construed as limiting the scope of the present disclosure. In this regard, in several embodiments, the shape of the supplemental vacuum pattern is any shape suitable for generating a sufficient vacuum at the location where the evaporated contaminants are generated. Likewise, in other embodiments, the supplemental vacuum may be applied to the TCB process without the use of a recessed flange or a separate vacuum manifold.

[0014] In several embodiments, the semiconductor die includes at least one contact exposed on the surface (e.g., a portion of a bonding pad or TSV extending through the die). In these embodiments, the interconnect structure is electrically coupled by bonding to the contact to allow electrical connections to be made with other components of the semiconductor device. To form this bond, the chip mounting device picks up the semiconductor device via a bonding head by evacuating a vacuum. The device then transfers the semiconductor device to a bonding area where the semiconductor device is bonded to a substrate or another semiconductor device. Embodiments of the present technology are applicable to any thermal compression bonding process, such as sequential bonding, collective bonding, group bonding, etc.

[0015] Thermal compression bonding (TCB) of semiconductor die stacks typically includes holding a representative semiconductor die on a bonding head with a vacuum drawn through a vacuum line. The semiconductor die is then transported to a position on a substrate under vacuum for bonding. A bonding material is disposed between the semiconductor die and the substrate to form a connection. Heat is applied by the bonding head to melt the bonding material and flow the bonding material, thereby mechanically and electrically connecting the semiconductor die to the substrate. Since there may be a gap between the bonding head and the interface surface of the semiconductor die, steam from the overheated bonding material may (a) enter the vacuum line during bonding and condense within the vacuum line, (b) travel upward and deposit on the exposed surface of the bonding head and thereby contaminate the exposed surface of the bonding head, wherein the bonding head extends beyond the surface area of ​​the semiconductor die, and / or (c) travel to other components of the adjacent semiconductor die stack and device. This steam may also be deposited on other surfaces of the bonding head that do not physically contact the semiconductor die.

[0016] The TCB process is performed at an elevated temperature to ensure that the bonding material reaches the required internal temperature to reliably form the interconnect, and higher temperatures are required to produce the interconnect bond when more dies are assembled in a high density die stack (e.g., 4, 6, 8, or more dies in a stack). In this regard, when bonding stacks of semiconductor dies, such as stacks having more than 4 dies, or when bonding stacks of semiconductor dies having a thicker top die to prevent solder fillet contamination, the higher temperatures required for bonding result in more evaporation (outgassing) of the bonding material.

[0017] This contamination causes various problems in the bonding of traditional semiconductor devices. In one example, the contamination may cover the stacking benchmarks on the adjacent semiconductor die stacks and cause identification problems and / or cause die misalignment during the manufacture of the semiconductor device. Contamination may also cause the semiconductor die to stick to the bonding head and / or contaminate the semiconductor die itself. Under a certain degree of contamination, the bonding head must be replaced, resulting in shutdown of the manufacturing process and increased costs. Among other problems, contamination may affect the under-bump metal (UBM) pads on the back of the semiconductor die, resulting in poor interconnect quality, such as non-wetting, cold welding, interconnection disconnection, defective and / or high resistance interconnection. The above-mentioned contamination is particularly suitable for three-dimensional integration (3DI) TCB processes of memory semiconductor devices (HBM, COW, 3DI DDR5, etc.); however, any TCB process for semiconductor devices is susceptible to the contamination described herein.

[0018] Although FAB tape can be used to reduce NCF / NCP contamination in TCB operations, TCB process capabilities are often limited by the use of FAB tape. For example, many commercially available FAB tapes have a maximum temperature of about 300°C, which is too low for bonding a die stack with several dies. Thus, the use of FAB tape limits the height of semiconductor die stacks that can be bonded using conventional methods. In one specific example, to form interconnects across a die stack having eight semiconductor dies, the required heat may result in a local temperature of about 400°C due to heat loss through multiple layers and FAB tape.

[0019] In an embodiment of the present technology, in addition to maintaining a vacuum for the semiconductor die of the bonding head, a supplementary vacuum source is also applied. The supplementary vacuum is expected to reduce the above-mentioned contamination and provide other advantages. For example, the supplementary vacuum is configured to inhale and retain degassed vapors that cause NCF / NCP contamination in the TCB process. In this regard, the supplementary vacuum can at least inhibit vapor from coating the bonding head or adjacent components of the semiconductor device. In some embodiments, the supplementary vacuum is arranged at one or more locations near the periphery of the bonding head, close to the interface between the bonding head and the semiconductor die, so that the supplementary vacuum inhales steam during the TCB process. In these embodiments, the configuration of the supplementary vacuum is adjacent to the bonding head; however, in other embodiments, the supplementary vacuum can be sucked from the bonding head by a separate vacuum manifold, as described in more detail below.

[0020] Among other advantages over conventional techniques, the supplemental vacuum TCB process described herein may provide improved die placement accuracy due to clearer fiducial identification; improved die stack reliability by reducing solder non-wetting, cold solder joints, interconnect breaks, defective or higher resistance interconnects; extended equipment and bond head life; lower cost; and higher process capability for group bonding without the need for FAB tape. Configurations of the present technology may be described herein with reference to TSV and / or three-dimensional integration (3DI); however, the present technology is also applicable to other interconnect types, particularly including flip chip bonding (FC), direct chip attach (DCA), and D2S. The description of the present technology in conjunction with a specific configuration should not be construed as limiting the application of the present technology.

[0021] Figure 1A is a bottom plan view of an embodiment of a bond head 102 in accordance with an embodiment of the present technology, and Figure 1B and 1C is a cross-sectional side view of an embodiment of a semiconductor processing tool 100 ("tool 100") and 110 ("tool 110") implementing a bond head 102. Referring first to FIG. Figure 1B , tool 100 includes a first vacuum conduit 122, a first flow unit 130 fluidly coupled to the first vacuum conduit 122, a second conduit 124, and a second flow unit 132 fluidly coupled to the second conduit 124. The first vacuum conduit 122 and the second conduit 124 are fluidly coupled to a bond head 102. During a TCB process, bond head 102 is operably positioned over a semiconductor die 140 ("die 140") having a front side 142 and a back side 144 opposite to front side 142. During bonding according to some embodiments, at least a portion of front side 142 of die 140 contacts second side 108 of bond head 102 while back side 144 of die 140 is bonded to substrate 160 with a bonding material 152 (e.g., non-conductive film (NCF), non-conductive paste (NCP), or wafer level underfill (WLUF) material, etc.). Those skilled in the art will appreciate that in other embodiments, bond head 102 may similarly contact back side 144 of die 140 instead of front side 142. Bonding material 152 may be applied at the wafer level and thus may be present on die 140 at bottom side 144 before die 140 is picked up by bond head 102.

[0022] The bonding head 102 has a first side 104 and a second side 108 opposite the first side 104. Figure 1A , 1BAs shown in conjunction with 1C, the bonding head 102 can include a first vacuum port 116, a first vacuum channel 112, and a second vacuum channel 114 fluidly coupled to the first vacuum port 116. Any number of first vacuum channels and second vacuum channels can be fluidly coupled to the first vacuum port 116, such as in Figure 1A In the illustrated embodiment, the first vacuum channel 112 and the second vacuum channel 114 may be grooves or trenches arranged in a pattern on the second side 108 of the bond head 102. The groove or trench profile allows the first vacuum channel 112 and the second vacuum channel 114 to form at least substantially closed channels when placed on or at least close to the abutting surface of the die 140 during the TCB process. Figure 1A The illustrated embodiment depicts one arrangement of first vacuum channels 112 and second vacuum channels 114; however, the vacuum channels may be arranged in any suitable pattern to apply vacuum on the die. For example, the first vacuum channels and second vacuum channels may have channels of any length, width, depth, and number to adequately apply vacuum on the second side 108 and interface with the front side 142 or the back side 144 to hold the die 140 during the TCB process. For example, the pattern of the vacuum channels may be configured to provide sufficient vacuum holding force for a particular type of semiconductor device being bonded by the TCB process, such as the weight of the device based on the number, thickness, size, etc. of dies in the stack.

[0023] like Figure 1B and 1C As shown, first vacuum port 116 extends from first side 104 of bonding head 102 to a first intermediate depth of bonding head 102, and first vacuum channel 112 and second vacuum channel 114 extend from second side 108 of bonding head 102 to the first intermediate depth to meet and form a fluid coupling with first vacuum port 116. First vacuum port 116 and first vacuum channel 112 and second vacuum channel 114 together comprise a first opening extending through bonding head 102, which is fluidically coupled to first flow unit 130 via first vacuum conduit 122. In some embodiments, first vacuum channel 112 and second vacuum channel 114 may not have uniform depths in bonding head 102.

[0024] In some embodiments, during the TCB process, the first opening is generally centered over the center point of the die 140; however, the first opening may be configured to maintain a certain degree of misalignment of the die 140, i.e., offset from the axis of the first vacuum port 116 and the center point of the die 140. The first flow unit 130 is configured to draw a vacuum between the bond head 102 and the die 140 by drawing a first fluid (e.g., air) at a first pressure (P1) through the first vacuum port 116 and the first vacuum channel 112 and the second vacuum channel 114. The first pressure (P1) may be less than about 0.1 megapascals (MPa), may be in the range of about 3 Pascals (Pa) to about 0.1 MPa, or may be other suitable pressures.

[0025] The bonding head 102 may further include a flange or step around the periphery of the bonding head, which is recessed from the surface of the die interface during the TCB process, such as a recessed flange 106 extending from the second side 108 to a certain depth in the bonding head 102 and arranged at least partially around the periphery of the bonding head 102. In these embodiments, the recessed flange or step provides a gap with the adjacent die stack during bonding and reduces the heat transfer to these adjacent die stacks. In this configuration, the evaporated contaminants are sucked in by the supplementary vacuum to avoid coating on the adjacent parts of the bonding head or semiconductor. For example, the recessed flange 106 can be recessed from the edge of the bonding head 102 toward the axis of the first vacuum port 116. The recessed flange 106 can have any appropriate depth from the second side 108 and any appropriate recess from the edge toward the axis of the first vacuum port 116 to prevent interference with adjacent semiconductor die stacks during the TCB process. In the embodiment shown, the recessed flange 106 is generally orthogonal and is recessed a uniform distance from each edge of the bonding head 102. Alternatively, recessed flange 106 may have other shaped surfaces and may be recessed from each edge by any suitable distance or any suitable profile, which may be different for each edge independently.

[0026] The bond head 102 further includes a second vacuum port 120 and a second vacuum channel 128 fluidly coupled to the second vacuum port 120. The second vacuum channel 128 may be a groove or trench in the recessed flange 106 of the bond head 102 extending at least partially around the perimeter of the bond head 102. The second vacuum port 120 extends from the first side 104 of the bond head 102 toward the recessed flange 106 to a second intermediate depth, and the second vacuum channel 128 extends from the recessed flange 106 of the bond head 102 to the second intermediate depth to meet the second vacuum port 120. The second vacuum port 120 and the second vacuum channel 128 together comprise a second opening extending through the bond head 102. The second vacuum channel 128 surrounds the first vacuum channel 112 and the second vacuum channel 114 such that the second vacuum channel 128 is positioned outward from the first vacuum channel 112 and the second vacuum channel 114. In the illustrated embodiment, the second vacuum channel 128 has a square cross-sectional profile, but it may be other suitable shapes (eg, V-shaped, arc-shaped, etc.) to distribute vacuum around the die 140 and to draw vapor from the TCB process.

[0027] exist Figure 1B In the embodiment of the present invention, the tool 100 has a second opening fluidically coupled to the second flow unit 132 and is generally positioned above the peripheral portion of the tube core 140 along the recessed flange 106. The second flow unit 132 is configured to extract a second fluid from the second vacuum channel 128 and the second vacuum port 120 under a pressure (P2). The second pressure (P2) can be less than about 0.1 MPa, or about 3 Pa to 0.1 MPa. In some embodiments, the magnitude of the second pressure (P2) is independent of the magnitude of the first pressure (P1). During the TCB process, the magnitude of the pressure P1 is configured to hold the tube core 140 (e.g., the tube core stack) when the bonding head 102 moves the tube core 140 to a position above the substrate 160 for bonding. In these embodiments, the magnitude of the pressure P1 is high enough to account for uneven topography of the surface of the semiconductor device, which may affect the ability of the bonding head 102 to form an airtight seal with the tube core 140.

[0028] exist Figure 1C In the tool 110, the tool 100 of the second flow unit 132 is omitted. In the tool 110, the first flow unit 130 is fluidly coupled to the first vacuum conduit 122 and the second vacuum conduit 124, and is configured to simultaneously or sequentially extract the first fluid from the first vacuum port 116 and the second fluid from the second vacuum port 120. In the embodiment where the first flow unit 130 extracts the first fluid and the second fluid simultaneously, one or more valves may be included in one or both of the first vacuum conduit 122 and the second vacuum conduit 124 to apply the first pressure P1 and the second pressure P2. Figure 1C, a first valve 162 is located in the first vacuum conduit 122, and a second valve 164 is located in the second vacuum conduit 124. The first valve 162 and the second valve 164 are configured to provide simultaneous balanced or different pressures between the first vacuum port 116 and the second vacuum port 120. In an embodiment where the first flow unit 130 sequentially draws the first fluid and the second fluid, the first valve 162 and the second valve 164 may be cycled to alternate flows between the first vacuum port 116 and the second vacuum port 120. The cycling of the first valve 162 and the second valve 164 may be configured such that the first pressure P1 and the second pressure P2 are applied separately, simultaneously, or any combination thereof.

[0029] As previously mentioned, second flow unit 132 is configured to extract second fluid from second vacuum channel 128 and second vacuum port 120, and second vacuum channel 128 and second vacuum port 120 are respectively outward from the periphery of first vacuum channel 112, second vacuum channel 114 and first vacuum port 116. In this arrangement, extracting second fluid at least partially prevents the bonding material of evaporation from entering the first opening. For example, in one embodiment, negative pressure is produced at the periphery of first vacuum channel 112 and second vacuum channel 114, and the negative pressure has produced the path for extracting the bonding material of evaporation before it arrives the first opening. In this embodiment, preferably at least a portion of the bonding material of evaporation is extracted by second vacuum channel 128 and second vacuum port 120 rather than by first vacuum channel 112 and second vacuum channel 114 and first vacuum port 116. In some embodiments, the second conduit 124 may have one or more filter units 126 (eg, mesh screens) configured to capture evaporated bonding material 152 and thereby prevent any captured evaporated bonding material from contaminating the second conduit 124 and / or the second flow unit 132 .

[0030] In certain embodiments, the second conduit 124 can be replaced in a relatively short time and / or at a relatively low cost. The second conduit 124 can be a replaceable tube that is configured to retain evaporated pollutants and is discarded at a certain time interval or detected pollutant accumulation level. The replaceable tube can include one or more pollutant collection features (such as coils or filters) to retain evaporated pollutants. In this regard, any suitable method can be used to monitor the vacuum flow rate of the supplementary vacuum for a value below the control limit, which will indicate the need to replace the supplementary vacuum tube. In some embodiments, a single supplementary vacuum tube is used to evacuate; however, any number of supplementary vacuum tubes can be used to evacuate and retain evaporated pollutants, for example, tubes positioned on each side of the joint head and each corner of the joint head.

[0031] Figure 1AThe illustrated embodiment has a first vacuum channel 112 and a second vacuum channel 114 extending generally radially outward from a first vacuum port 116. For example, the first vacuum channel may extend toward each corner of the bonding head 102, and the second vacuum channel 114 may extend generally orthogonally from the first vacuum port 116 to the edge of the bonding head 102. The first vacuum channel 112 and the second vacuum channel 114 are substantially mirror-symmetric at the horizontal midpoint of the bonding head 102. This configuration of the first vacuum channel 112 and the second vacuum channel 114 is expected to cover sufficient surface area of ​​the second side 108 of the bonding head 102 to ensure that the air drawn through the first vacuum channel 112 and the second vacuum channel 114 provides sufficient suction to hold the die 140 to the bonding head 102. For example, the first vacuum channel 112 and the second vacuum channel 114 may have a larger lateral dimension than the first vacuum port 116. The larger lateral dimension may cover a larger surface area of ​​the die 140 to help better secure the die 140 to the bonding head 102 once the vacuum is drawn via the first flow unit 130. In other embodiments, the first vacuum channel 112 and the second vacuum channel 114 are omitted, so that the first pressure P1 is applied directly to the die 140 through the first vacuum port 116 . Figure 1A The configuration of first vacuum channel 112 and second vacuum channel 114 shown in is intended to represent non-limiting examples of possible bond head designs that may be configured in accordance with the present technology. One of ordinary skill in the art will appreciate that additional bond head designs may be included and configured in accordance with the present technology.

[0032] The configuration of the second vacuum port 120 and the second vacuum channel 128 may be different from Figure 1A As another example, Figure 1A The illustrated embodiment includes only a single port to apply vacuum to the second fluid from the second vacuum channel 128. In other embodiments, additional ports may be provided to better ensure that the vacuum is evenly distributed throughout the second vacuum channel 128. For example, an additional second port (not shown) that is fluidly coupled to the second vacuum channel 128 and the second flow unit 132 may be included at the opposite end of the bonding head 102. As another example, instead of the second vacuum channel 128 completely surrounding the first vacuum channel 112 and the second vacuum channel 114, the second vacuum channel 128 may only surround a portion of the first vacuum channel 112 and the second vacuum channel 114. For example, the second vacuum channel 128 may only surround the upper and lower portions of the first vacuum channel 112 and the second vacuum channel 114, or the second vacuum channel 128 may be located in other areas where the evaporated bonding material is more likely to enter the first vacuum channel 112 and the second vacuum channel 114.

[0033] Figure 2A and 2BAn embodiment of a semiconductor processing tool 200 of the present technology ("tool 200") is shown. Figure 2A and 2B Certain features of the tool 200 shown in FIG. 1 are similar to features of the tool 100 described above, and therefore, unless otherwise noted, features of the tool 200 are referred to in the 200 series, with like numbers in the 200 series corresponding to similar features of the tool 100 referred to in the 100 series.

[0034] First reference Figure 2B , tool 200 includes a bond head 202 and a first flow cell 230 fluidly coupled to bond head 202 via a first vacuum conduit 222. During TCB processing, bond head 202 can be operably positioned over semiconductor die 240 ("die 240") such that at least a portion of a front side 242 of die 240 contacts a second side 208 of bond head 202 while a back side 244 of die 240 is bonded to substrate 260 with a bonding material 252. Bond head 202 includes a first vacuum port 210 and a plurality of first vacuum channels 212 and second vacuum channels 214 fluidly coupled to first vacuum port 210. First vacuum channels 212 and second vacuum channels 214 can be grooves or trenches arranged in a pattern on second side 208 in a manner similar to bond head 102. The plurality of first vacuum channels 212 and second vacuum channels 214 are configured to apply a vacuum on second side 208 and interface with front side 242 or back side 244 to hold die 240 during the TCB process.

[0035] Bond head 202 includes similar features as bond head 102 described above, except that Figures 1A to 1C In addition to the recessed flange 106 shown, the second vacuum port 120 and the second vacuum channel 128 are omitted and replaced by the first supplementary conduit 220 and the second supplementary conduit 228 (in Figure 2A ). The first supplemental conduit 220 and the second supplemental conduit 228 are separate from the bonding head 202 and are disposed around the periphery thereof. Figure 2A, first supplemental conduits 220 and second supplemental conduits 228 may be arranged in a manifold at locations around the bond head 202, and they are configured to extract fluids (e.g., air and vapor) from an area around the bond head 202 and the die 240 during TCB processing. In the illustrated embodiment, the first supplemental conduits 220 are located near a center point along an edge of the bond head 202, and the second supplemental conduits 228 are located near each corner of the bond head 202. The illustrated embodiment has four first supplemental conduits 220 and second supplemental conduits 228 each, and in other embodiments, any suitable number of first supplemental conduits 220 and second supplemental conduits 228 may be used in accordance with the present technology, including fewer or more conduits than the illustrated embodiment. In further embodiments, the tool 200 may omit first supplemental conduits 220 or second supplemental conduits 228 entirely, or the conduits may be placed at one or more locations depending on the concentration of vapor degassing in the TCB process.

[0036] The first supplemental conduit 220 and the second supplemental conduit 228 are fluidically coupled to the second flow unit 232 via the second conduit 224, which may be a single plenum or a single conduit. These individual conduits may be arranged such that the openings of the conduits are positioned around a peripheral portion of the die 240. As with the recessed flange 106 of the bond head 102, in some embodiments, the first supplemental conduit 220 and the second supplemental conduit 228 have ends with openings located above the second side 208 of the bond head 202 to provide clearance from adjacent semiconductor devices. The operation of the tool 200 in the TCB process is substantially similar to the tool 100 described herein, and this operation of the tool 200 will not be described in detail.

[0037] Figure 1A and 1B The semiconductor processing tool 100 shown in Figure 1C The tool 110 shown in Figure 2A and 2B The tool 200 shown in can be operated by activating the first flow unit 130 to reduce the pressure in the first opening so that at least a portion of the tube core 140 contacts at least a portion of the second side 108 of the bonding head 102. As soon as the tube core 140 contacts the bonding head 102, at least a partial seal is formed at the interface between the tube core 140 and the bonding head 102. Once established, the seal can be maintained even after the first flow unit 130 (i.e., the vacuum unit) is deactivated. Thus, in some embodiments, the first flow unit 130 does not need to be operational during the entire time that the tube core 140 is bonded to the substrate 160. Deactivating the first flow unit 130 during the bonding process reduces the driving force that draws the evaporated bonding material through the first opening and into the first vacuum conduit 122 and / or the first flow unit 130.

[0038] In the TCB process, the second flow unit 132 is activated to draw the second fluid from the second opening (or the first valve 162 and the second valve 164 in the tool 110). Because in the illustrated embodiment, the second opening is peripheral to the first opening and surrounds at least a portion of the first opening, the second fluid draws in surrounding fluid (e.g., air and contaminants from degassing) from the outer portion of the die 140 compared to the first fluid drawn through the first opening. Thus, in operation, the second fluid provides a less-resistance path around the first opening that draws in evaporated material from around the bond head 102 and the front side 142 of the die 140.

[0039] First flow unit 130 and second flow unit 132 may remain operational as bonding material 152 diffuses to the periphery of bottom side 144 of die 140. In this manner, second flow unit 132 may continue to draw the second fluid from the outer portion of die 140 and provide a vacuum around die 140 that draws in vaporized bonding material 152 and prevents such material from traveling between second side 108 of bond head 102 and front side 142 of die 140 and entering first vacuum port 116. In some embodiments, fillets 152 of bonding material 152 may be formed on the outer portion of die 140; however, the thickness of die 140 may be configured to prevent bond head 102 from being contaminated by fillets 152.

[0040] Figure 3 A schematic diagram of a flow system 100 for extracting fluid from a bonding head 102 is shown. The flow system 100 includes a first flow unit 130 configured to extract fluid from the bonding head 102 and a second flow unit 132 configured to extract fluid from the bonding head 102. The first flow unit 130 includes a vacuum unit 170, a first recirculation valve 178, a first exhaust valve 176a, a first inlet valve 176b, and a first pressure sensor 174. In some embodiments, the first flow unit 130 is coupled to the bonding head 102 via a first vacuum conduit 122. The vacuum unit 170, valves 178, 176a and 176b, and the pressure sensor 174 can each be operably connected to a controller 172 for controlling the flow through the vacuum unit 170 to maintain a specific pressure (e.g., P1). For example, the controller 172 can maintain a specific pressure by opening and / or closing valves 178, 176a, and 176b according to the current value of the first pressure sensor 174.

[0041] The second flow unit 132 includes a vacuum unit 180, a second recirculation valve 188, a second inlet valve 186a, a second exhaust valve 186b, and a second pressure sensor 184. The second flow unit 132 is coupled to the bonding head 102 via the second conduit 124. The vacuum unit 180, valves 188, 186a and 186b, and the second pressure sensor 184 can each be operably connected to a controller 182 for controlling the flow through the vacuum unit 180 to maintain a specific pressure (e.g., P2). In some embodiments, the controllers 172 and 182 can be connected to a main controller (not shown) to provide better control pressure of the fluid extracted from the bonding head 102. One of ordinary skill in the art will recognize that other flow units and / or valve arrangements can be used to perform similar functions as described herein.

[0042] The present disclosure is not intended to be exhaustive or to limit the present technology to the precise form disclosed herein. Although specific embodiments are disclosed herein for the purpose of illustration, various equivalent modifications are possible without departing from the present technology, as will be appreciated by those of ordinary skill in the relevant art. For example, although the specification focuses on the use of NCF, NCP and / or WLUF thermocompression bonding, the present technology may also be applied to other processes and / or applications, such as flux for microbump formation and flip chip. In some cases, well-known structures and functions are not shown or described in detail to avoid unnecessarily obscuring the description of the embodiments of the present technology. Although the steps of the method present the steps of the method in a particular order, alternative embodiments may perform the steps in a different order. Similarly, certain aspects of the present technology disclosed in the context of a particular embodiment may be combined or eliminated in other embodiments. In addition, although advantages associated with certain embodiments of the present technology may have been disclosed in the context of those embodiments, other embodiments also exhibit such advantages, and not all embodiments need to exhibit such advantages or other advantages disclosed herein to fall within the scope of the present technology. Therefore, the present disclosure and related technologies may include other embodiments not explicitly shown or described herein.

[0043] As used herein, the terms "vertical", "lateral", "upper", "lower" may refer to the relative direction or position of a feature in a semiconductor device taking into account the orientation shown in the accompanying drawings. For example, "upper" or "uppermost" may refer to a feature that is positioned closer to the top of the page than another feature. However, these terms should be broadly interpreted to include semiconductor devices with other orientations, such as inverted or tilted orientations, where top / bottom, above / below, above / below, up / down, left / right, and distal / proximal can be interchanged depending on the orientation. In addition, for ease of reference, the same figure numbers are used in this disclosure to identify similar or similar parts or features, but the use of the same figure numbers does not mean that these features should be interpreted as being the same. In fact, in many of the examples described herein, the features of the same number have multiple embodiments that are different from each other in structure and / or function. In addition, the same shading can be used to indicate that the materials in the cross-section can be similar in composition, but the use of the same shading does not mean that the materials should be interpreted as being the same unless explicitly stated herein.

[0044] The present disclosure can also quote quantity and number.Unless otherwise specified, these quantity and number are not considered to be restrictive, but examples of possible quantity or quantity related to the new technology.In addition, in this regard, the present disclosure can use the term "multiple" to refer to quantity or number.In this regard, the term "multiple" refers to any number more than one, such as two, three, four, five, etc.For the purpose of the present disclosure, the phrase "at least one of A, B and C" refers to, for example, (A), (B), (C), (A and B), (A and C), (B and C) or (A, B and C), including all further possible arrangements when listing more than three elements.

[0045] It will be appreciated from the foregoing that specific embodiments of the new technology have been described herein for illustrative purposes, but various modifications may be made without departing from the present disclosure. Therefore, the present invention is limited only by the appended claims. In addition, certain aspects of the new technology described in the context of specific embodiments may also be combined or eliminated in other embodiments. In addition, although the advantages associated with certain embodiments of the new technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need to exhibit such advantages to fall within the scope of the present disclosure. Therefore, the present disclosure and related technologies may include other embodiments not explicitly shown or described herein.

Claims

1. A method for inhibiting vaporized bonding material from entering a vacuum system, the method comprising: extracting air from a first port of a bond head via a first flow unit, the bond head having a first side and a second side spaced a distance from the first side and defining a thickness of the bond head, wherein the first port is fluidly coupled to a first channel of the bond head, the first channel extending in a lateral direction from the port along the second side toward a periphery of the bond head, the first channel forming an elongated opening in the second side of the bond head; as well as extracting air from a second port via a second flow unit, wherein the second port is fluidly coupled to a second conduit positioned laterally outward from the first channel such that contaminants flow into the second conduit, The second conduit is a vacuum manifold separated from the bonding head and arranged around the bonding head, the vacuum manifold has a portion extending along a side of the bonding head and spaced apart from the side of the bonding head, the portion is positioned laterally outward from the periphery of the bonding head, and the second conduit has a second vacuum opening positioned laterally outward from the bonding head. 2 . The method of claim 1 , wherein the first flow unit comprises a vacuum unit that generates a first pressure in the first channel, and wherein the second flow unit comprises a vacuum unit that generates a second pressure in the second conduit. The method according to claim 2 , wherein an absolute value of the first pressure is greater than an absolute value of the second pressure. 4 . The method of claim 1 , wherein the bond head is positioned over the die and the bonding material, and wherein extracting air from the second conduit at least partially prevents evaporated bonding material from entering the first channel.

5. The method according to claim 1, further comprising: positioning the bond head over the die at least partially surrounded by the bonding material, Wherein extracting air through the second flow unit includes preventing vapor from the bonding material from flowing through the first port.

6. The method according to claim 1, wherein: the first port extends from the first side of the bond head to an intermediate depth of the bond head, and The first channel extends from the second side of the engagement head to the intermediate depth of the engagement head.

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