TWI791013B - Methods for ultrasonically bonding semiconductor elements - Google Patents

Abstract

A method of ultrasonically bonding semiconductor elements includes the steps of: (a) aligning surfaces of a plurality of first conductive structures of a first semiconductor element to respective surfaces of a plurality of second conductive structures of a second semiconductor element; and (b) ultrasonically bonding ones of the first conductive structures to respective ones of the second conductive structures. A bonding surface of at least one of the first conductive structures and the second conductive structures includes a frangible coating.

Description

Method for ultrasonic bonding of semiconductor components

The present invention relates to the formation of semiconductor packages, and more particularly to improved systems and methods for bonding semiconductor components together.

Conventional semiconductor packaging typically includes a die attach process and a wire bonding process. In this industry, advanced semiconductor packaging technologies (eg, flip chip bonding, thermocompression bonding, etc.) are gaining more attention. For example, in thermocompression bonding, heat and pressure are used between semiconductor elements to form a plurality of interconnections.

While the use of advanced packaging technologies is increasing, there are a number of limitations in these technologies, including, for example, limitations related to the relative infancy of some advanced packaging technologies. Accordingly, it would be desirable to provide improved systems and methods for bonding semiconductor components together.

According to an exemplary embodiment of the present invention, there is provided a method of ultrasonically bonding a semiconductor element. The method includes the steps of: (a) aligning a plurality of surfaces of a plurality of first conductive structures of a first semiconductor element with a plurality of corresponding surfaces of a plurality of second conductive structures of a second semiconductor element; and (b) A plurality of first conductive structures among the first conductive structures are ultrasonically bonded to a corresponding plurality of second conductive structures among the second conductive structures. Prior to step (b), the bonding surface of at least one of the first conductive structures and the second conductive structures includes a friable coating.

For example, a frangible coating on the plurality of conductive structures of at least one first semiconductor component and at least one second semiconductor component may be applied prior to flip-chip bonding to protect the bonding surfaces of the conductive structures from oxidation (e.g., where The conductive structure may be formed of or include copper). The coating may be a surface layer composed of silicon nitride, silicon oxide or silicon carbide or mixtures thereof, the coating has a thickness suitable for bonding without fluxing, and the coating is used in ultrasonic bonding The action is friable enough to obtain a metal-to-metal contact between the conductive structures of the first semiconductor element and the second semiconductor element. An exemplary range of thickness of the coating is between 10 Angstroms (Angstroms, Å) and 500 Angstroms, and another exemplary range is between 15 Angstroms and 250 Angstroms. The coating may be, for example, a nitride, oxide or carbide of titanium, tantalum, indium, aluminum, tin, zinc, zirconium, vanadium, chromium, nickel.

A sufficiently brittle ceramic coating can be used to obtain a metal-to-metal contact between the bonding surfaces of the corresponding conductive structures during ultrasonic flip-chip bonding and to obtain a surface suitable for bonding without fluxing.

That is, the present invention provides a method to protect the bonding surface of a conductive structure (e.g., a copper conductive structure) for flip-chip bonding including an ultrasonic connection from contaminants such as copper oxide or migration from the bonding surface. Remove pollutants. The method includes coating the bonding surfaces with a layer of ceramic material having properties suitable for bonding without flux processing and providing the layer with sufficient frangibility to obtain a bond between the bonding surfaces of the conductive structures during flip-chip bonding. The thickness of the hardness of the metal-to-metal contact.

The coating of the conductive structure may be a surface coating composed of a rare earth metal that forms complexes with copper (eg, if the conductive structure comprising the coating is copper). The coating may have a thickness such that upon formation of the copper complex (e.g., exposure to a reducing environment containing hydrogen), a ceramic hydride layer (e.g., selected from the group consisting of metal hydrides of copper-rare earth metal complexes and forming metal hydrides) is formed. A layer of a metal hydride compound of a metal hydride of a hydride that does not fuse metal with copper), the ceramic hydride layer has a thickness suitable for bonding without flux treatment and provides the layer with the aforementioned hardness.

As used herein, the term "semiconductor element" means any structure that includes (or is configured to include in a subsequent step) a semiconductor wafer or die. Exemplary semiconductor components include bare semiconductor die, semiconductor die on a substrate (e.g., lead frame, PCB, carrier, etc.), packaged semiconductor device, flip-chip semiconductor device, die embedded in a substrate, made of semiconductor stacks of crystal grains, etc. Furthermore, the semiconductor elements may include elements configured to be bonded or otherwise included in a semiconductor package (eg, spacers, substrates, etc. incorporated in a stacked die configuration).

According to certain exemplary embodiments of the present invention, innovative techniques (and structures) for assembling semiconductor devices such as package on package (ie, package on package, PoP) structures are provided. For example, multiple semiconductor elements (which may be packages) may be arranged in a stacked structure. Each of these elements preferably comprises an aluminum (or aluminum alloy, or partially aluminum) conductive structure ultrasonically bonded together. This technology has certain advantages including, for example: reduced density compared to other interconnect technologies (e.g., solder-based PoP technology); no use of solder bump reflow as opposed to other interconnect technologies; and in some applications room temperature ultrasonic bonding is enabled by the use of aluminum-aluminum interconnects.

FIG. 1A shows a portion of an ultrasonic bonding machine 100 including a bonding tool 124 and a support structure 150 . As will be appreciated by those skilled in the art, a thermocompression bonding machine, such as machine 100 or any other machine embodiment described in this disclosure, may include many elements that are not shown in the figures for simplicity. Exemplary elements include, for example: a plurality of input elements for providing a plurality of input workpieces to be bonded to other semiconductor components; a plurality of output elements for receiving a plurality of processed workpieces, now including other semiconductor components; Conveyor system for moving multiple workpieces; imaging system for imaging and aligning multiple workpieces; bond head element carrying bonding tools; kinematic system for moving bond head elements; including software for operating the machine computer systems; and other components.

Referring again to FIG. 1A , the upper semiconductor component 108 is held by the holding portion 110 of the bonding tool 124 (eg, by a vacuum, such as by a vacuum port defined by the holding surface of the holding portion 110 ). The upper semiconductor device 108 includes upper conductive structures 112a and 112b on the lower surface thereof. Lower semiconductor component 160 includes semiconductor die 102 bonded to (or otherwise supported by) substrate 104 . Lower conductive structures 106 a and 106 b are disposed on the upper surface of the lower semiconductor die 102 . The substrate 104 is in turn supported by a support structure 150 (eg, a heat block of the machine 100, an anvil of the machine 100, or any other desirable support structure). In the structure shown in FIG. 1A (ready for bonding), each of the upper conductive structures 112a and 112b is generally aligned with the corresponding lower conductive structures 106a and 106b. The semiconductor component 108 is moved downward by movement of the bonding tool 124 (shown by arrow 126 in FIG. 1A ). After this movement, Figure IB shows the contact between the respective conductive structures 106a and 112a and 106b and 112b. Ultrasonic energy 114 is applied to the upper semiconductor element 108 through the bonding tool 124 using an ultrasonic transducer (not shown in the figure, but represented as an "ultrasonic generator, USG" in the figure, i.e. an ultrasonic generator) and upper conductive structures 112a and 112b. For example, an ultrasonic transducer carrying the bonding tool 124 may in turn be carried by a bonding head element of the machine 100 .

During ultrasonic bonding, the lower conductive structures 106a and 106b may pass through the support provided by the support structure 150 to the lower semiconductor element 160 (for example, the support surface of the support structure 150 may include one or more vacuum ports to hold the substrate during bonding). 104 is secured to a support structure 150) to remain relatively stationary. Ultrasonic energy 114 (along with optional bonding force and/or heat) may locally deform the conductive structure. For example, in FIG. 1C , conductive structures 106a and 106b and 112a and 112b are shown partially deformed. In FIG. 1C , an ultrasonic bond is formed between corresponding pairs of conductive structures. For example, ultrasonic bond 128a is formed between deformed conductive structures 112a'/106a', and ultrasonic bond 128b is formed between deformed conductive structures 112b'/106b'. Conductive structures 106a and 106b and 112a and 112b may be formed from aluminum or an aluminum alloy, or may include aluminum at their bonding surfaces, or the like.

Corresponding pairs of conductive elements 106a and 112a and 106b and 112b can be bonded together at room temperature (without adding heat during the bonding process). Optionally, additional heat may be applied, for example: (1) during the bonding process, by applying additional heat to the upper semiconductor element 108 via the bonding tool 124, thereby heating the upper conductive elements 112a and 112b; and/or (2) During the bonding process, additional heat is applied to the lower semiconductor element 160 through the support structure 150 (eg, heating block 150 ), thereby heating the lower conductive structures 106a and 106b. Such optional heating (eg, by bonding tools and/or support structures, etc.) is applicable to any embodiment of the invention shown and described herein.

The semiconductor elements 160 and 108 shown in FIGS. 1A-1C may be any of a plurality of semiconductor elements configured to be bonded together. In a particularly specific example (which is also applicable to other embodiments shown and described in this disclosure), semiconductor element 160 is a processor (e.g., also referred to as an application processor unit (APU) ) of the mobile phone processor), and the semiconductor element 108 is a memory device configured to be bonded to the processor as shown in FIGS. 1A to 1C .

The conductive structures shown in FIGS. 1A-1C (ie, 112a, 112b, 106a, 106b) are shown as generic structures. These structures can take many different forms, such as conductive posts, stud bumps (for example, formed using a stud bump machine), plated conductive structures, sputtered conductive structures, wire sections, bond pads, contact pads, and other form. Various other drawings provided herein show specific examples of these structures. According to some embodiments of the invention, the contact area (ie the bonding surface) of the conductive structure at which it is to be bonded to another conductive structure comprises aluminum. In these embodiments, the conductive structure may be formed of aluminum or an aluminum alloy (eg, alloyed aluminum with copper, alloyed aluminum with silicon and copper, etc.). In other examples, the conductive structure may include a base conductive material other than aluminum (eg, copper) and aluminum (or an aluminum alloy) in the contact region. In this application, if a conductive structure is referred to as "aluminum", it should be understood that the structure may be aluminum, may be an aluminum alloy, or may include aluminum (or an aluminum alloy) in the contact area of such a conductive structure.

FIG. 2A shows a portion of an ultrasonic bonding machine 200 including a bonding tool 224 and a support structure 250 . Upper semiconductor element 208 is held (eg, by vacuum) by holding portion 210 of bonding tool 224 and includes upper conductive structures 222a and 222b (ie, conductive aluminum pads 222a and 222b ) disposed at its lower surface. Lower semiconductor component 260 includes semiconductor die 202 bonded to (or otherwise supported by) substrate 204 . Lower conductive structures 206 a and 206 b are disposed on the upper surface of the lower semiconductor die 202 . Substrate 204 is in turn supported by support structure 250 . In the structure shown in FIG. 2A, each of the upper conductive structures 222a and 222b is generally aligned with (and configured for ultrasonic bonding to) the corresponding lower conductive structures 206a and 206b. 206b). The lower conductive structure 206 a includes a copper (Cu) pillar 230 disposed on an upper surface on the lower semiconductor die 202 and an upper aluminum contact structure 216 on an upper surface of the Cu pillar 230 . The upper aluminum contact structure 216 may, for example, be plated or sputtered onto the upper surface of the lower copper pillar 230 . FIG. 2B is an enlarged view of portion "B" of FIG. 2A and shows the top of the lower conductive structure 206a in contact with the upper conductive element 222a.

Ultrasonic energy is applied to the upper semiconductor device 208 through the bonding tool 224 using an ultrasonic transducer (not shown). As shown in Figure 2C, ultrasonic energy can locally deform the conductive structure. That is, an ultrasonic bond 228 is formed between the deformed upper conductive structure 222a' and the deformed contact structure 216' (as shown in FIG. 2C).

As will be appreciated by those skilled in the art, Cu pillars 230 (including plated or sputtered aluminum contact structures/portions 216) are but one example of a conductive structure comprising aluminum. FIG. 2A also shows another exemplary conductive structure 206b. The lower conductive structure 206b is an aluminum structure (or aluminum alloy structure) such as a portion of aluminum wire (which may be bonded using a wire bonding process), an aluminum pillar, or the like.

FIG. 3 shows a portion of an ultrasonic bonding machine 300 including a bonding tool 324 and a support structure 350 . The upper semiconductor element 308 is held by the holding portion 310 of the bonding tool 324 (eg, by vacuum) and includes upper conductive structures 322a and 322b (ie, conductive aluminum pads 322a and 322b ). FIG. 3 shows the bonding of packaged semiconductor device 360 (ie, lower semiconductor element 360 ) to upper semiconductor element 308 . Lower semiconductor element 360 includes semiconductor die 302 bonded to (or otherwise supported by) substrate 304 . The lower conductive structures 306 a and 306 b are disposed on the upper surface of the substrate 304 . Substrate 304 is in turn supported by support structure 350 . Wire loops 320a and 320b are bonded between semiconductor die 302 and substrate 304 (although not shown in FIG. supplement). A coating/encapsulation 334 (eg, epoxy molding compound) has been applied over the die 302 and the wire loops 320a and 320b. As shown, upper portions of the lower conductive structures 306 a and 306 b are exposed above the coating/encapsulation 334 to allow electrical connection to the upper semiconductor device 308 .

In the structure shown in FIG. 3, each of the upper conductive structures 322a and 322b is generally aligned with (and configured to ultrasonically bond to) the corresponding lower conductive structures 306a and 306b. 306b). As shown in FIG. 3, each of the lower conductive structures 306a and 306b includes a respective Cu pillar 330a and 330b on the upper surface of the substrate 304, and a respective upper aluminum contact structure 316a on the upper surface of the Cu pillars 330a and 330b. and 316b. Upper aluminum contact structures 316a and 316b may be plated or sputtered onto respective upper surfaces of Cu pillars 330a and 330b. As shown, semiconductor element 308 has been moved downward by movement of bonding tool 324 (as indicated by the arrow in FIG. 3 ), which shows contact between conductive structures 306a and 322a and 306b and 322b. Ultrasonic transducers are used to apply ultrasonic energy (along with optional heat and/or bonding force) to the upper semiconductor element 308 (e.g., via bonding tool 324) to form a bond between aluminum conductive structures 322a and 322b and corresponding An ultrasonic bond is formed between the aluminum contact structures 316a and 316b.

FIG. 4A shows a portion of an ultrasonic bonding machine 400 including a bonding tool 424 and a support structure 450 . The upper semiconductor element 408 is held by the holding portion 410 of the bonding tool 424 (e.g., by vacuum) and includes upper conductive structures 412a and 412b (i.e., e.g., sputtered aluminum bumps, aluminum stud bumps, etc.) disposed on its lower surface. wait). The lower semiconductor element 460 includes a semiconductor die 402 bonded to (or otherwise supported by) a support structure 404 (eg, an FR4 support structure). Lower conductive structures 406 a and 406 b (ie, eg, sputtered aluminum bumps, aluminum stud bumps, etc.) are disposed on the upper surface of the lower semiconductor die 402 . Substrate 404 is in turn supported by support structure 450 . In the structure shown in FIG. 4A, each of the upper conductive structures 412a and 412b is generally aligned with (and is configured to ultrasonically bond to) the corresponding lower conductive structures 406a and 406b. 406b). Figure 4B shows details of structures 412a and 406a (before ultrasonic bonding). Referring again to FIG. 4A , semiconductor element 408 has been moved downward by movement of bonding tool 424 (as indicated by the arrow in FIG. 4A ), so that contacts are shown between conductive structures 406a and 412a and 406b and 412b. Ultrasonic transducers are used to apply ultrasonic energy 414 (together with optional heat and/or bonding force) to the upper semiconductor element 408 (e.g., through a bonding tool 424) to deform the upper aluminum conductive structure and deform Ultrasonic joints 428a and 428b are formed between the corresponding lower aluminum contact structures of 20 (see, for example, complete ultrasonic joint 428a' formed between deformed structure 412a' and deformed structure 406a' shown in FIG. 4C ) .

FIG. 5A shows a portion of an ultrasonic bonding machine 500 including a bonding tool 524 and a support structure 550 . The upper semiconductor element 508 is held (eg, by vacuum) by the holding portion 510 of the bonding tool 524 and includes upper conductive structures 522a and 522b (ie, conductive aluminum pads 522a and 522b ). The lower semiconductor component 560 includes a semiconductor die 502 bonded to (or otherwise supported by) a substrate 504 (eg, an FR4 support structure). Lower conductive structures 506 a and 506 b (ie, eg, sputtered aluminum bumps, aluminum stud bumps, etc.) are disposed on the upper surface of the lower semiconductor die 502 . Substrate 504 is in turn supported by support structure 550 . In the structure shown in FIG. 5A, each of the upper conductive structures 522a and 522b is generally aligned with (and is configured to ultrasonically bond to) the corresponding lower conductive structures 506a and 506b. 506b). Figure 5B shows details of structures 522a and 506a (before ultrasonic bonding). As shown, semiconductor element 508 has been moved downward by movement of bonding tool 524 (as indicated by the arrow in FIG. 5A ), which shows contact between conductive structures 506a and 522a. Ultrasonic transducers are used to apply ultrasonic energy (along with optional heat and/or bonding force) to the upper semiconductor element 508 (e.g., through the bonding tool 524) to form a bond between the deformed upper aluminum conductive structure and the deformed Ultrasonic bonds 528a and 528b are formed between respective lower aluminum contact structures (see, eg, full ultrasonic bond 528a' formed between deformed structure 522a' and deformed structure 506a' shown in FIG. 5C).

FIG. 6A shows a portion of an ultrasonic bonding machine 600 including a bonding tool 624 and a support structure 650 . In FIG. 6A, a plurality of semiconductor devices are bonded together in a stacked structure according to the teachings of the present invention. Specifically, semiconductor element 660a includes semiconductor die 602a bonded to (or otherwise supported by) substrate 604a, with conductive structures 606a and 606b (i.e., such as sputtered aluminum bumps, aluminum stud bumps, etc.) are provided on the upper surface of the semiconductor die 602a. The semiconductor element 660 a is supported by the support structure 650 .

Another semiconductor element 660b (comprising corresponding semiconductor die 602b bonded to or otherwise supported by substrate 604b, and including conductive structures 612a and 612b on substrate 604b) has been previously bonded to semiconductor element 660a. Specifically, bonding tool 624 pre-bonds (eg, ultrasonically bonds) element 660b to element 660a such that ultrasonic bonds 628a and 628b are formed between respective pairs of aluminum conductive structures 612a and 606a and 612b and 606b. Element 660b also includes conductive structures 606a' and 606b', which have been bonded to the conductive structures of element 660c in steps described below. 6B shows a detailed view of ultrasonic joint 628a including deformed conductive structures 612a and 606a.

Similarly, yet another semiconductor element 660c (comprising corresponding semiconductor die 602c bonded to or otherwise supported by substrate 604c, and including conductive structures 612a' and 612b' on substrate 604c) has been previously bonded to Semiconductor element 660b. Specifically, bonding tool 624 pre-bonds (eg, ultrasonically bonds) element 660c to element 660b such that ultrasonic bonds are formed between respective pairs of aluminum conductive structures 612a' and 606a' and 612b' and 606b'. 628a' and 628b'. Element 660c also includes conductive structures 606a'' and 606b'' that will be bonded to the conductive structures of element 660d in steps described below.

As shown in FIG. 6A , upper semiconductor element 660d is held by holding portion 610 of bonding tool 624 (eg, by vacuum) and includes semiconductor die 602d bonded to (or otherwise supported by) substrate 604d. Conductive structures 612a'' and 612b'' (ie, eg, sputtered aluminum bumps, aluminum stud bumps, etc.) are disposed on the lower surface of the substrate 604d. The conductive structures 612a'' and 612b'' are generally aligned with (and configured to ultrasonically bond to) the corresponding conductive structures 606a'' and 606b''. The semiconductor element 66Od is moved downward by the movement of the bonding tool 624 (shown by the arrow in FIG. 6A). After this downward movement, contact occurs between corresponding pairs of conductive structures 612a" and 606a" and 612b" and 606b" (see, eg, between structures 612a" and 606a" of FIG. 6C Detailed view of the contact before deformation by ultrasonic bonding). Ultrasonic energy is applied to the upper semiconductor element 604d through the bonding tool 624 using an ultrasonic transducer (not shown in the figure) to form a bond between the corresponding pairs of conductive structures 612a'' and 606a'' and 612b'' and 606b. '' to form an ultrasonic joint.

Although specific exemplary upper and lower aluminum conductive structures have been illustrated, those skilled in the art will appreciate that various shapes and designs of upper and lower aluminum conductive structures are permitted within the teachings of the present invention.

FIG. 7 is a flowchart showing a method of bonding semiconductors together according to an exemplary embodiment of the present invention. As those skilled in the art understand, certain steps included in the flowcharts may be omitted; some additional steps may be added; and the order of the steps may be changed relative to the order shown. In step 700, a first semiconductor component (eg, comprising a semiconductor die on a substrate) is supported on a support structure of a bonder. The first semiconductor element (e.g., the upper surface of the semiconductor structure) includes a plurality of first conductive structures (see, e.g., structures 106a and 106b of element 160 in FIG. 1A; Structures 206a and 206b; structures 306a and 306b of element 360 in FIG. 3A; structures 406a and 406b of element 460 in FIG. 4A; structures 506a and 506b of element 560 in FIG. 5A; and the structure of element 660c in FIG. 6A 606a'' and 606b''). In step 702, a second semiconductor component is held by a holding portion of a bonding tool of a bonding machine (see, for example, components 108, 208, 308, 408, 508, and 660d in the corresponding figures). The second semiconductor element includes a plurality of second conductive structures at least partially composed of aluminum (eg, on a lower surface of the second semiconductor element). In step 704, the first conductive structure and the second conductive structure are aligned with each other (see, eg, FIGS. 1A and 6A ), and then brought into contact with each other. In optional step 706, the plurality of aligned first and second conductive structures are pressed together with a predetermined magnitude of bonding force. The engagement force of the predetermined magnitude may be a single engagement force value, or may be an engagement force profile in which an actual engagement force varies during an engagement operation. In optional step 708, heat is applied to the aligned plurality of first conductive structures and/or second conductive structures. For example, heat may be applied to the first conductive structure using a support structure supporting the first semiconductor element. Similarly, heat may be applied to the second conductive structure using a bonding tool holding the second semiconductor element. In step 710, a plurality of first and second conductive structures are ultrasonically bonded together to form an ultrasonic bond therebetween.

As will be appreciated by those skilled in the art, since the present invention joins aluminum material to aluminum material, this can readily be accomplished using ultrasonic energy and/or bonding force, typically without the need for heating, so when ambient temperature/relative The present invention is particularly beneficial for low temperature bonding operations.

While the present invention is primarily described and illustrated in relation to two pairs of conductive structures ultrasonically bonded together, the invention is of course not limited thereto. In fact, semiconductor packages assembled in accordance with the present invention (eg, advanced packages) may have any number of conductive structures, and may have hundreds (or even thousands) of pairs of conductive structures that are ultrasonically bonded together. Furthermore, the conductive structures do not need to be bonded in pairs. For example, one structure may be joined to two or more opposing structures. Thus, any number of conductive structures from one semiconductor component can be ultrasonically bonded to any number of conductive structures of another semiconductor.

While the present disclosure primarily describes (and illustrates) the application of ultrasonic energy through a bonding tool (eg, at the location where the bonding tool engages an ultrasonic transducer), the present invention is not limited thereto. Rather, ultrasound energy can be transmitted through any desired structure, such as a support structure.

As will be appreciated by those skilled in the art, the details of the ultrasonic bonding can vary widely depending on the particular application. Nonetheless, some non-limiting exemplary details are now described. For example, the frequency of the ultrasonic transducer can be designed in conjunction with the design of the conductive structure (for example, a column structure, etc.), so that the resonant frequency of the transducer is roughly consistent with the resonant frequency of a given semiconductor element, in this case , the conductive structure can act dynamically as a cantilever beam. In another exemplary alternative, the transducer can be operated out of resonance with respect to the semiconductor element in a simple "slave" type of manner.

Exemplary ranges of energy applied to an ultrasonic transducer (eg, to a piezoelectric crystal/ceramic in a transducer driver) may be in the range of 0.1 kHz to 160 kHz, 10 kHz to 120 kHz, 20 kHz to 60 kHz, etc. During engagement, a single frequency may be applied, or multiple frequencies may be applied (eg, sequentially, simultaneously, or both sequentially and simultaneously). The scrubbing of the semiconductor element (i.e., the vibrational energy applied to the semiconductor element held by the bonding tool) can be applied in any of a number of desired directions, and can be applied by the bonding tool holding the semiconductor element (as in the present invention). shown), applied by support structures supporting semiconductor elements, and other structures. With particular reference to the illustrated embodiment of the invention in which ultrasonic energy is applied by a bonding tool holding a semiconductor component, the scrubbing may be applied in a direction generally parallel or generally perpendicular to the longitudinal axis of the bonding tool (or in other directions) .

The vibrational energy applied by the ultrasonic transducer can be applied, for example, with a peak-to-peak amplitude range of 0.1 um to 10 um (e.g., using feedback control to constant voltage, constant current, or including but not limited to ramp current, ramp voltage Alternate control schemes, or proportional feedback control based on one or more inputs).

The bonding force may also be applied during at least a portion of the ultrasonic bonding cycle, as described herein. An exemplary range of engagement force is 0.1 kg to 100 kg. The engagement force may be applied as a constant value, or may be an engagement force profile that varies during the engagement cycle. In controlled joint force embodiments, feedback control of joint force may be constant, ramped, or proportional based on one or more inputs (eg, ultrasonic amplitude, time, velocity, deformation, temperature, etc.).

As described herein, one or more of the semiconductor elements may be heated prior to and/or during the bonding cycle. Exemplary temperature ranges for semiconductor components are between 20°C and 250°C. Heat (eg, applied by one or both of the bonding tool and support structure, or other elements) may be applied as a constant value, or may be a temperature profile that varies during the bonding cycle, and may be controlled using feedback control.

Although the present invention is primarily described and illustrated in relation to the formation of ultrasonic joints between aluminum conductive structures on corresponding semiconductor components, the present invention is of course not limited thereto. That is, the teachings of the present invention may be adapted to form ultrasonic joints between conductive structures having different compositions. An exemplary list of materials for the conductive structures being connected includes: Aluminum and Copper (i.e., to form an ultrasonic bond between an aluminum conductive structure on one semiconductor element and a copper conductive structure on another semiconductor element) ; lead-free solder (eg, consisting essentially of tin) and copper; lead-free solder and aluminum; copper and copper; aluminum and silver; copper and silver; aluminum and gold; gold and gold; and copper and gold. Of course, other combinations of conductive structural components (eg, indium) are conceivable.

As provided above, although aspects of the present invention have been described in connection with aluminum materials included in various conductive structures of semiconductor elements, the present invention is not limited thereto. That is, the conductive structures on the semiconductor element may include (or be formed from) various materials. For example, conductive structures on the upper semiconductor element (e.g., the element carried and bonded using a bonding tool) and/or on the lower semiconductor element (e.g., the element to which the upper conductive element is bonded) may be formed from copper ( or include copper). Such copper material surfaces may be subject to atmospheric contamination; that is, the copper surface tends to oxidize.

Therefore, in some embodiments of the present invention, at least one conductive structure of the plurality of first conductive structures and the plurality of second conductive structures may be formed of (or include) copper. In such an embodiment of the invention, the entire conductive structure need not be formed of copper, instead, the plurality of first conductive structures and/or the plurality of second conductive structures may be adjacent to the plurality of first conductive structures and the plurality of second conductive structures. The interface portion of the other conductive structure of the two conductive structures includes copper.

According to aspects of the invention, coatings (e.g., inorganic coatings) may be applied to the surface of such conductive structures prior to ultrasonic bonding to prevent the joining of copper surfaces (e.g., copper conductive structures such as copper pillars). surface) oxidation. In particular, such coatings may be applied to conductive structures on upper semiconductor elements (e.g., elements carried and bonded using a bonding tool) and/or to conductive structures on lower semiconductor elements (e.g., upper conductive components) prior to bonding. A component engages a surface (eg, a bonding surface) of a conductive structure on the component to which it is bonded.

For example, such a coating may be an inorganic coating (eg, a silicon oxynitride coating) applied as a thin, friable coating on a conductive structure (eg, a copper pillar conductive structure). The coating may serve to protect some of these conductive structures, such as copper conductive structures, from oxidation, etc. . Subsequently, in conjunction with an ultrasonic flip-chip bonding process, the coating(s) on the corresponding conductive structures are ultrasonically erased, thereby establishing metal-to-metal contacts/interconnections.

By providing a coating on the conductive structure, the productivity and robustness of fine-pitch flip-chip packaging can be improved. For example, as flip-chip packages (which may include copper interconnects) move toward finer and finer pitches, the use of coatings is suitable for applications including, but not limited to, die-to-substrate, die-to-die, and die-to-die Interconnects are formed in various occasions of the circle.

After ultrasonic energy is used to break through the coating (and/or other oxide layers formed on the conductive structures), the final connection process (for example, which may include heat, pressure, etc.) between the conductive structures of the semiconductor element is completed. and/or any desired combination of forces).

8A to 8C (together with the flowchart of FIG. 9 ), FIGS. 10A to 10C (together with the flowchart of FIG. 11 ), and FIGS. 12A to 12C (together with the flowchart of FIG. 13 ) show A system and method for forming interconnections between coated semiconductor elements. 9 , 11 and 13 show flowcharts of a method of bonding semiconductor elements together according to an exemplary embodiment of the present invention. As those skilled in the art will appreciate, certain steps included in the flowcharts may be omitted; some additional steps may be added; and the order of the steps may be changed relative to the order shown.

Referring specifically to FIG. 8A , upper semiconductor component 808 is held by holding portion 810 of bonding tool 824 (eg, by vacuum, such as by a vacuum port defined by a holding surface of holding portion 810 ). The upper semiconductor device 808 includes upper conductive structures 812a and 812b on the lower surface thereof. Lower semiconductor component 860 includes semiconductor die 802 bonded to (or otherwise supported by) substrate 804 . Lower conductive structures 806 a and 806 b (eg, copper conductive structures such as copper pillars, other conductive structures) are disposed on the upper surface of the lower semiconductor die 802 . Coating 806a1 is disposed on conductive structure 806a, and coating 806b1 is disposed on conductive structure 806b. Substrate 804 is in turn supported by support structure 850 (eg, a heat block of machine 800, an anvil of machine 800, or any other desired support structure). In the structure shown in FIG. 8A (ready for bonding), each of the upper conductive structures 812a and 812b are generally aligned with the corresponding lower conductive structures 806a and 806b. The semiconductor element 808 is moved downwardly by movement of the bonding tool 824 (shown by arrow 826 in FIG. 8A ). After this movement, FIG. 8B shows contact between respective conductive structures 806a (including coating 806a1 ) and 812a and 806b (including coating 806b1 ) and 812b. Ultrasonic energy 814 is applied through bonding tool 824 to the upper semiconductor element 808 and the upper conductive Structures 812a and 812b. For example, the ultrasonic transducer carrying the bonding tool 824 may in turn be carried by the bond head assembly of the flip chip bonder 800 . During ultrasonic bonding, the lower conductive structures 806a and 806b may pass through the support provided by the support structure 850 to the lower semiconductor element 860 (for example, the support surface of the support structure 850 may include one or more vacuum ports to hold the substrate during bonding). 804 is secured to a support structure 850) to remain relatively stationary. Ultrasonic energy 814 (along with optional bonding force and/or heat) can locally deform the conductive structure. For example, in FIG. 8C, conductive structures 806a and 806b and 812a and 812b are shown deformed (or at least partially deformed). In FIG. 8C , an ultrasonic bond is formed between corresponding pairs of conductive structures. For example, ultrasonic bond 828a is formed between deformed conductive structures 812a'/806a', and ultrasonic bond 828b is formed between deformed conductive structures 812b'/806b'.

Referring specifically to FIG. 9, in step 900, a first semiconductor component (eg, comprising a semiconductor die on a substrate, such as component 860 shown in FIG. 8A) is supported on a support structure of a bonding machine. A first semiconductor element (e.g., an upper surface of a semiconductor structure) includes a plurality of first conductive structures including a contact surface (e.g., a bonding surface for flip-chip bonding) of the conductive structures. Fragile coatings (see, eg, structures 806a and 806b including coatings 806a1 and 806b1 of element 860 as shown in FIG. 8A ). In step 902, a second semiconductor component is held by a holding portion of a bonding tool of a bonding machine (see, eg, component 808 in FIG. 8A). The second semiconductor element includes a plurality of second conductive structures (eg, on a lower surface of the second semiconductor element). In step 904, the first conductive structure and the second conductive structure are aligned with each other (see, eg, FIG. 8A), and then brought into contact with each other (see, eg, FIG. 8B). In step 906, ultrasonic energy (such as in FIG. 8B through a bonding tool carrying the second semiconductor element) is applied to the second semiconductor element such that the conductive structure of the second semiconductor element disrupts the conductive structure of the first semiconductor element. Corresponding coatings are associated with ultrasonic bonds formed between the pair of conductive structures (see, eg, ultrasonic bonds 828a and 828b in FIG. 8C ).

Referring specifically to FIG. 10A , upper semiconductor element 1008 is held by holding portion 1010 of bonding tool 1024 (eg, by vacuum, such as by a vacuum port defined by a holding surface of holding portion 1010 ). Upper semiconductor element 1008 includes upper conductive structures 1012a and 1012b (eg, formed of or comprising copper) on a lower surface thereof, wherein coating 1012a1 is disposed on conductive structure 1012a and coating 1012b1 is disposed on on the conductive structure 1012b. Lower semiconductor element 1060 includes semiconductor die 1002 bonded to (or otherwise supported by) substrate 1004 . Lower conductive structures 1006 a and 1006 b (eg, copper conductive structures such as copper pillars, other conductive structures) are disposed on the upper surface of the lower semiconductor die 1002 . The substrate 1004 is in turn supported by a support structure 1050 (eg, a heat block of the machine 1000, an anvil of the machine 1000, or any other desired support structure). In the structure shown in FIG. 10A (ready for bonding), each of the upper conductive structures 1012a and 1012b is generally aligned with the corresponding lower conductive structures 1006a and 1006b. The semiconductor element 1008 is moved downward by movement of the bonding tool 1024 (shown by arrow 1026 in FIG. 10A ). After this movement, FIG. 10B shows contact between respective conductive structures 1006a and 1012a (including coating 1012a1 ) and 1006b and 1012b (including coating 1012b1 ). Ultrasonic energy 1014 is applied to the upper semiconductor element 1008 and the upper conductive structures 1012a and 1012b through the bonding tool 1024 using an ultrasonic transducer. For example, an ultrasonic transducer carrying bonding tool 1024 may in turn be carried by a bonding head element of machine 1000 . During ultrasonic bonding, the lower conductive structures 1006a and 1006b may pass through the support provided by the support structure 1050 to the lower semiconductor element 1060 (for example, the support surface of the support structure 1050 may include one or more vacuum ports to hold the substrate during bonding. 1004 is secured to a support structure 1050) to remain relatively stationary. Ultrasonic energy 1014 (along with optional bonding force and/or heat) may locally deform the conductive structure. For example, in FIG. 1OC, conductive structures 1006a and 1006b and 1012a and 1012b are shown deformed (or at least partially deformed). In FIG. 10C , an ultrasonic bond is formed between corresponding pairs of conductive structures. For example, ultrasonic bond 1028a is formed between deformed 1012a'/1006a', and ultrasonic bond 1028b is formed between deformed conductive structures 1012b'/1006b'.

Referring specifically to FIG. 11 , in step 1100 a first semiconductor component (eg, comprising a semiconductor die on a substrate, such as component 1060 shown in FIG. 10A ) is supported on a support structure of a bonding machine. The first semiconductor element (eg, the upper surface of the semiconductor structure) includes a plurality of first conductive structures (see, eg, structures 1006a and 1006b of element 1060 shown in FIG. 10A ). In step 1102, a second semiconductor component is held by a holding portion of a bonding tool of a bonding machine (see, eg, component 1008 in FIG. 10A). The second semiconductor element includes a plurality of second conductive structures (e.g., on the lower surface of the second semiconductor element) including coatings on contact portions of the conductive structures (see, e.g., FIG. 10A ). As shown, structure 1012a and 1012b) of element 1060 including coatings 1012a1 and 1012b1. In step 1104, the first conductive structure and the second conductive structure are aligned with each other (see, eg, FIG. 10A), and then brought into contact with each other. In step 1106, ultrasonic energy (such as in FIG. 10B through a bonding tool carrying the second semiconductor element) is applied to the second semiconductor element such that the conductive structure of the first semiconductor element destroys the conductive structure of the second semiconductor element. Corresponding coatings are associated with forming an ultrasonic bond between the pair of conductive structures (see, eg, ultrasonic bonds 1028a and 1028b in FIG. 1OC).

Referring specifically to FIG. 12A , upper semiconductor element 1208 is held by holding portion 1210 of bonding tool 1224 (eg, by a vacuum, such as by a vacuum port defined by a holding surface of holding portion 1210 ). Upper semiconductor element 1208 includes upper conductive structures 1212a and 1212b (eg, formed of or comprising copper) on a lower surface thereof, wherein coating 1212a1 is disposed on conductive structure 1212a and coating 1212b1 is disposed on on the conductive structure 1212b. Lower semiconductor element 1260 includes semiconductor die 1202 bonded to (or otherwise supported by) substrate 1204 . Lower conductive structures 1206 a and 1206 b (eg, copper conductive structures such as copper pillars, other conductive structures) are disposed on the upper surface of lower semiconductor die 1202 . Coating 1206a1 is disposed on conductive structure 1206a, and coating 1206b1 is disposed on conductive structure 1206b. The substrate 1204 is in turn supported by a support structure 1250 (eg, a heat block of the machine 1200, an anvil of the machine 1200, or any other desired support structure). In the structure shown in FIG. 12A (ready for bonding), each of the upper conductive structures 1212a and 1212b is generally aligned with the corresponding lower conductive structures 1206a and 1206b. Semiconductor element 1208 is moved downwardly by movement of bonding tool 1224 (shown by arrow 1226 in FIG. 12A ). After this movement, FIG. 12B shows contact between respective conductive structures 1206a (including coating 1206a1 ) and 1212a (including coating 1212a1 ) and 1206b (including coating 1206b1 ) and 1212b (including coating 1212b1 ). Ultrasonic energy 1214 is applied through bonding tool 1224 to upper semiconductor element 1208 and upper conductive structure 1212a and 1212b. For example, an ultrasonic transducer carrying bonding tool 1224 may in turn be carried by a bonding head element of machine 1200 . During ultrasonic bonding, the lower conductive structures 1206a and 1206b may pass through the support provided by the support structure 1250 to the lower semiconductor element 1260 (for example, the support surface of the support structure 1250 may include one or more vacuum ports to hold the substrate during bonding. 1204 is secured to a support structure 1250) to remain relatively stationary. Ultrasonic energy 1214 (along with optional bonding force and/or heat) may locally deform the conductive structure. For example, in Figure 12C, conductive structures 1206a and 1206b and 1212a and 1212b are shown deformed (or at least partially deformed). In FIG. 12C , an ultrasonic bond is formed between corresponding pairs of conductive structures. For example, ultrasonic bond 1228a is formed between deformed conductive structures 1212a'/1206a', and ultrasonic bond 1228b is formed between deformed conductive structures 1212b'/1206b'.

Referring specifically to FIG. 13, in step 1300, a first semiconductor component (eg, comprising a semiconductor die on a substrate, such as component 1260 shown in FIG. 12A) is supported on a support structure of a bonding machine. A first semiconductor element (e.g., an upper surface of a semiconductor structure) includes a plurality of first conductive structures including a coating on a contact surface of the conductive structures (see, e.g., shown in FIG. 12A , element 1260 structure 1206a and 1206b) including coatings 1206a1 and 1206b1. In step 1302, a second semiconductor component is held by a holding portion of a bonding tool of a bonding machine (see, eg, component 1208 in FIG. 12A). The second semiconductor element includes a plurality of second conductive structures (e.g., on the lower surface of the second semiconductor element) including coatings on contact portions of the conductive structures (see, e.g., shown in FIG. 12A ). , structures 1212a and 1212b of element 1208 including coatings 1212a1 and 1212b1 ). In step 1304, the first conductive structure and the second conductive structure are aligned with each other (see, eg, FIG. 12A), and then brought into contact with each other. In step 1306, ultrasonic energy (such as in FIG. 12B through a bonding tool carrying the second semiconductor element) is applied to the second semiconductor element such that the conductive structure of the second semiconductor element disrupts the conductive structure of the first semiconductor element. Corresponding coatings associated with forming an ultrasonic bond (see, for example, ultrasonic bonds 1228a and 1228b in FIG. 12C ) between the pair of conductive structures (and vice versa, i.e., the conductive structures of the first semiconductor element destroying the corresponding coating of the conductive structure of the second semiconductor element in connection with the formation of the ultrasonic joint between the pair of conductive structures).

Corresponding pairs of conductive elements (806a and 812a and 806b and 812b in FIG. 8A; 1006a and 1012a and 1006b and 1012b in FIG. 10A; and 1206a and 1212a and 1206b and 1212b in FIG. without adding heat during the bonding process) are bonded together. Optionally, heat may be applied to the upper semiconductor elements 808/1008/1012 by bonding tools 824/1024/1224 during the bonding process, thereby heating the corresponding upper conductive elements, for example; and/or (2) During the bonding process, heat is applied to the lower semiconductor element 860/1060/1260 through the support structure 850/1050/1250, thereby heating the corresponding lower conductive structure. Such optional heating (eg, by bonding tools and/or support structures, etc.) is applicable to any embodiment of the invention shown and described herein.

In addition, during a bonding process (eg, the processes shown and described in conjunction with FIGS. 8A to 8C , 10A to 10C , and 12A to 12C ), the plurality of first conductive structures and The second conductive structures are pressed together. The predetermined magnitude of bonding force may be a single bonding force value, or may be a bonding force profile in which actual bonding force varies during the flip chip bonding operation.

Regardless of the particular elements described above, semiconductor elements 860 and 808 (in FIGS. 8A-8C ), 1060 and 1008 (in FIGS. 10A-10C ), and 1260 and 1208 (in FIGS. 12A-12C ) may be configured Any one of a plurality of semiconductor elements that are bonded together (for example, a memory device configured to be bonded to a processor). For example, the lower semiconductor element (860, 1060, 1260) may be a semiconductor die, wafer, panel, substrate, and many other possibilities configured to receive the upper semiconductor element (e.g., die) during a flip chip bonding process. components.

Conductive structures (i.e., 812a, 812b, 806a, and 806b in FIGS. 8A-8C; 1012a, 1012b, 1006a, and 1006b in FIGS. ) are shown as generic constructs. These structures can take many different forms, such as conductive posts, stud bumps (for example, formed using a stud bump machine), plated conductive structures, sputtered conductive structures, wire sections, bond pads, contact pads, and other forms. Various other figures provided herein show specific examples of such structures. According to some embodiments of the present invention, the conductive structure may be formed of or include copper or some other material that is oxidized, or the like.

Although the invention has been illustrated and described with reference to particular embodiments, the invention is not intended to be limited to the details of the description. Rather, various modifications may be made to the details of the invention within the scope and range of equivalents of the claims and without departing from the invention.

100‧‧‧ultrasonic bonding machine, machine 102‧‧‧semiconductor grain, lower semiconductor grain 104‧‧‧substrate 106a, 106b‧‧‧conductive structure, lower conductive structure, conductive element, structure 106a'‧‧‧conduction Structure 108‧‧‧semiconductor element, upper semiconductor element, element 110‧‧‧holding part 112a, 112b‧‧‧conductive structure, upper conductive structure, conductive element, upper conductive element 112a'‧‧‧conductive structure 114‧‧‧super Sonic energy 124‧‧‧bonding tool 126‧‧‧arrow 128a, 128b‧‧‧ultrasonic bonding part 150‧‧‧supporting structure 160‧‧‧semiconductor element, lower semiconductor element, element 200‧‧‧ultrasonic bonding machine 202 ‧‧‧semiconductor die, lower semiconductor die 204‧‧‧substrate 206a, 206b‧‧‧lower conductive structure, conductive structure, structure 208‧‧‧upper semiconductor element, element 210‧‧‧holding part 216‧‧‧upper Aluminum contact structure, aluminum contact structure/part 216'‧‧‧contact structure 222a, 222b‧‧‧upper conductive structure, conductive aluminum pad 222a'‧‧‧upper conductive structure 224‧‧‧bonding tool 228‧‧‧ultrasonic Bonding part 230‧‧‧copper pillar, Cu pillar 250‧‧‧support structure 260‧‧‧lower semiconductor element, element 300‧‧‧ultrasonic bonding machine 302‧‧‧semiconductor die, die 304‧‧‧substrate 306a , 306b‧‧‧lower conductive structure, conductive structure, structure 308‧‧‧upper semiconductor element 310‧‧‧holding part 316a, 316b‧‧‧upper aluminum contact structure, aluminum contact structure 320a, 320b‧‧‧wire ring 322a, 322b‧‧‧Upper conductive structure, conductive aluminum pad, conductive structure, aluminum conductive structure 324‧‧‧bonding tool 330a, 330b‧‧‧Cu pillar 334‧‧‧coating/packaging 350‧‧‧supporting structure 360‧‧ ‧Package semiconductor device, lower semiconductor element, component 400 , structure 406a, 406a'‧‧‧structure 408‧‧‧upper semiconductor element, semiconductor element, element 410‧‧‧holding part 412a, 412b‧‧‧upper conductive structure, conductive structure 412a, 412a'‧‧‧structure 414‧ ‧‧ultrasonic energy 424‧‧‧bonding tools 428a, 428b‧‧‧ultrasonic bonding part 428a'‧‧‧complete ultrasonic bonding part 450‧‧‧supporting structure 460‧‧‧lower semiconductor components, components 500‧‧‧ Ultrasonic bonding machine 502‧‧‧semiconductor die, lower semiconductor die 504‧‧‧substrate 506a, 506b‧‧‧lower conductive structure, structure 506a, 506a'‧ ‧‧structure 508‧‧‧semiconductor element, upper semiconductor element, element 510‧‧‧holding part 522a, 522b‧‧‧upper conductive structure, conductive aluminum pad 522a, 522a'‧‧‧structure 524‧‧‧bonding tool 528a , 528b‧‧‧ultrasonic bonding part 528a'‧‧‧complete ultrasonic bonding part 550‧‧‧supporting structure 560‧‧‧lower semiconductor components, components 600‧‧‧ultrasonic bonding machines 602a, 602b, 602c, 602d‧ ‧‧Semiconductor grains 604a, 604b, 604c, 604d‧‧‧Substrate, upper semiconductor element 606a, 606b, 612a, 612b‧‧‧conductive structure, aluminum conductive structure 606a', 606b', 612a', 612b'‧‧‧ Conductive structure, aluminum conductive structure 606a'', 606b'', 612a'', 612b''‧‧‧conductive structure, structure 624‧‧‧bonding tool 628a, 628b‧‧‧ultrasonic bonding part 628a', 628b'‧ ‧‧Ultrasonic bonding part 650‧‧‧supporting structure 660a, 660b, 660c, 660d‧‧‧semiconductor components, components 700, 702, 704, 706, 708, 710‧‧‧step 800‧‧‧flip chip bonding machine , machine 802‧‧‧lower semiconductor grain, semiconductor grain 804‧‧‧substrate 806a, 806b‧‧‧conductive structure, lower conductive structure, structure, conductive element 806a', 806b'‧‧‧conductive structure 806a1, 806b1‧ ‧‧coating 808‧‧‧upper semiconductor element, component, semiconductor element 810‧‧‧holding part 812a, 812b‧‧‧upper conductive structure, conductive structure, conductive element 812a', 812b'‧‧‧conductive structure 814‧‧ ‧Ultrasonic energy 824‧‧‧bonding tool 826‧‧‧arrows 828a, 828b‧‧‧ultrasonic bonding part 850‧‧‧supporting structure 860‧‧‧lower semiconductor components, components, semiconductor components 900, 902, 904, 906 ‧‧‧step 1000‧‧‧machine 1002‧‧‧semiconductor die, lower semiconductor die 1004‧‧‧substrate 1006a, 1006b‧‧‧lower conductive structure, conductive structure, structure, conductive element 1006a', 1006b'‧‧ ‧Conductive structure 1008‧‧‧upper semiconductor element, semiconductor element, element 1010‧‧‧holding part 1012‧‧‧upper semiconductor element 1012a, 1012b‧‧‧upper conductive structure, conductive structure, conductive element 1012a', 1012b'‧‧ ‧Conductive structure 1012a1, 1012b1 ‧‧‧coating 1014‧‧‧ultrasonic energy 1024‧‧‧bonding tool 1026‧‧‧arrow 1028a, 1028b‧‧‧ultrasonic joint 1050‧‧‧supporting structure 1060‧‧‧down Part semiconductor element, element, semiconductor element 1100, 1102, 1104, 1106‧‧‧step 1200‧‧‧machine 1202‧‧‧semiconductor die, lower semiconductor die 1204‧‧‧substrate 1206a, 1206b‧‧‧lower conductive structure , conductive structure, structure, conductive element 1206a', 1206b'‧‧‧conductive structure 1206a1, 1206b1 coating 1208‧‧‧upper semiconductor element, semiconductor element 1210‧‧‧holding part 1212a, 1212b‧‧‧upper conductive structure, conductive Structure, conductive element 1212a', 1212b'‧‧‧conductive structure 1212a1, 1212b1‧‧‧coating 1214‧‧‧ultrasonic energy 1224‧‧‧bonding tool 1226‧‧‧arrow 1228a, 1228b‧‧‧ultrasonic joint 1250‧‧‧supporting structure 1260‧‧‧lower semiconductor components, components, semiconductor components 1300, 1302, 1304, 1306‧‧‧steps

The present invention is best understood from the following detailed description when read with the accompanying drawings. It is emphasized that, according to common practice, the various features of the drawings are not drawn to scale. On the contrary, the dimensions of the various features are arbitrarily expanded or reduced for clarity. The accompanying drawings include the following drawings: FIGS. 1A to 1C are partial block diagrams of an ultrasonic bonding machine, showing a structure and a method for bonding an upper semiconductor element to a lower semiconductor element according to an exemplary embodiment of the present invention; FIG. 2A is a block diagram of a part of an ultrasonic bonding machine, showing a structure and a method for bonding an upper semiconductor element to a lower semiconductor element according to another exemplary embodiment of the present invention; Enlarged view; FIG. 2C is a schematic diagram of FIG. 2B after ultrasonic bonding; FIG. 3 is a block diagram of a part of an ultrasonic bonding machine, showing an upper semiconductor element bonded to a lower semiconductor element according to another exemplary embodiment of the present invention structure and method; FIG. 4A is a partial block diagram of an ultrasonic bonding machine, showing a structure and a method for bonding an upper semiconductor element to a lower semiconductor element according to yet another exemplary embodiment of the present invention; FIG. 4B is a block diagram of FIG. 4A "Fig. 4B" part of the enlarged view; Fig. 4C is a schematic diagram of Fig. 4B after ultrasonic bonding; Fig. 5A is a block diagram of part of the ultrasonic bonding machine, showing the upper semiconductor according to another exemplary embodiment of the present invention The structure and method of component bonding to the lower semiconductor component; FIG. 5B is an enlarged view of the “FIG. 5B” portion of FIG. 5A; FIG. 5C is a schematic diagram of FIG. 5B after ultrasonic bonding; FIG. 6A is a block of a part of an ultrasonic bonding machine 6B is an enlarged view of the "Fig. 6B" part of Fig. 6A; Fig. 6C is a part of Fig. 6A A schematic diagram after contact between conductive structures; FIG. 7 shows a flow chart of a method for ultrasonic bonding of a semiconductor element according to an exemplary embodiment of the present invention; FIGS. 8A to 8C are blocks of parts of an ultrasonic bonding machine Fig. 9 shows a structure and a method for bonding an upper semiconductor element to a lower semiconductor element according to an exemplary embodiment of the present invention; Flowchart; FIG. 10A to FIG. 10C are partial block diagrams of an ultrasonic bonding machine, showing another structure and method of bonding an upper semiconductor element to a lower semiconductor element according to another exemplary embodiment of the present invention; FIG. 11 shows A flow chart of yet another method for ultrasonically bonding a semiconductor element according to yet another exemplary embodiment of the present invention; FIGS. 12A to 12C are block diagrams of parts of an ultrasonic bonding machine, showing yet another example according to the present invention Still another structure and method of bonding an upper semiconductor element to a lower semiconductor element according to an exemplary embodiment; and FIG. 13 shows a flow chart of yet another method of ultrasonically bonding a semiconductor element according to yet another exemplary embodiment of the present invention.

800‧‧‧Flip chip bonder, machine

802‧‧‧lower semiconductor die

804‧‧‧substrate

806a, 806b‧‧‧conductive structure, lower conductive structure, structure, conductive element

806a1, 806b1‧‧‧coating

808‧‧‧Upper semiconductor components, components, semiconductor components

810‧‧‧maintenance part

812a, 812b‧‧‧Upper conductive structure, conductive structure, conductive element

824‧‧‧joining tools

826‧‧‧arrow

850‧‧‧Supporting structure

860‧‧‧Lower semiconductor components, components, semiconductor components

Claims (25)

A method for ultrasonically bonding a semiconductor element, the method comprising the following steps: (a) combining the surfaces of a plurality of first conductive structures of a first semiconductor element with surfaces of a plurality of second conductive structures of a second semiconductor element corresponding surface alignment, wherein the bonding surface of at least one of the first conductive structures and the second conductive structures includes a friable coating; and (b) aligning the plurality of first conductive structures A conductive structure is ultrasonically bonded to corresponding ones of the second conductive structures, wherein, in step (b), the brittle coating is ultrasonically erased. According to the method described in claim 1, wherein the first semiconductor element is a semiconductor crystal grain. According to the method described in claim 1, each of the first semiconductor element and the second semiconductor element is a corresponding semiconductor crystal grain. According to the method described in claim 1, wherein the first semiconductor element includes a semiconductor crystal grain. The method according to claim 1, wherein each of the first semiconductor device and the second semiconductor device includes a corresponding semiconductor die. According to the method described in item 1 of the patent scope of the application, it further includes the following steps: moving the first semiconductor element towards the second semiconductor element, so that the plurality of lower surfaces of the first conductive structures correspond to the corresponding The plurality of upper surfaces of the second conductive structure are in contact. The method according to claim 1, further comprising the step of applying pressure between the first semiconductor element and the second semiconductor element during at least a portion of the step (b). According to the method described in claim 1, further comprising the step of deforming a plurality of first conductive structures among the first conductive structures during the step (b). According to the method described in item 1 of the scope of application, wherein, the step (b) is carried out at ambient temperature. The method according to claim 1, further comprising the step of: heating at least one of the first semiconductor element and the second conductive element during at least a portion of the step (b). The method according to claim 1, further comprising the step of heating the first semiconductor element during at least a portion of the step (b) using a bonding tool holding the first semiconductor element. According to the method described in claim 1, further comprising the step of: during at least a part of the step (b), using a support structure that supports the second semiconductor element during the step (b) to support the second semiconductor element The second semiconductor element is heated. According to the method described in claim 1, at least one of the first conductive structures and the second conductive structures is formed of copper. According to the method described in claim 1, each of the first conductive structures and the second conductive structures is a copper conductive structure. According to the method described in claim 1, wherein at least one of the first conductive structures and the second conductive structures is adjacent to the other of the first conductive structures and the second conductive structures An interface portion of the includes copper. The method according to claim 1, wherein the step (b) includes using a bonding tool that holds the first semiconductor element during the step (b) to bond a plurality of the first conductive structures to The first conductive structure is ultrasonically bonded to a plurality of corresponding second conductive structures among the second conductive structures. According to the method of claim 16, during the step (b), the engaging tool is engaged with an ultrasonic transducer to provide ultrasonic energy. The method according to claim 16, wherein the bonding tool utilizes a vacuum to hold the first semiconductor element during the step (b). According to the method described in claim 1, wherein the brittle coating is a ceramic coating. According to the method described in item 1 of the patent claims, wherein, the brittle coating is a surface layer composed of silicon nitride, oxide or carbide or their mixtures. According to the method described in claim 1, the thickness of the brittle coating is between 10 angstroms and 500 angstroms. According to the method described in claim 1, wherein the thickness of the fragile coating is between 15 angstroms and 250 angstroms. A method for ultrasonically bonding a semiconductor element, the method comprising the following steps: (a) combining a plurality of surfaces of a plurality of first conductive structures of a first semiconductor element with a plurality of second conductive structures of a second semiconductor element A plurality of corresponding surfaces are aligned, the first semiconductor element is supported by a support structure of a bonding machine, and the second semiconductor element is carried by a bonding tool of the bonding machine, wherein a bonding surface of the first conductive structures includes a friable coating; and (b) ultrasonically bonding a plurality of first ones of the first conductive structures to a corresponding second ones of the second conductive structures using the bonding tool, Wherein, in step (b), the brittle coating is erased by ultrasonic waves. A method for ultrasonically bonding a semiconductor element, the method comprising the following steps: (a) combining a plurality of surfaces of a plurality of first conductive structures of a first semiconductor element with a plurality of second conductive structures of a second semiconductor element A plurality of corresponding surfaces are aligned, the first semiconductor element is supported by a support structure of a bonding machine, and the second semiconductor element is carried by a bonding tool of the bonding machine, wherein a bonding surface of the second conductive structures includes a friable coating; and (b) ultrasonically bonding a plurality of first ones of the first conductive structures to a corresponding second ones of the second conductive structures using the bonding tool, Wherein, in step (b), the brittle coating is erased by ultrasonic waves. A method for ultrasonically bonding a semiconductor element, the method comprising the following steps: (a) combining a plurality of surfaces of a plurality of first conductive structures of a first semiconductor element with a plurality of second conductive structures of a second semiconductor element A plurality of corresponding surfaces of the structure are aligned, the first semiconductor element is supported by a support structure of a bonding machine, and the second semiconductor element is carried by a bonding tool of the bonding machine, wherein the first conductive structures and the second The bonding surface of each of the two conductive structures includes a frangible coating; and (b) ultrasonically bonding a plurality of the first conductive structures into the second conductive structure using the bonding tool A corresponding plurality of second conductive structures, wherein, in step (b), the brittle coating is ultrasonically erased.

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