KR102475581B1 - Systems and methods for bonding semiconductor elements - Google Patents

Abstract

A method of ultrasonic bonding of semiconductor elements includes: (a) aligning each surface of a plurality of first conductive structures of a first semiconductor element with each surface of a plurality of second conductive structures of a second semiconductor element; and (b) ultrasonically bonding each of the first conductive structures to each of the second conductive structures. At least one bonding surface of the first conductive structure and the second conductive structure includes a frangible coating.

Description

Semiconductor element bonding system and method {SYSTEMS AND METHODS FOR BONDING SEMICONDUCTOR ELEMENTS}

CROSS REFERENCES OF RELATED APPLICATIONS

This application is a partial continuation of Application No. 15/147,015 filed on May 5, 2016, and the application is a divisional application of Application No. 14/822,164 filed on August 10, 2015, and this divisional application is filed in 2014 Application Serial No. 14/505,609, filed on October 3, 2013 (now US Patent 9,136,240), which claims the benefit of Provisional Application No. 61/888,203, filed on October 8, 2013, the content of each application are incorporated herein by reference.

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

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

Although advanced packaging technologies are increasingly being used, there are many limitations to these technologies, including, for example, limitations associated with the relative immaturity of certain advanced packaging technologies. Thus, it would be desirable to provide an improved system and method for bonding semiconductor elements together.

According to one exemplary embodiment of the present invention, a semiconductor element ultrasonic bonding method for ultrasonically bonding semiconductor elements is provided. The method includes (a) aligning a surface of a plurality of first conductive structures of a first semiconductor element with a respective surface of a plurality of second conductive structures of a second semiconductor element; and (b) ultrasonically bonding the first conductive structure to each of the second conductive structures. Prior to step (b), the bonding surface of at least one of the first conductive structure and the second conductive structure includes a frangible coating.

For example, to protect a bonding surface of the conductive structure from oxidation (eg, where the conductive structure is formed of or may include copper), a conductive structure of at least one of the first semiconductor element and the second semiconductor element is attached to a fragile conductive structure. A coating may be applied prior to flip chip bonding. This coating may be a surface layer of a nitride, oxide or oxide of silicon or a mixture thereof, suitable for bonding without flux treatment and also obtaining metal-to-metal contact between the conductive structures of the first semiconductor element and the second semiconductor element. have a sufficiently brittle thickness under ultrasonic bonding for An exemplary range of thickness of the coating is from 10 Angstroms to 500 Angstroms, and another exemplary range is from 15 Angstroms to 250 Angstroms. The coating may be a nitride, oxide or carbide of Ti, Ta, In, Al, Sn, Zn, Zr, V, Cr, Ni, for example.

A sufficiently fragile ceramic coating may be used to obtain metal-to-metal contact between the bonding surfaces of each conductive structure during ultrasonic flip chip bonding and to obtain a surface suitable for bonding without fluxing.

That is, there is provided a method for protecting from contaminants (eg, copper oxide) or removing contaminants from bonding surfaces of conductive structures (eg, copper conductive structures) for flip chip bonding including ultrasonic bonding. This method coats the bonding surfaces with a layer of ceramic material having a thickness that is suitable for bonding without solvent treatment and provides the layer with sufficient brittle hardness during flip chip to obtain metal-to-metal contact between the bonding surfaces of the conductive structures. includes doing

The coating of the conductive structure may be a surface layer coating of a rare earth metal forming a composite with copper (eg, when the conductive structure comprising the coating is copper). The coating is a layer of ceramic hydride (eg, copper-) having a thickness suitable for bonding without solvent treatment upon formation of a copper composite (and when exposed to a reducing environment containing, for example, hydrogen) and providing the layer with the above-mentioned hardness. a layer of a metal hydride compound selected from metal hydrides of rare earth metal composites and metal hydrides of copper immiscible metals forming metal hydrides).

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is best understood from the following detailed description taken in conjunction with the accompanying drawings. In accordance with common practice, it is emphasized that the various elements of the drawings are not to scale. Conversely, the dimensions of various elements have been arbitrarily enlarged or reduced for clarity. The drawings include the following figures.

1A-1C are block diagrams of a portion of an ultrasonic bonding machine illustrating a structure and method for bonding an upper semiconductor element to a lower semiconductor element in accordance with one exemplary embodiment of the present invention.
2A is a block diagram of a portion of an ultrasonic bonding machine illustrating a structure and method for bonding an upper semiconductor element to a lower semiconductor element in accordance with another exemplary embodiment of the present invention.
FIG. 2B is an enlarged view of “FIG. 2B” in FIG. 2A.
Figure 2c is a view of Figure 2b after ultrasonic bonding.
3 is a block diagram of a portion of an ultrasonic bonding machine illustrating a structure and method for bonding an upper semiconductor element to a lower semiconductor element in accordance with another exemplary embodiment of the present invention.
4A is a block diagram of a portion of an ultrasonic bonding machine illustrating a structure and method for bonding an upper semiconductor element to a lower semiconductor element in accordance with another exemplary embodiment of the present invention.
FIG. 4B is an enlarged view of “FIG. 4B” in FIG. 4A.
4C is a view of FIG. 4B after ultrasonic bonding.
5A is a block diagram of a portion of an ultrasonic bonding machine illustrating a structure and method for bonding an upper semiconductor element to a lower semiconductor element in accordance with another exemplary embodiment of the present invention.
FIG. 5B is an enlarged view of “FIG. 5B” in FIG. 5A.
5C is a view of FIG. 5B after ultrasonic bonding.
6A is a block diagram of a portion of an ultrasonic bonding machine illustrating a structure and method for bonding an upper semiconductor element to a lower semiconductor element in accordance with another exemplary embodiment of the present invention.
FIG. 6B is an enlarged view of “FIG. 6B” in FIG. 6A.
Figure 6c shows a portion of Figure 6a after contact between the conductive structures.
7 is a flow chart illustrating a method of ultrasonically bonding semiconductor elements according to one exemplary embodiment of the present invention.
8A-8C are block diagrams of a portion of an ultrasonic bonding machine illustrating structures and methods for bonding an upper semiconductor element to a lower semiconductor element in accordance with one exemplary embodiment of the present invention.
9 is a flowchart illustrating a method of ultrasonically bonding semiconductor elements according to an exemplary embodiment of the present invention.
10A-10C are block diagrams of portions of an ultrasonic bonding machine illustrating different structures and methods for bonding an upper semiconductor element to a lower semiconductor element in accordance with another exemplary embodiment of the present invention.
11 is a flow chart illustrating yet another method of ultrasonically bonding semiconductor elements according to yet another exemplary embodiment of the present invention.
12A-12C are block diagrams of a portion of an ultrasonic bonding machine illustrating another structure and method for bonding an upper semiconductor element to a lower semiconductor element in accordance with another exemplary embodiment of the present invention.
13 is a flow chart illustrating yet another method of ultrasonically bonding semiconductor elements according to yet another exemplary embodiment of the present invention.

As used herein, “semiconductor element” refers to any structure that contains (or at a later stage is configured to contain) a semiconductor chip or die. Exemplary semiconductor elements include, among others, a bare semiconductor die, a semiconductor die on a substrate (eg, a leadframe, a PCB, a carrier, etc.), a packaged semiconductor device, a flip chip semiconductor device, a die embedded in a substrate, a semiconductor die. It includes a laminate of Semiconductor elements may also include elements bonded to or otherwise configured to be included in a semiconductor package (spacers, substrates, etc. to be bonded in a stacked die configuration).

According to certain exemplary embodiments of the present invention, an inventive technique (and structure) for assembling a semiconductor device such as a package on package (ie, package on package (PoP)) is provided. For example, a plurality of semiconductor elements (which may be packages) may be arranged in a stacked configuration. Each element preferably comprises aluminum (or aluminum alloy, or partially aluminum) that is ultrasonically bonded together. These technologies include, for example, reduced density compared to other interconnect technologies (eg, solder-based PoP technologies); Unlike other interconnect technologies, no solder mass reflow is used; and that room temperature ultrasonic bonding is possible through the use of aluminum-aluminum interconnects in some applications.

1A shows a portion of an ultrasonic bonding machine 100 that includes a bonding tool 124 and a support structure 150 . As will be appreciated by those skilled in the art, a thermocompression bonding machine (e.g., machine 100, or any of the other machine embodiments described herein) includes many elements (not shown in the drawings here for simplicity). can do. Exemplary elements include, among other elements, an input element for providing an input workpiece to be bonded with, for example, a further semiconductor element; an output element for receiving a processed workpiece, which now comprises a further semiconductor element; a transmission element for moving the work piece; an imaging system for imaging and aligning workpieces; a bonding head assembly having a bonding tool; a motion system for moving the bonding head assembly; and a computer system including software for operating the machine.

Referring again to FIG. 1A , the upper semiconductor element 108 is held by the holding portion 110 of the bonding tool 124 (e.g., a vacuum applied through a vacuum port formed on the holding surface of the holding portion 110). by). Upper semiconductor element 108 includes upper semiconductor structures 112a and 112b at its lower surface. The lower semiconductor element 160 includes a semiconductor die 102 bonded to (or supported by) a substrate 104 . Lower conductive structures 106a and 106b are provided on the upper surface of the lower semiconductor die 102 . The substrate 104 is supported by a support structure 150 (eg, a thermal block of the machine 100, an anvil of the machine 100, or other desired support structure). In the configuration shown in FIG. 1A (bonding preparation), each of the upper conductive structures 112a and 112b is generally aligned with the respective lower conductive structure 106a and 106b facing each other. The semiconductor element 108 is moved downward through motion of the bonding tool 124 (as indicated by arrow 126 in FIG. 1A). Figure 1b shows the contact between each of the conductive structures 106a, 112a; 106b, 112b that occurs after this movement. Using an ultrasonic transducer (not shown, but labeled “USG” (ultrasonic generator) in the drawings), ultrasonic energy 114 is directed through bonding tool 124 to upper semiconductor element 108 and upper conductive structure ( 112a, 112b) is applied. For example, an ultrasonic transducer carrying bonding tool 124 may be carried in the bonding head assembly of machine 100 .

During ultrasonic bonding, the lower conductive structures 106a and 106b may be held relatively immobile through the support of the lower semiconductor element 160 by the support structure 150 (e.g., the support surface of the support structure 150). may include one or more vacuum ports to secure the substrate 104 to the support structure 150 during bonding. Ultrasonic energy 114 (with optional bonding force and/or heat) can cause partial deformation of the conductive structure. For example, in FIG. 1C, the conductive structures 106a, 106b; 112a, 112b are shown in a partially strained state. In FIG. 1C, ultrasonic bonding is formed between each pair of conductive structures. For example, an ultrasonic bonding portion 128a is formed between the deformed conductive structures 112a'/106a', and an ultrasonic bonding portion 128b is formed between the deformed conductive structures 112b'/106b'. The conductive structures 106a, 106b; 112a, 112b may be formed of aluminum or an aluminum alloy or may contain aluminum in their bonding surfaces or the like.

Each pair of conductive elements 106a, 112a; 106b, 112b can be bonded together at room temperature (without heat added during the bonding process). Optionally, additional heat may be applied to the upper semiconductor element 108, such as (1) via the bonding tool 124 during the bonding process to heat the upper conductive elements 112a, 112b and/or (2) support during the bonding process. Heat may be applied to the lower semiconductor element 160 via the structure 150 (eg, the thermal block 150) to heat the lower conductive structures 106a and 106b. Such selective heating (eg, via bonding tools and/or support structures, etc.) may be applied to any of the embodiments of the invention shown and described herein.

The semiconductor elements 160 and 108 shown in FIGS. 1A-1C can be any of a number of semiconductor elements configured to be bonded together. In one very specific example (which may also apply to other embodiments shown and described herein), semiconductor element 160 is a processor (eg, a mobile phone processor, also known as an application processor unit (APU)), and semiconductor element 108 may be a memory device configured to be coupled to the processor as shown in FIGS. 1A-1C.

The conductive structures shown in FIGS. 1A-1C (ie, 112a, 112b, 106a, 106b) are shown as generic structures. These structures include, among others, conductive pillar stud bumps (e.g., formed using a stud bumping machine), electroplated conductive structures, sputtered conductive structures, wire parts, bonding pads, contact pads, and the like. It can take many different forms. Various other figures provided herein show specific examples of such structures. According to certain embodiments of the present invention, a conductive structure includes aluminum in a contact area (ie bonding surface) where it is bonded to another conductive structure. In this embodiment, the conductive structure may be formed of aluminum or an aluminum alloy (eg, aluminum alloyed with copper, aluminum alloyed with silicon and copper, etc.). As another example, the conductive structure may include a base conductive material other than aluminum (eg, copper) and have aluminum (or an aluminum alloy) in the contact region. Throughout this application, when a conductive structure is referred to as "aluminum", the conductive structure may be aluminum, an aluminum alloy, or may include aluminum (or an aluminum alloy) in a contact region of such a conductive structure. .

2A shows a portion of an ultrasonic bonding machine 200 that includes a bonding tool 224 and a support structure 250 . The upper semiconductor element 208 is held by the holding portion 210 of the bonding tool 224 (eg, in a vacuum), and the upper conductive structures 222a and 222b provided on the lower surface (ie, the conductive aluminum pad ( 222a, 222b)). The lower semiconductor element 260 includes a semiconductor die 202 bonded to (or supported by) a substrate 204 . Lower conductive structures 206a and 206b are provided on the upper surface of the lower semiconductor die 202 . And the substrate 204 is supported by the support structure 250 . In the configuration shown in FIG. 2A, each of the upper conductive structures 222a and 222b is generally aligned with (and configured to be ultrasonically bonded to) each of the opposing lower conductive structures 206a and 206b. The lower conductive structure 206a includes copper (Cu) pillars 230 provided on the upper surface of the lower semiconductor die 202, and upper aluminum contact structures 216 on the upper surface of the Cu pillars 230. . The upper aluminum contact structure 216 may be electroplated or sputtered onto the upper surface of the lower copper pillar 230, for example. 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 element 208 through bonding tool 224 using an ultrasonic transducer (not shown). Ultrasonic energy can cause partial deformation of the conductive structure as shown in FIG. 2C. That is, an ultrasonic bond 228 is formed between the strained upper conductive structure 222a' and the strained contact structure 216' (as shown in FIG. 2C).

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

3 shows a portion of an ultrasonic bonding machine 300 that includes 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, in a vacuum), and the upper conductive structures 322a and 322b (ie, the conductive aluminum pads 322a and 322b) are held. include FIG. 3 illustrates bonding of the packaged semiconductor device 360 (ie, the lower semiconductor element 360 ) to the upper semiconductor element 308 . The lower semiconductor element 360 includes a semiconductor die 302 bonded to (or otherwise supported by) a substrate 304 . Lower conductive structures 306a and 306b are provided on the upper surface of the substrate 304 . And the substrate 304 is supported by the support structure 350 . Wire loops 320a and 320b are bonded between the semiconductor die 302 and the substrate 304 (not shown in FIG. 3, but the die 302 is coupled to the substrate (as opposed to or in addition to the wire loop interconnects) 304)). A coating/encapsulation 334 (eg, epoxy molding compound) is applied over the die 302 and wire loops 320a, 320b. As shown, upper portions of the lower conductive structures 306a and 306b are exposed above the coating/capsule 334 to allow electrical connection with the upper semiconductor element 308 .

In the configuration shown in FIG. 3, each of the upper conductive structures 322a and 322b is generally aligned with (and configured to be ultrasonically bonded to) each of the opposing lower conductive structures 306a and 306b. As shown in FIG. 3 , each of the lower conductive structures 306a and 306b is formed on each of the Cu pillars 330a and 330b on the upper surface of the substrate 304 and on the upper surface of the Cu pillars 330a and 330b. and upper aluminum contact structures 316a and 316b respectively. Top aluminum contact structures 316a and 316b may be electroplated or sputtered on the respective top surfaces of the Cu pillars 330a and 330b. As can be seen, the semiconductor element 308 has been moved downward through the motion of the bonding tool 324 (as indicated by the arrows in FIG. 3), so FIG. 3 shows the conductive structures 306a, 322a; 306b , 322b). Using an ultrasonic transducer, ultrasonic energy (with optional heat and/or bonding force) is applied to the top semiconductor element 308 (e.g., via bonding tool 324) to bond with aluminum conductive structures 322a and 322b, respectively. An ultrasonic bonding portion is formed between the aluminum contact structures 316a and 316b of the

4A shows a portion of an ultrasonic bonding machine 400 that includes 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., in a vacuum), and the upper conductive structures 412a, 412b (i.e., sputtered aluminum bumps, aluminum studs) are formed at the lower surface. bumps, etc.). 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 406a and 406b (ie, sputtered aluminum bumps, aluminum stud bumps, etc.) are provided on the upper surface of the lower semiconductor die 402 . And the substrate 404 is supported by the support structure 450 . In the configuration shown in FIG. 4A, each of the upper conductive structures 412a and 412b is generally aligned with (and configured to be ultrasonically bonded to) each of the opposing lower conductive structures 406a and 406b. Details of structures 412a and 406b (before ultrasonic bonding) are shown in FIG. 4B. Referring back to FIG. 4A , the semiconductor element 408 has been moved downward through the motion of the bonding tool 424 (as indicated by the arrows in FIG. 4A ), so that the conductive structures 406a, 412a; 406b, 412b) is indicated. Using an ultrasonic transducer, ultrasonic energy 414 (along with optional heat and/or bonding force) is applied to the top semiconductor element 408 (e.g., via bonding tool 424) to form a deformed top aluminum conductive structure and An ultrasonic bond 428a, 428b is formed between each of the deformed lower aluminum contact structures (e.g., between deformed structure 412a' and deformed structure 406a' as shown in FIG. 4C). See completed ultrasonic bond 428a' formed.

5A shows a portion of an ultrasonic bonding machine 500 that includes a bonding tool 524 and a support structure 550 . The upper semiconductor element 508 is held by the holding portion 510 of the bonding tool 524 (eg, in a vacuum), and the upper conductive structures 522a, 522b (ie, the conductive aluminum pads 522a, 522b) are held. include The lower semiconductor element 560 includes a semiconductor die 502 bonded to (or otherwise supported by) a substrate 504 (eg, an FR4 support structure). Lower conductive structures 506a and 506b (ie, sputtered aluminum bumps, aluminum stud bumps, etc.) are provided on the upper surface of the lower semiconductor die 502 . And the substrate 504 is supported by the support structure 550 . In the configuration shown in FIG. 5A, each of the upper conductive structures 522a and 522b is generally aligned with (and configured to be ultrasonically bonded to) each of the opposing lower conductive structures 506a and 506b. Details of structures 522a and 506b (before ultrasonic bonding) are shown in FIG. 5B. As shown, the semiconductor element 508 has been moved downward through the motion of the bonding tool 524 (as indicated by the arrow in FIG. 5A), so FIG. shows the contact of Using an ultrasonic transducer, ultrasonic energy (along with optional heat and/or bonding force) is applied to the upper semiconductor element 508 (e.g., via bonding tool 424) to form a deformed upper aluminum conductive structure and a respective strain. Ultrasonic bonding portions 528a and 528b are formed between the lower aluminum contact structures (e.g., the finished structure formed between the deformed structure 522a' and the deformed structure 506a' as shown in FIG. see ultrasonic abutment 528a').

6A shows an ultrasonic bonding machine 600 that includes a bonding tool 624 and a support structure 650 . In Figure 6, a plurality of semiconductor elements have been bonded together in a stacked configuration, in accordance with the teachings of the present invention. Specifically, the semiconductor element 660a includes a semiconductor die 602a bonded to (or otherwise supported by) a substrate 604a, and conductive structures 606a and 606b (i.e., sputtered aluminum bumps, aluminum stud bumps, etc.) are provided on the upper surface of the semiconductor die 602a. Semiconductor element 660a is supported by support structure 650 .

Other semiconductor elements 660b (including corresponding semiconductor dies 602b bonded to or otherwise supported by substrate 604b, and conductive structures 612a, 612b on substrate 604b) are previously semiconductor bonded to element 660a. More specifically, the bonding tool 624 bonds the element 660b to the element 660a in advance (eg, bonding with ultrasonic waves), and ultrasonic waves are applied between each pair of aluminum conductive structures 612a, 606a; 612b, 606b. Junctions 628a and 628b were formed. Element 660b also includes conductive structures 606a' and 606b' bonded to the conductive structures of element 660c in steps described below. 6B shows a detailed view of an ultrasonic bond 628a including strained conductive structures 612a and 606a.

Similarly, another semiconductor element 660c (including a corresponding semiconductor die 602c bonded to or otherwise supported by the substrate 604c, and conductive structures 612a', 612b' over the substrate 604c). ) was previously bonded to the semiconductor element 660b. More specifically, the bonding tool 624 bonds the element 660c to the element 660b in advance (eg, ultrasonically bonding), so that each pair of aluminum conductive structures 612a', 606a'; 612b', 606b' ), ultrasonic joints 628a' and 628b' were formed between them. Element 660c also includes conductive structures 606a", 606b" that will be bonded to the conductive structure of element 660d in steps described below.

As shown in FIG. 6A , the upper semiconductor element 660d is held by the holding portion 610 of the bonding tool 624 (e.g., with a vacuum) and bonded to (or otherwise by the substrate) the substrate 604d. supported) semiconductor die 602d. Conductive structures 612a" and 612b" (ie, sputtered aluminum bumps, aluminum stud bumps, etc.) are provided on the lower surface of the substrate 604d. Conductive structures 612a" and 612b" are generally aligned with (and configured to be ultrasonically bonded to) opposing respective conductive structures 606a" and 606b". The semiconductor element 660d is moved downward in the motion of the bonding tool 624 (as indicated by the arrow in FIG. 6A). After this downward movement, contact will occur between each pair of conductive structures 612a", 606a"; 612b", 606b" (e.g., contact between structures 612a", 606a" before deformation through ultrasonic bonding see the detailed view of Fig. 6c). Using an ultrasonic transducer (not shown), ultrasonic energy is applied to the upper semiconductor element 604d through a bonding tool 624, between each pair of conductive structures 612a", 606a"; 612b", 606b". An ultrasonic joint is formed.

While certain exemplary upper and lower aluminum conductive structures are shown, those skilled in the art will appreciate that various shapes and designs of upper and lower aluminum conductive structures are acceptable within the teachings of the present invention.

7 is a flow diagram illustrating a method of bonding semiconductor elements together in accordance with an exemplary embodiment of the present invention. As will be appreciated by those skilled in the art, certain steps included in the flowcharts may be omitted, certain additional steps may be added, and also the order of the steps may be changed from the order shown. At step 700, a first semiconductor element (eg, including a semiconductor die on a substrate) is supported on a support structure of a bonding machine. A first semiconductor element (e.g., a top surface of a semiconductor structure) includes a plurality of first conductive structures composed at least in part of aluminum (e.g., structures 106a, 106b of element 160 in FIG. 1A; FIG. Structures 206a, 206b of element 260 in 2a; structures 306a, 306b of element 360 in FIG. 3a; structures 406a, 406b of element 460 in FIG. 4a; structures 406a, 406b of element 460 in FIG. Structures 506a, 506b of element 560 in FIG. 6A; and structures 606a", 606b" of element 660c in FIG. 6A). At step 702, the second semiconductor element is held by the retaining portion of the bonding tool of the bonding machine (eg, see elements 108, 208, 308, 408, 508, and 660d in corresponding figures). The second semiconductor element includes a plurality of second conductive structures (eg, on a lower surface of the second semiconductor element) composed at least in part of aluminum. At step 704, the first conductive structure and the second conductive structure are aligned with each other (eg, see 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 amount of bonding force. The predetermined amount of bonding force may be a single bonding force value, or may be a bonding force profile in which the actual bonding force changes during the bonding operation. In optional step 708, heat is applied to the plurality of aligned first conductive structures and/or second conductive structures. For example, the heat can 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 conductive structures and second conductive structures are ultrasonically bonded together to form an ultrasonic bond therebetween.

As is known to those skilled in the art, since the present invention bonds aluminum materials to aluminum materials, which can be easily achieved with ultrasonic energy and/or bonding force, often without the need for heat, the present invention requires a bonding operation at ambient/low temperature. have special advantages when

While the present invention has primarily been shown and described with respect to two pairs of conductive structures that are ultrasonically bonded together, the present invention is, of course, not limited thereto. In practice, a semiconductor package (eg, an advanced package) fabricated according to the present invention may have any number of conductive structures, and may have hundreds of pairs (even thousands of pairs) of conductive structures that are ultrasonically bonded together. Also, the conductive structures need not be bonded in pairs. For example, one structure may be bonded to two or more opposing structures. Thus, any number of conductive structures in one semiconductor element can be ultrasonically bonded to any number of conductive structures in another semiconductor element.

Although the present invention primarily describes (and illustrates) application of ultrasonic energy through a bonding tool (eg, the bonding tool is coupled with an ultrasonic transducer), the present invention is not limited thereto. Rather, ultrasonic energy can be delivered through any desired structure, such as through a support structure.

As the skilled artisan knows, the details of ultrasonic bonding can vary widely depending on the particular application. Nevertheless, certain 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 (e.g., pillar structure, etc.) so that the transducer resonance frequency substantially matches the resonance frequency of a given semiconductor element, and in this regard, The conductive structure can dynamically act as a cantilever beam. In another illustrative alternative, the transducer can be operated out of resonance with respect to the semiconductor element in a simple “driven” type manner.

Exemplary ranges for the energy applied to the ultrasonic transducer (eg, applied to the piezoelectric crystal/ceramic of the transducer driver) may be 0.1 kHz-160 kHz, 10 kHz-120 kHz, 20 kHz-60 kHz, etc. A single frequency may be applied during bonding, or multiple frequencies may be applied (eg, sequentially, simultaneously, or both). Scrub 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, among other configurations, the bonding tool holding the semiconductor element (herein as shown) or through a support structure supporting the semiconductor element. With particular reference to the embodiment illustrated herein (ultrasonic energy is applied through a bonding tool holding a semiconductor element), the rubbing is in a direction substantially parallel or substantially perpendicular to the longitudinal axis of the bonding tool (or in another direction). to) can be applied.

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

As discussed herein, bonding forces may also be applied during at least a portion of an ultrasonic bonding cycle. An exemplary range of bonding force is 0.1 kg to 100 kg. The bonding force can be applied at a constant value, or it can be a bonding force profile that changes during the bonding cycle. When the bonding force is controlled, the feedback control of the bonding force may be constant, ramped, or proportional based on one or more inputs (eg, ultrasonic amplitude, time, speed, strain, temperature, etc.).

As discussed herein, one or more of the semiconductor elements may be heated before and/or during the bonding cycle. An exemplary range of the temperature of the semiconductor element is 20°C-250°C. The heat (e.g., applied through one or both of the bonding tool and the support structure, or other element) may be applied at a constant value, or may be a temperature profile that changes during the bonding cycle, and may be controlled using feedback control. have.

While the present invention has primarily been shown and described in terms of forming an ultrasonic bond between aluminum conductive structures in respective semiconductor elements, the present invention is, of course, not limited thereto. That is, the teachings of the present invention can also be applied to forming ultrasonic bonds between conductive structures having different compositions. Examples of materials for the conductive structure to be bonded include aluminum and copper (ie, forming an ultrasonic bond between an aluminum conductive structure in one semiconductor element and a copper conductive structure in another semiconductor element); lead free solder (eg composed primarily 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 structure compositions (eg, indium) are contemplated.

As mentioned above, aspects of the present invention have been described with respect to aluminum materials included in various conductive structures of semiconductor elements, but the present invention is not limited thereto. That is, the conductive structure of the semiconductor element can include (or be formed of) a variety of other materials. For example, the conductive structure in the upper semiconductor element (eg, the element held and bonded using the bonding tool) and/or the conductive structure in the lower semiconductor element (eg, the element to which the upper conductive element is bonded) may be formed of copper. may (or may contain copper). The surface of these copper materials is subject to atmospheric contamination, i.e., the copper surface tends to be oxidized.

Accordingly, in certain embodiments of the present invention, at least one of the plurality of first conductive structures and the plurality of second conductive structures may be formed of (or may include copper). In this embodiment of the present invention, the entire conductive structure need not be formed of copper, but rather, the plurality of first conductive structures and the plurality of second conductive structures are the plurality of first conductive structures and the plurality of second conductive structures. Copper may be included in an interface portion adjacent to another conductive structure in the structure.

According to an aspect of the present invention, a coating (eg, an inorganic coating) may be applied to the surface of a copper conductive structure prior to ultrasonic bonding to prevent oxidation of the copper surface (eg, a connecting surface of a copper conductive structure such as a copper pillar). Specifically, such a coating is applied prior to bonding to the conductive structure on the upper semiconductor element (eg, the element held and bonded using a bonding tool) and/or the conductive structure on the lower semiconductor element (eg, the element to which the upper conductive element is bonded). It can be applied to the surface of the (eg, bonding surface).

Such a coating may be, for example, an inorganic coating (eg, a silicon oxynitride coating) applied as a thin frangible coating to the conductive structure (eg, the copper pillar conductive structure). Prior to forming flip chip interconnections between the respective conductive structures in the upper and lower semiconductor elements, the coating may serve to protect certain conductive structures (such as copper conductive structures) from oxidation or the like. Then, in conjunction with the ultrasonic flip chip bonding process, the coating(s) on each conductive structure are ultrasonically abraded away, thereby establishing metal-to-metal contacts/interconnections.

By providing a coating on the conductive structure, productivity and robustness of fine pitch flip chip packaging can be improved. For example, as flip chip packaging (which may include copper interconnects) becomes increasingly finer pitch, coatings may be applied to interconnects in a variety of applications including, but not limited to, die-to-substrate, die-to-die, and die-to-wafer applications. can be used to make

After piercing the coating (and/or other oxide layer formed on the conductive structure) using ultrasonic energy, a final bonding process between the conductive structure of the semiconductor element (e.g., which may include any desired combination of heat, pressure, and/or force) can) is completed.

8A-8C (in conjunction with the flowchart of FIG. 9), 10A-10C (in conjunction with the flowchart of FIG. 11), and 12A-12C (in conjunction with the flowchart of FIG. 13) show a semiconductor using the coating(s) described above. A system and method for forming interconnections between elements are shown. 9, 11 and 13 are flow charts illustrating methods of bonding semiconductor elements together in accordance with an exemplary embodiment of the present invention. As will be appreciated by those skilled in the art, certain steps included in the flowcharts may be omitted, certain additional steps may be added, and also the order of the steps may be changed from the order shown.

Specifically, referring to FIG. 8A , the upper semiconductor element 808 is held by the holding portion 810 of the bonding tool 824 (e.g., via a vacuum port formed on the holding surface of the holding portion 810). by a given vacuum). Upper semiconductor element 808 includes upper conductive structures 812a and 812b at its lower surface. The lower semiconductor element 860 includes a semiconductor die 802 bonded to (or otherwise supported by) a substrate 804 . Lower conductive structures 806a and 806b (eg, copper conductive structures such as copper pillars or other conductive structures) are provided on the upper surface of the lower semiconductor die 802 . A coating 806a1 is provided on the conductive structure 806a and a coating 806b1 is provided on the conductive structure 806b. And substrate 804 is supported by a support structure 850 (eg, a thermal block of machine 800, an anvil of machine 800, or other desired support structure). In the configuration shown in FIG. 8A (bonding preparation), each of the upper conductive structures 812a and 812b are generally aligned with the respective lower conductive structures 806a and 806b that face each other. The semiconductor element 808 is moved downward through motion of the bonding tool 824 (as indicated by arrow 826 in FIG. 8A). 8B shows the contact between each of the conductive structures 806a (including coating 806a1), 812a; 806b (including coating 806b1), 812b that occurs after this movement. Using an ultrasonic transducer (not shown, but labeled “USG” (ultrasonic generator) in the drawings), ultrasonic energy 814 is directed through bonding tool 824 to upper semiconductor element 808 and upper conductive structure ( 812a, 812b). For example, an ultrasonic transducer with bonding tool 824 may be held in the bonding head assembly of flip chip bonding machine 800 . During ultrasonic bonding, the lower conductive structures 806a and 806b may be held relatively motionless through the support of the lower semiconductor element 860 by the support structure 850 (e.g., the support surface of the support structure 850). may include one or more vacuum ports to secure the substrate 804 to the support structure 850 during bonding). Ultrasonic energy 814 (with optional bonding force and/or heat) can cause partial deformation of the conductive structure. For example, in FIG. 8C the conductive structures 806a, 806b (812a, 812b) are shown in a strained (or at least partially strained) state. In FIG. 8C an ultrasonic bond is formed between each pair of conductive structures. For example, an ultrasonic bond 828a is formed between the strained conductive structures 812a'/806a', and an ultrasonic bond 828b is formed between the strained conductive structures 812b'/806b'.

Referring specifically to FIG. 9 , at step 900 , a first semiconductor element (including a semiconductor die on a substrate, such as element 860 shown in FIG. 8A ) is supported on a support structure of a bonding machine. do. The first semiconductor element (eg, the top surface of the semiconductor structure) is a conductive structure (eg, see structures 806a, 806b of element 860 that includes coatings 806a1, 806b1, as shown in FIG. 8A). and a plurality of first conductive structures comprising a frangible coating on a contact surface (eg, a bonding surface for flip chip bonding). At step 902, a second semiconductor element is held by the holding portion of the bonding tool of the bonding machine (eg, see element 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 (eg, see FIG. 8A) and then brought into contact with each other (eg, see FIG. 8B). In step 906, ultrasonic energy is applied to the second semiconductor element (via a bonding tool carrying the second semiconductor element, as in FIG. 8B), so that an ultrasonic bond is formed between the pair of conductive structures (eg, FIG. 8C). In conjunction with the formation of ultrasonic bonds 828a, 828b in ), the conductive structure of the second semiconductor element pierces the respective coating of the conductive structure of the first semiconductor element.

Specifically, referring to FIG. 10A , the upper semiconductor element 1008 is held by the holding portion 1010 of the bonding tool 1024 (eg, via a vacuum port formed on the holding surface of the holding portion 1010). by a given vacuum). The upper semiconductor element 1008 includes upper conductive structures 1012a and 1012b (e.g., conductive structures formed of or comprising copper) at its lower surface, and a coating 1012a1 is provided on the conductive structure 1012a. A coating 1012b1 is also provided on the conductive structure 1012b. The lower semiconductor element 1060 includes a semiconductor die 1002 bonded to (or otherwise supported by) a substrate 1004 . Lower conductive structures 1006a and 1006b (eg, copper conductive structures such as copper pillars, or other conductive structures) are provided on the upper surface of the lower semiconductor die 1002 . And substrate 1004 is supported by a support structure 1050 (eg, a thermal block of machine 1000, an anvil of machine 1000, or other desired support structure). In the configuration shown in FIG. 10A (bonding preparation), each of the upper conductive structures 1012a and 1012b is generally aligned with each of the opposing lower conductive structures 1006a and 1006b. The semiconductor element 1008 is moved downward through motion of the bonding tool 1024 (as indicated by arrow 1026 in FIG. 10A). 10B shows the contact between the respective lower conductive structures 1006a, 1012a (including coating 1012a1); 1006b, 1012b (including coating 1012b1) that occurs after this movement. Ultrasonic energy 1014 is applied to the upper semiconductor element 1008 and the upper conductive structures 1012a and 1012b through a bonding tool 1024 using an ultrasonic transducer. For example, an ultrasonic transducer with bonding tool 1024 may be held in the bonding head assembly of machine 1000 . During ultrasonic bonding, the lower conductive structures 1006a and 1006b may be held relatively immobile through the support of the lower semiconductor element 1060 by the support structure 1050 (e.g., the support surface of the support structure 1050). may include one or more vacuum ports to secure the substrate 1004 to the support structure 1050 during bonding). Ultrasonic energy 1014 (with optional bonding force and/or heat) can cause partial deformation of the conductive structure. For example, in FIG. 10C, the conductive structures 1006a, 1006b; 1012a, 1012b are shown in a strained (or at least partially strained) state. In FIG. 10C, ultrasonic bonding is formed between each pair of conductive structures. For example, an ultrasonic bonding portion 1028a is formed between the strained conductive structures 1012a'/1006a', and an ultrasonic bonded portion 1028b is formed between the strained conductive structures 1012b'/1006b'.

Referring specifically to FIG. 11 , at step 1100, a first semiconductor element (eg, including a semiconductor die on a substrate, such as element 1060 shown in FIG. 10A) is supported on a support structure of a bonding machine. do. The first semiconductor element (eg, the top surface of the semiconductor structure) includes a plurality of first conductive structures (eg, see structures 1006a and 1006b of element 1060, as shown in FIG. 10A). In step 1102, a second semiconductor element is held by the holding portion of the bonding tool of the bonding machine (eg, see element 1008 in FIG. 10A). The second semiconductor element includes a plurality of second conductive structures (eg, on a lower surface of the second semiconductor element), the second conductive structures comprising a conductive structure (eg, a coating 1012a1 as shown in FIG. 10A). , cf. structures 1012a, 1012b) of element 1060 comprising 1012b1). In step 1004, the first conductive structure and the second conductive structure are aligned with each other (eg, see FIG. 10A) and then brought into contact with each other. In step 1006, ultrasonic energy is applied to the second semiconductor element (via a bonding tool carrying the second semiconductor element, as in FIG. 10B), so that an ultrasonic bond is formed between the pair of conductive structures (e.g., FIG. 10C). In connection with the formation of ultrasonic bonds 1028a, 1028b in ), the conductive structure of the first semiconductor element pierces the respective coating of the conductive structure of the second semiconductor element.

Referring specifically to FIG. 12A , the upper semiconductor element 1208 is held by the holding portion 1210 of the bonding tool 1224 (e.g., given through a vacuum port formed on the holding surface of the holding portion 1210). by vacuum). The upper semiconductor element 1208 includes upper conductive structures 1212a and 1212b (e.g., conductive structures formed of or comprising copper) at its lower surface, and a coating 1212a1 is provided to the conductive structure 1212a. A coating 1212b1 is also provided to the conductive structure 1212b. The lower semiconductor element 1260 includes a semiconductor die 1202 bonded to (or otherwise supported by) a substrate 1204 . Lower conductive structures 1206a and 1206b (eg, copper conductive structures such as copper pillars, or other conductive structures) are provided on the upper surface of the lower semiconductor die 1202 . A coating 1206a1 is provided on the conductive structure 1206a and a coating 1206b1 is provided on the conductive structure 1206b. Substrate 1204 is then supported by a support structure 1250 (eg, a thermal block of machine 1200, an anvil of machine 1200, or other desired support structure). In the configuration shown in FIG. 12A (bonding preparation), each of the upper conductive structures 1212a and 1212b is generally aligned with each of the opposing lower conductive structures 1206a and 1206b. The semiconductor element 1208 is moved downward through motion of the bonding tool 1224 (as indicated by arrow 1226 in FIG. 12A). 12B shows the respective conductive structures 1206a (including coating 1206a1), 1212a (including coating 1212a1), 1206b (including coating 1206b1), 1212b (including coating ( Including 1212b1))) shows the contact between. Using an ultrasonic transducer (not shown, but labeled “USG” (ultrasonic generator) in the drawings) ultrasonic energy 1214 is directed through bonding tool 1224 to upper semiconductor element 1208 and upper conductive structure ( 1212a, 1212b). For example, an ultrasonic transducer with bonding tool 1224 may be held in the bonding head assembly of machine 1200 . During ultrasonic bonding, the lower conductive structures 1206a and 1206b may be held relatively immobile through the support of the lower semiconductor element 1260 by the support structure 1250 (e.g., the support surface of the support structure 1250). may include one or more vacuum ports to secure the substrate 1204 to the support structure 1250 during bonding. Ultrasonic energy 1214 (with optional bonding force and/or heat) can cause partial deformation of the conductive structure. For example, in FIG. 12C, the conductive structures 1206a, 1206b; 1212a, 1212b are shown in a strained (or at least partially strained) state. In FIG. 12C, ultrasonic bonding is formed between each pair of conductive structures. For example, an ultrasonic bond 1228a is formed between the strained conductive structures 1212a'/1206a', and an ultrasonic bond 1228b is formed between the strained conductive structures 1212b'/1206b'.

Referring specifically to FIG. 13 , at step 1300 , a first semiconductor element (eg, including a semiconductor die on a substrate, such as element 1260 shown in FIG. 12A ) is supported on a support structure of a bonding machine. do. The first semiconductor element (eg, the upper surface of the semiconductor structure) is a conductive structure (eg, see structures 1206a, 1206b of element 1260 that includes coatings 1206a1, 1206b1, as shown in FIG. 12A). It includes a plurality of first conductive structures comprising a coating at the contact surface. At step 1302, a second semiconductor element is held by the retaining portion of the bonding tool of the bonding machine (eg, see element 1208 in FIG. 12A). The second semiconductor element includes a plurality of second conductive structures (eg, on a lower surface of the second semiconductor element), the second conductive structures comprising a conductive structure (eg, a coating 1212a1 as shown in FIG. 12A). , see structures 1212a and 1212b) of element 1208 including 1212b1). At step 1304, the first conductive structure and the second conductive structure are aligned with each other (eg, see FIG. 12A) and then brought into contact with each other. In step 1306, ultrasonic energy is applied to the second semiconductor element (via a bonding tool carrying the second semiconductor element, as in FIG. 12B), so that an ultrasonic bond is formed between the pair of conductive structures (eg, FIG. 12C). With respect to the formation of ultrasonic bonds 1228a, 1228b in ), the conductive structures of the second semiconductor element pierce the respective coatings of the conductive structures of the first semiconductor element (and vice versa, i.e., the first semiconductor element). the conductive structures of the second semiconductor element pierce each coating of the conductive structures of the second semiconductor element).

Each pair of conductive elements (806a, 812a in FIG. 8A; 806b, 812b; 1006a, 1012a in FIG. 10A; 1006b, 1012b; and 1206a, 1212a in FIG. 12A; 1206b, 1212b in FIG. 12A) can be bonded together at room temperature. (without heat added during the bonding process). Optionally, heat is applied to the top semiconductor element 806/1008/1012 via the bonding tool 824/1024/1224 to heat each top conductive element, such as (1) during a bonding process, and/or (2) During the bonding process, it is applied to the lower semiconductor element 860/1060/1260 through the support structure 850/1050/1250 to heat each lower conductive structure. Such selective heating (e.g., bonding tool and/or support structure, etc.) heating through) may be applied to any of the embodiments of the invention shown and described herein.

Additionally, during a bonding process (e.g., the process shown and described with respect to FIGS. 8A-8C, 10A-10C, and 12A-12C), the plurality of first conductive structures and second conductive structures may be pressed together with a predetermined amount of bonding force. have. The predetermined amount of bonding force may be a single bonding force value, or may be a bonding force profile in which the actual bonding force changes during a flip chip bonding operation.

Regardless of the specific elements discussed above, semiconductor elements 860, 808 (Figs. 8A-8C), 1060, 1008 (Figs. 10A-10C) and 1260, 1208 (Figs. 12A-12C) are multiple semiconductor elements configured to be bonded together. (eg, a memory device configured to be coupled to a processor). For example, lower semiconductor elements 860, 1060, 1260 may be semiconductor dies, wafers, panels, substrates, among many other possible elements configured to receive upper semiconductor elements (eg, dies) during a flip chip bonding process.

Conductive structures (i.e., 812a, 812b, 806a, 806b in FIGS. 8A-8C; 1012a, 1012b, 1006a, 1006b in FIGS. 10A-10C; and 1212a, 1212b, 1206a, 1206b in FIGS. 12A-12C) are conventional It is shown as a structure. These structures may take many different forms, such as conductive pillars, stud bumps (e.g., formed using a stud bumping machine), electroplated conductive structures, sputtered conductive structures, wire segments, bonding pads, contact pads, among others. have. Various other figures provided herein show specific examples of such structures. According to certain embodiments of the present invention, the conductive structure may be formed of copper or may include copper or some other material that is subjected to oxidation or the like.

Although the invention has been shown and described with reference to specific embodiments, the invention is not limited to the details shown. Rather, various modifications may be made in detail within the scope of equivalency of the claims and without departing from the invention.

Claims (25)

A semiconductor element ultrasonic bonding method for bonding semiconductor elements with ultrasonic waves,
(a) aligning a surface of a plurality of first conductive structures of a first semiconductor element with a respective surface of a plurality of second conductive structures of a second semiconductor element, wherein at least one of the first and second conductive structures one bonding surface comprising a frangible coating; and
(b) ultrasonically bonding the first conductive structure to each of the second conductive structures;
The coating is a ceramic coating semiconductor element ultrasonic bonding method. The method of claim 1,
The first semiconductor element is a semiconductor element ultrasonic bonding method of a semiconductor die. The method of claim 1,
The method of ultrasonic bonding of semiconductor elements, wherein each of the first semiconductor element and the second semiconductor element is a respective semiconductor die. The method of claim 1,
The method of claim 1 , wherein the first semiconductor element includes a semiconductor die. The method of claim 1,
Wherein each of the first semiconductor element and the second semiconductor element includes a respective semiconductor die. The method of claim 1,
Moving the first semiconductor element toward the second semiconductor element such that the lower surface of the first conductive structure is in contact with the upper surface of each second conductive structure. The method of claim 1,
The method of ultrasonically bonding semiconductor elements further comprising applying pressure between the first semiconductor element and the second semiconductor element during at least a portion of step (b). The method of claim 1,
The method of ultrasonically bonding semiconductor elements further comprising deforming the first conductive structure during step (b). The method of claim 1,
Step (b) is a method of ultrasonic bonding of semiconductor elements performed at ambient temperature. The method of claim 1,
The method of ultrasonically bonding semiconductor elements further comprising heating at least one of the first semiconductor element and the second semiconductor element during at least a portion of step (b). The method of claim 1,
A method of ultrasonically bonding semiconductor elements, further comprising heating the first semiconductor element during at least a portion of step (b) using a bonding tool holding the first semiconductor element. The method of claim 1,
The method of ultrasonically bonding semiconductor elements further comprising heating the second semiconductor element during at least a portion of step (b) using a support structure to support the second semiconductor element during step (b). The method of claim 1,
At least one of the plurality of first conductive structures and the plurality of second conductive structures is formed of copper semiconductor element ultrasonic bonding method. The method of claim 1,
Wherein each of the plurality of first conductive structures and the plurality of second conductive structures is a copper conductive structure. The method of claim 1,
At least one of the plurality of first conductive structures and the plurality of second conductive structures includes copper at an interface adjacent to the other of the plurality of first conductive structures and the plurality of second conductive structures. The method of claim 1,
Step (b) includes ultrasonically bonding the first conductive structure to each second conductive structure using a bonding tool that holds the first semiconductor element during step (b). The method of claim 16
wherein the bonding tool is coupled with an ultrasonic transducer for providing ultrasonic energy during step (b). The method of claim 16
wherein the bonding tool holds the first semiconductor element using a vacuum during step (b). delete The method of claim 1,
wherein the coating is a surface layer of a nitride, oxide or carbide of silicon or a mixture thereof. The method of claim 1,
The coating is a semiconductor element ultrasonic bonding method having a thickness of 10 Angstroms to 500 Angstroms. The method of claim 1,
The method of claim 1, wherein the coating has a thickness of 15 angstroms to 250 angstroms. A semiconductor element ultrasonic bonding method for bonding semiconductor elements with ultrasonic waves,
(a) aligning a surface of a plurality of first conductive structures of a first semiconductor element with a respective surface of a plurality of second conductive structures of a second semiconductor element, the first semiconductor element being attached to a support structure of a bonding machine. wherein the second semiconductor element is held in a bonding tool of the bonding machine, and wherein the bonding surface of the first conductive structure includes a frangible coating; and
(b) ultrasonically bonding the first conductive structure to each of the second conductive structures using the bonding tool;
The coating is a ceramic coating semiconductor element ultrasonic bonding method. A semiconductor element ultrasonic bonding method for bonding semiconductor elements with ultrasonic waves,
(a) aligning a surface of a plurality of first conductive structures of a first semiconductor element with a respective surface of a plurality of second conductive structures of a second semiconductor element, the first semiconductor element being attached to a support structure of a bonding machine. wherein the second semiconductor element is held in a bonding tool of the bonding machine, and the bonding surface of the second conductive structure includes a frangible coating; and
(b) ultrasonically bonding the first conductive structure to each of the second conductive structures using the bonding tool;
The coating is a ceramic coating semiconductor element ultrasonic bonding method. A semiconductor element ultrasonic bonding method for bonding semiconductor elements with ultrasonic waves,
(a) aligning a surface of a plurality of first conductive structures of a first semiconductor element with a respective surface of a plurality of second conductive structures of a second semiconductor element, the first semiconductor element being attached to a support structure of a bonding machine. supported by, wherein the second semiconductor element is held in a bonding tool of the bonding machine, wherein bonding surfaces of each of the first conductive structure and the second conductive structure include a frangible coating; and
(b) ultrasonically bonding the first conductive structure to each of the second conductive structures using the bonding tool;
The coating is a ceramic coating semiconductor element ultrasonic bonding method.

Images