CA1220877A - Method of making contact to semiconductor device - Google Patents

Method of making contact to semiconductor device

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Publication number
CA1220877A
CA1220877A CA000470019A CA470019A CA1220877A CA 1220877 A CA1220877 A CA 1220877A CA 000470019 A CA000470019 A CA 000470019A CA 470019 A CA470019 A CA 470019A CA 1220877 A CA1220877 A CA 1220877A
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CA
Canada
Prior art keywords
recited
contact
wire
group
semiconductor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
CA000470019A
Other languages
French (fr)
Inventor
David V. Lang
John M. Parsey, Jr.
Samson K. Milshtein
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
AT&T Corp
Original Assignee
American Telephone and Telegraph Co Inc
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Filing date
Publication date
Application filed by American Telephone and Telegraph Co Inc filed Critical American Telephone and Telegraph Co Inc
Application granted granted Critical
Publication of CA1220877A publication Critical patent/CA1220877A/en
Expired legal-status Critical Current

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    • H—ELECTRICITY
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    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
    • H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
    • H01L21/76—Making of isolation regions between components
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    • H01L24/85—Methods for connecting semiconductor or other solid state bodies using means for bonding being attached to, or being formed on, the surface to be connected using a wire connector
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K20/00—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating
    • B23K20/002—Non-electric welding by applying impact or other pressure, with or without the application of heat, e.g. cladding or plating specially adapted for particular articles or work
    • B23K20/004—Wire welding
    • B23K20/005—Capillary welding
    • B23K20/007—Ball bonding
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Abstract

METHOD OF MAKING CONTACT TO SEMICONDUCTOR DEVICE

Abstract This invention is a method of manufacturing a semiconductor and involves making of an electrical contact to said device at low temperatures. The making of the electrical contact includes providing a contact material at the end of a wire positioned by a guide, said contact material being at a temperature near its melting point and touching the contact material to a desired contact point.
The use of these steps results in low stress in the device.

Description

Vc a oll) ~ c~ ~o MRT~IOD OF~ }~ SEMICONDUCTOR DEVICES

Technical Field This invention relates to semiconductor devices and involves making electrical contacts to semiconductor devices by low temperature bonding.
Back~round of the Invention ____ ~
Many types of semiconductor devices require electrical contacts and, accordingly, methods of making electrical contactst that are both physically and electrically reliable, to semiconductor devices are extremely important in modern technology. In fact, the making of reliable electrical contacts to such devices is often a critical semiconductor device Eabrication step and, consequently, numerous methods have been developed for making such contacts. The semiconductor device must be appropriately contacted by a method that perrnits the desired connection to an external power source to be made without adversely altering device or materials characteristics.
One method that has been developed for making contacts is commonly referred to by those skilled in the art as thermocompression bonding. This method was developed for external lead attachment to the electrical terminals of semiconductor devices. The method is presently implemented by pushing a metal lead wire into firm physical contact with the desired metallized surface using a heated tool. The forces that are applied are typically high enough to produce appreciable plastic deformation of the lead wire. See, for example, "9th Annual Proceedings," ~ ~ , 1971, pp. 178-186, English et al.
Another method that has been developed is referred to by those skilled in the art as ultrasonic bonding. ~s this method is typically implemented in presen-t practice, an ultrasonic gel1erator provides high frequency electrical power which is delivered to a ~2;~B~ 77 transducer~ The transducer changes the electrical power into mechanical vibrations which are ultimately coupled to a bonding tool and the metal lead wire which transmits the energy to the bond interface during the bonding process.
See, for example, Semiconductor Mea~surement Microelectronic U~trasonic Bondinq, George G. Harman, Editor, National sureau of Standards, January, 1974, pp. 23-79.
Another bonding method, which is described in UO S. Patent 4,005,523 issued on February 1, 1977 to Samson Khaim Milshtein~ achieves bonding with low mechanical stress. The method was developed for gold wire bonding and produces localized high temperatures in the contacted material.
Consideration of the above briefly described processes leads one skilled in the art to the conclusion that while they are perfectly ade~uate for making many electrical bonds to semiconductor devices, they unfortunately suffer several drawbacks which may significantly and adversely effect device performance for several reasons. For example, during thermocompression bonding, the material is typically heated to an elevated temperature which may be as high as 350 to 400 degrees C.
A temperature as high as 200 degrees C may be utilized in ultrasonic bonding methods. The mechanical stresses that are applied to the semiconductor device during the bonding process can generate unwanted defects in the semiconductor material which can result in, for example, catastrophic failures during device operation. As there is no way to accommodate the different thermal expansion coefficients of the contact materials and the semiconductor rnaterials, defects may be generated in these methods. The defects generated by the lack of matching of thermal expansion coefficients may result in catastrophic failures during device operations when thermal cycling occurs. It should also be noted that the effects of heating ancl mechanical damage may be deleterious to both device performance and ~2~

lGngevity.
a~ ~ Invention In accordance with an aspect of the invention there is provided in a method of manufacturing a semi-conductor deYice, the method of making an electricalcontact to said device, said method Gomprising forming an end portion of a wire, being used in making said electrical contact, into an enlarged end portion configuration, adding a contact material to said enlarged end portion of the wire positioned by a guide; keeping said contact material at a temperature near its mel~ing point; and touching said contact ma-terial to a desired contact point, said touching resulting in heating a localized area around said contact point and in coupling of said enlarged end point con-Eiguration of the wire and of said contact material so as to orm an electrical connection.
In accordance with this invention, electricalcontacts may be made to semiconductor devices comprising semiconductor materials or metallized bonding pads on semi-conductor materials by heating the end of a wire which is, for example, attached to a wire bond tip or another typeof guide; providing a contact material at the end of said wire, and touching said end of said wire to the desired contact point. The wire comprises an electrically con-ducting material. The contact material is typically a metal. In one preEerred embodiment, a ball comprising thewire material is formed and the contact metal is added to the ball. The ball is advantageously formed by subjecting -the wire to a burst from a torch such as a hydrogen flame.
The contact metal may have a single constituent or it may be an alloy. In the latter case, additional metals may also be added to the end of the wire to form an alloy, iOeO, the metals may be separately contacted. The alloy is typically an appropriate metal alloy having character-istics, such as a low melting point and optimum metal-3'77 - 3a -lurgica] characteristics, consistent with the requirements of device operation, such as operating ternperature, etc.
The wire need not be heated initially as long as the con-tact metal is maintained at a temperature near its melting -temperature after it is added to the end of the wire. When the ball or wire end contacts the surface, it does so under its own weight and forms a bond with the surface. The molten alloy heats a localized portion of the substrate;
the ball then cools and the alloy solidifies to form a bond. The metals, forming the alloy, may be selectecl to op-timize device electrical properties, mechanical strength, and thermal expansion characteristics. ~hen the wire bond tip is pulled away from the bond, either the tail of the wire is utilized to form a second electrical contact or the tail is left Eor other types of electrical connections. The method of this invention is advanta~eously employed in fabricating bonds to damaqe-sensitive Group III-V semiconductor devices such as light-emitting diodes, lasers, and photodetectorsO

I
FI~. 1 is a sectional view of the wire bond apparatus after the wire has been heated to form a ball;
and FIG. 2 is a sectional view of a bond made according to our invention.
For reasons of clarity, the elements of the device are not drawn to sca]e.
Detailed ~ n Our invention is expeditiously implemented with a conventional wire bonder, and one embodiment, as well as several variations, will be discussed. Other variations will be readily apparent to those skilled in the art. Such wire bonders are well known to those skilled in the art and need not be described in detail. The wire, which is attached to, or carried by 7 a heated guide, and comprises ~old, aluminum, or another suitablé material, is heated to a temperature slightly above the melting point of the contact metal. The wire is then extended from the guide tip and subjected to means which form a ball comprising the wire metal at the end of the wire. Typical means comprise a burst from the small torch, such as a hydrogen flame, which is present in typical wire bonding apparatus. The ball is supported by the wire~ and the ball is held away from the guide tip.
The ball is now contacted to an appropriate contact metal, which may have a single constituent or be an alloy. The contact metal may be in solid or liquid form. The metal or metal alloy is picked up by the metal ball and either softens or alloys with the ball metal. The contact metal is typically a metal alloy, i.e., it comprises at least two metals, which have characteristics consistent with the requirements of device operation. The structure is depicted in EIG. 1 and com~rises cluide ~%i~ 7 assembly 1, wire 3, ball 5, and alloy region 7.
Alternatively, the end of the heated wire may contact the contact metal without a ball being formed.
The guide assembly carries the wire and alloyed ball to the desired contact point, if it is not already at that point, where the ball is lowered onto the contact site on the semiconductor device. The resulting structure is depicted in FIG. ~ with the hatched region 9 indicating a bonding pad or semiconductor device. It should be noted that the ball contacts the s~rface under its own weight and th~s subjects the contacted structure to negligible heating and minimal mechanical stress. The contact or bond is typically Eormed by the alloy metal which is on the small ball, and as the temperature is low, the amount of heat transmitted to the device surface during the bonding operation is small. The alloy solidifies in a short time, e.g., 1 to 2 seconds. Consequently, the device surace region is subjected only to a small thermal perturbation and, in essence, the bonding is a low stress process. This is advantageous because it minimizes diffusion of the contact materials and impurities in the device within the region of contact and thus does not alter the local materials properties. This was demonstrated on InP-Schottky barrier diode structures which are extremely sensitive to contact formation induced damage.
The bond dimensions are limited primarily by the size of the wire and the ball formed by the flame. The smallest bond dimension easily obtainable appears to be the wire diameter. The relevant parameters which control the size of the ball are the diameter of the wire and -the length of the wire exposed to the Elame, i.e., the amount of material melted~ The minimum ball dimension is approximately the wire diameter. In practice, the actual contact area is somewhat smaller than the ball diameter. A
maximum ball diameter of approximately 6 to 8 wire diameters can be EormedO The diameter oE the wire which is heated is not critical and wires of essentially any size 7~

may be utilized provided that they are consistent with the requirements of the device structure, the guide structure and flame capabilities. In other wordst the desired site of the bond is one of the parameters which cletermines the appropriate wire size. For example, contact pads and devices having dimensions of approximately 60 to 80 ~m may be readily contacted with the method. Smaller contacts may be made if desired. Furthermore, if still larger contact areas or flat contact surfaces are desired, the ball may be deformed by mechanical means. The deformation may be performed by pressing the ball to a suitable nonbonding surface with the wire ~uide tip. This step rnay be executed either prior to, or after, contacting the metal alloy material.
The positioning of the metal ball Eor bonding is easily controlled by the guide apparatus and is thus limited by the mechanical accuracy of the guide and the operator and/or machine capabilities. Of course, this step can be automated. It will be appreciated by those skilled in the art that the limitation regarding operator capabilities is similar to that present in the operation of the standard wire bonding ap aratus rather than a limitation unique to our method. The actual position of the bond can in practice be controlled to a fraction of a ball diameter.
Reproducibility of the contact characteristics is limited by the consistency with which the desired length of wire is exposed to the flame7 that is, the ball size; the quantity of alloy metal picked up by the ball; and precision of the alloyed bàll placement. In practice, the length of exposed wire may be precisely controlled and the ball dimensions may be similarly controlled. The quanti-ty of the alloy metal picked up may be accurately controlled by the use of metal preforms or a molten metal or metal alloy bath.
Contacts may be formed on a variety of surfaces.
For example, the contacts may be forme~ on either bare 3~2~

semiconductor or metallized surfaces. Compound semiconductors selected from the qroup consisting of Group I[I-V semiconductors may be contac-ted by this method.
The quality of the electrical and physical characteristics of the contacts fabricated by our method is predicated on the interaction of the alloyed meta] and the contacted material. Appropriate alloy systems which exist for various semiconductors and contact metals are well known to those skilled in the art and there is therefore essentially no limitation on the materials which can be bonded. In practice, alloys can be selected which have characteristics, for example, thermal expansion coefficients, that are similar to those of the contacted surface. The ability to utilize various alloy systems enab3es thermal expansion coefficients to be matched between the contact alloy and the material contacted, e.g., semiconductor or semiconductor metallization, while the alloy composition is also selected to minimize bonding temperature thus again minimizing stresses in the device structure.
The bond strength depends on the ~uality of the semiconductor/alloy or metal/alloy interaction. It has been found that mechanical strength of bonds made by this method are sufficient to permit lifting by a force of greater than 7 grams utilizing gold wires 25 ~m in diameter and greater than 12 grams utilizing gold wires 50 ~m in diameter.
Bond failure was observed to occur by two primary mechanisms: first, by the wire parting either at the 3~ junction of the wire and bàll or in the main part of the wire, i.e., ductile fracture; and second, by the contact ball material parting from the alloy which is bonded to the surface region. Adhesion is influenced by the chemical-mechanical interaction of the contact alloy and the contact material. Bond formation may be further enhanced by utilizing fluxes in the contacting process. The flux may be solid~ liquid, or gas. The flux may be used in an ~2~8~'7 intermediate step between the contact alloy pickup and contact formation and/or be-tween heating the wire and contact alloy pickup.
It will be readily appreciated that many materials may be used with our method. Any metal materia1s which are bonded presently by thermocompression or ultrasonic bonding techniques may be bonded with our technique.

Claims (21)

Claims:
1. In a method of manufacturing a semiconductor device, the method of making an electrical contact to said device, said method comprising forming an end portion of a wire, being used in making said electrical contact, into an enlarged end portion configuration, adding a contact material to said enlarged end portion of the wire positioned by a guide;
keeping said contact material at a temperature near its melting point; and touching said contact material to a desired contact point, said touching resulting in heating a localized area around said contact point and in coupling of said enlarged end point configuration of the wire and of said contact material so as to form an electrical connection.
2. A method as recited in claim 1 in which said contact material comprises a contact metal.
3. A method as recited in claim 2 in which said contact metal comprises at least two metals.
4. A method as recited in claim 2 further comprising the step of adding a flux to the end of said wire.
5. A method as recited in claim 4 in which said contact point comprises a metallization layer.
6. A method as recited in claim 5 in which said contact point further comprises a semiconductor material under said metallization layer.
7. A method as recited in claim 6 in which said semiconductor is selected from the group consisting of Group IV and Group III-V and Group II-VI compound semiconductors.
8. A method as recited in claim 1 further comprising the step of forming a ball comprising said wire metal on the end of said wire.
9. A method as recited in claim 1 in which said forming is by heating to a temperature sufficient to melt said wire.
10. A method as recited in claim 8 in which said forming is by heating to a temperature sufficient to melt said wire.
11. A method as recited in claim 9 or 10 in which said heating is by exposing to a torch.
12. A method as recited in claim 8 further comprising the step of adding a flux to the end of said wire.
13. A method as recited in claim 12 in which said contact point comprises a metallization layer.
14. A method as recited in claim 13 in which said contact point further comprises a semiconductor material under said metallization layer.
15. A method as recited in claim 14 in which said semiconductor is selected from the group consisting of Group IV and Group III-V and Group II-VI compound semiconductors.
16. A method as recited in claim 12 in which said contact point comprises a semiconductor.
17. A method as recited in claim 16 in which said semiconductor is selected from the group consisting of Group IV and Group III-V and Group II-VI compound semiconductors.
18. A method as recited in claim 4 in which said contact point comprises a semiconductor.
19. A method as recited in claim 18 in which said semiconductor is selected from the group consisting of Group IV and Group III-V and Group II-VI compound semiconductors.
20. A method as recited in claim 2 in which said adding a contact metal step contacts a molten bath.
21. A method as recited in claim 4 in which said adding a contact metal step contacts a molten bath.
CA000470019A 1983-12-19 1984-12-13 Method of making contact to semiconductor device Expired CA1220877A (en)

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US56316883A 1983-12-19 1983-12-19
US563,168 1983-12-19

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Publication number Priority date Publication date Assignee Title
US5189507A (en) * 1986-12-17 1993-02-23 Raychem Corporation Interconnection of electronic components
US4955523A (en) * 1986-12-17 1990-09-11 Raychem Corporation Interconnection of electronic components
US4948030A (en) * 1989-01-30 1990-08-14 Motorola, Inc. Bond connection for components
US5683255A (en) * 1993-12-03 1997-11-04 Menze; Marion John Radio frequency connector assembly
US5455390A (en) * 1994-02-01 1995-10-03 Tessera, Inc. Microelectronics unit mounting with multiple lead bonding
US5688716A (en) 1994-07-07 1997-11-18 Tessera, Inc. Fan-out semiconductor chip assembly
US6429112B1 (en) 1994-07-07 2002-08-06 Tessera, Inc. Multi-layer substrates and fabrication processes
US5830782A (en) * 1994-07-07 1998-11-03 Tessera, Inc. Microelectronic element bonding with deformation of leads in rows
US6828668B2 (en) 1994-07-07 2004-12-07 Tessera, Inc. Flexible lead structures and methods of making same
US5518964A (en) * 1994-07-07 1996-05-21 Tessera, Inc. Microelectronic mounting with multiple lead deformation and bonding
US6117694A (en) * 1994-07-07 2000-09-12 Tessera, Inc. Flexible lead structures and methods of making same
US6361959B1 (en) 1994-07-07 2002-03-26 Tessera, Inc. Microelectronic unit forming methods and materials
US5798286A (en) * 1995-09-22 1998-08-25 Tessera, Inc. Connecting multiple microelectronic elements with lead deformation
US6133072A (en) * 1996-12-13 2000-10-17 Tessera, Inc. Microelectronic connector with planar elastomer sockets
US20060186179A1 (en) * 2005-02-23 2006-08-24 Levine Lee R Apparatus and method for bonding wires

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GB1434833A (en) * 1972-06-02 1976-05-05 Siemens Ag Solder carrying electrical connector wires

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IL73844A0 (en) 1985-03-31
JPS60154537A (en) 1985-08-14
SG16088G (en) 1988-07-08
GB2151529B (en) 1987-09-30
GB2151529A (en) 1985-07-24
KR850005137A (en) 1985-08-21

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