DE102010016216A1 - Method for wire bonding wire bonding contact region on wire bonding structure of silicon carbide junction FET of e.g. semiconductor component in e.g. integrated power switching circuit, involves cleaning wire bonding contact region - Google Patents

Abstract

The method (100) involves cleaning wire bonding contact region using a nitrogen and hydrogen mixture. The wire bonding contact region is wire bonded to the wire bonding structure. The bonding region of the die is die bonded to the die-bond structure. The bond structure comprises a lead frame structure, where the bond structure is made of copper and/or copper alloy. The cleaning of the wire bond contact region and the wire bonding are performed in the same atmosphere. The wire bonding region is made of copper and/or copper alloy. An independent claim is also included for a die comprising a wire bonding contact region.

Description

Various embodiments generally relate to a wire bonding method, a method of cleaning a wire bonding portion of a die, and dies.

In the manufacture of integrated circuit dies, wire bonding processes are often used to connect a die having electrical circuits to a pin of a component package. It is also becoming more and more desirable to use copper-metal compounds. However, direct wire bonding to copper is quite complex due to the instability of natural copper oxide at conventional wire bond temperatures, which typically can range from about 130 ° C to about 170 ° C and higher.

In a conventionally packaged device, only chip-to-chip devices having poor thermal performance and poor switching performance, as well as discrete devices, are available at a high cost.

In various embodiments, a method of wire bonding a wire bonding contact area of a die to a wire bonding structure is provided. The method may include cleaning the wire bonding contact area using forming gas; and wire bonding the wirebond contact region to the wirebond structure. According to one embodiment, the method may further include die-bonding a die bond region of the die to a die bond structure. The die bond structure may include or be a frame structure, for example, a lead frame structure.

Furthermore, the die bonding structure may comprise or be made of or consist of copper or a copper alloy.

The cleaning of the wire bonding contact area and the wire bonding are carried out according to one embodiment in the same atmosphere, in other words without breaking the atmosphere.

The method further comprises providing a die bond structure as well as cleaning a portion of the die bond structure to be die bonded to a die bond region of the die using a forming gas.

The cleaning of the part of the die bond structure and the cleaning of the wire bond contact region are carried out in the same atmosphere according to another embodiment.

According to another development, the wire bonding region comprises or consists of copper and / or a copper alloy.

According to another embodiment, there is provided a method of cleaning a wire bonding contact area of a die, the method comprising providing a die having a wire bonding contact area comprising copper and / or a copper alloy or made of copper and / or a copper alloy, as well as a Cleaning the wire bonding contact area using forming gas.

In accordance with yet another embodiment, there is provided a die having a wirebond contact region formed or made of copper and / or a copper alloy, wherein at least a portion of the wirebond contact region has a surface roughness of less than about 2 microns. According to one embodiment, at least part of the wire bonding contact area has a surface roughness of less than about 1 μm.

According to another embodiment, the die further comprises a die bond region and a die bond structure die-bonded to the die bond region of the die.

The die bond structure may have a frame structure, for example a lead frame structure.

Furthermore, the die-bonding structure may comprise copper and / or a copper alloy or consist of copper or a copper alloy.

The die may be a semiconductor component, for example a power semiconductor component, for example a semiconductor component, for example a power semiconductor component.

In accordance with yet another embodiment, there is provided a die having a wirebond contact region comprising or consisting of copper or a copper alloy, wherein a portion of the wirebond contact region is oxidized, thereby forming a copper oxide layer, the copper oxide layer having a thickness of less than 100 nm ,

The die may further include a wirebond structure bonded to the wirebond contact region, eg, wire bonded, with the copper oxide layer disposed adjacent the wirebond structure.

The die may further include a die bond region and a die bond structure die-bonded to the die bond region of the die.

According to one embodiment, the die-bond structure has a frame structure, for example a lead-frame structure.

The die bond structure according to various embodiments comprises or is formed from or consists of copper and / or a copper alloy.

The die may be a semiconductor component or a semiconductor device, for example a power semiconductor device or a power semiconductor component.

The die may include a plurality of semiconductor components.

Embodiments of the invention are illustrated in the figures and are explained in more detail below.

In the figures, like reference numerals are generally used to designate the same or similar parts throughout all different figures. The figures are not necessarily to scale, it was instead a matter of explaining the principles of various embodiments.

In the following description, various embodiments of the invention are described with reference to the following figures.

Show it:

1 a flowchart illustrating the process for producing a Dies according to an embodiment;

2 a method of wire bonding a wire bonding contact area of a die to a wire bonding structure according to an embodiment;

3 a method of cleaning a wire bonding contact area of a die according to an embodiment;

4 a process of manufacturing a die comprising a die bonding and a wire bonding according to an embodiment;

5 a die bond and wire bond arrangement within the same atmosphere according to an embodiment;

6 a die bond and wire bond arrangement which provides time coupling between the die bonding process and the wire bonding process according to an embodiment;

7 a cross section of a Dies according to an embodiment;

8th a cross section of a power semiconductor dies according to another embodiment; and

9 a cross-sectional view of a Dies according to an embodiment.

The following detailed description refers to the attached figures, which show, by way of example, specific details and embodiments in which the invention may be practiced.

The term "example" is used below in the meaning "serving as an example, or an explanation". Any embodiment or design described herein which is declared as an "example" is not necessarily to be construed as preferred or advantageous over other embodiments or other embodiments or designs.

1 shows a flowchart 100 , which illustrates a process for manufacturing a die according to an embodiment. It should be noted that the flowchart illustrates a simplified process for producing a die and various additional processes may be provided depending on the type of die and the particular characteristics of the selected process.

The process 100 starts in 102 with a wafer assembly. In various embodiments, the wafer may include a plurality or a plurality of dies.

The dies can be of the same type or of different types. In various embodiments, each of the dies may include an electrical component or a plurality of electrical components or devices, such as one or a plurality of semiconductor components or semiconductor devices.

In various embodiments, each die may include one or a plurality of semiconductor components including, for example, logic semiconductor components (such as logic gate) or memory semiconductor components (such as memory cells (eg, volatile memory cells (eg, dynamic memory cells) Dynamic Random Access Memory (DRAM) memory cells), or nonvolatile memory cells (eg, flash memory cells, such as charge-gate memory cells (charge-trapping memory cells) or any other type of memory cells (For example, resistive memory cells (for example Phase Change Random Access Memory (PCRAM) memory cells or Magnetoresistive Random Access Memory (MRAM) memory cells.) Further, in various embodiments, each may include one or more power semiconductor components Power semiconductor devices such as power metal oxide semiconductor field effect transistors (power MOSFET) components (eg, one or more junction field effect transistors) effect transistor, JFET), vertical diffused MOS field effect transistors (VDMOS) (also referred to as double diffusion MOS or single DMOS)), or power bipolar junction transistor components (e.g. a plurality of insulated gate bipolar transistors (IGBTs) or one or more thyristors (eg, one or more integrated gate-commutated thyristors (IGCPs) or one or more triacs. Other implementations of a power metal oxide semiconductor field effect transistor can be seen in a VMOS FET having a V-groove in the gate region or a UMOS FET (also referred to as a trench MOS) with the gate electrode buried in a trench etched into the silicon. This results in a vertical channel. The main advantage of this type of structure is the absence of the JFET effect. The name of the structure comes from the U-shape of the trench. Yet another implementation of a power metal oxide semiconductor field effect transistor can be seen in a CoolMOS FET, which is especially suited for voltages beyond 500 V and which uses a charge compensation principle. Thus, the resistance in the epitaxial layer, which most contributes to the resistance in a high voltage MOSFET, is reduced by a factor of greater than 5. In alternative embodiments, other types of power semiconductor components or power semiconductor devices may be provided in one die. In various embodiments, power semiconductor components may be understood as semiconductor components that may be used as switches or rectifiers in electronic power circuits (eg, switching mode power supply). They may also be referred to as power devices or, for example, when used in an integrated circuit, as integrated power circuits (power IC).

Then you can in 104 the dies may be singulated, for example, by means of sawing, etching, breaking, etc. Any process for dicing the dies of the wafer may be used. It should be noted that the process 104 may be omitted or each isolated Which may have a plurality of Dies, which may still be arranged (after singulation) on a common wafer section.

In 106 For example, a die bonding process may be provided for each die or a plurality of dies that are integrated together on the same wafer section. The die bonding process 106 will be explained in more detail below.

Then in can 108 a wire bonding process may be provided for each die or for a plurality of dies. The wire bonding process 108 will be explained in more detail below. The wire bonding process 108 may include one or more thick wire bonding processes and / or one or more thin wire bonding processes.

In various embodiments, the die bonding process 106 and the wire bonding process 108 be executed simultaneously, or in the same atmosphere (in other words, without a break in the atmosphere), or in a predefined time-coupling (in other words, the die-bonding process 106 and the wire bonding process 108 may be performed within a rather (e.g. predefined) short period of time (in other words, for example, the wire bonding process 108 be executed (for example, started or terminated) at the latest within the (for example, predefined) time period after the die-bonding process 106 for example, within a time period of hours, for example, a maximum within a time period of about 24 hours, for example, a maximum within a time period of about 18 hours, for example, a maximum within a time period of about 15 hours, for example, a maximum within a time period of about 12 For example, within a maximum period of about 10 hours, for example, a maximum within a period of about 8 hours, for example, within a maximum period of about 6 hours, for example, within a maximum period of about 4 hours, for example within a period of about 2 hours, for example, within a maximum period of about one hour or less. This close (for example, predefined) Connection between the die bonding process 106 and the wire bonding process 108 according to various embodiments is in 1 by reference numeral 110 symbolizes.

Then you can in 112 The die-bonded and wire-bonded dies are molded so that a wrapped die is formed. Then, for example, after a plating process for forming the contact pads of the packaged dies, the packaged die in 114 for example tested.

As will be explained in more detail below, the above relationship between the die bonding process 106 and the wire bonding process 108 also be omitted. Furthermore, in various embodiments, the die bonding process 106 be omitted if it is not needed.

2 shows a method 200 for wire bonding a wire bonding contact area of a die to a wire bonding structure according to an embodiment. The procedure 200 points to, in 202 , cleaning the wire bonding contact area using forming gas, and, in 204 , Wire bonding the wire bonding contact area to the wire bonding structure.

In various embodiments, forming gas may be understood as a mixture of hydrogen (eg, up to 5.7% or more) and nitrogen. Forming gas is also referred to as a "decoupled ammonia atmosphere" due to the reaction that generates the forming gas: 2NH ₃ → 3H ₂ + N ₂ . For example, in various embodiments, forming gas may be produced by thermal cracking of ammonia in an ammonia cracker (ammonia crusher) or forming gas generator.

In various embodiments, the method may further include die-bonding a die bond region of the die to a die bond structure. In various embodiments, the die bond structure may include a frame structure (in other words, a die (chip) carrier structure), for example, a lead frame structure.

In various embodiments, the die bond structure may include or consist of copper and / or a copper alloy (eg, a low alloy copper alloy (e.g., in a range of about 0% to about 3%, for example, in a range of about 0.5% to about 2.5 %, for example, in a range of 1% to about 2%) of one or more of iron (Fe), phosphorus (P), sulfur (S), or any other suitable material or materials, in various embodiments For example, any material used in the copper alloy that increases its corrosion stability). In various embodiments, cleaning of the wire bonding contact area and wire bonding may be performed in the same atmosphere (for example, in the same forming gas atmosphere). In other words, the forming gas used in the wire bonding process to clean the wire bonding contact area may also be used to clean the die bond contact area or die bond areas during the die bonding process. In various embodiments, the method may further include providing a die bond structure and cleaning a portion of the die bond structure to be die bonded to the die bond region using forming gas. In various embodiments, cleaning of the part of the die bond structure and cleaning of the wire bond contact region may be performed in the same atmosphere. In various embodiments, the die bonding may be performed at a temperature in a range of about 250 ° C to about 500 ° C, for example, at a temperature in a range of about 300 ° C to about 450 ° C, for example, at a temperature in a range of about 350 ° C to about 400 ° C. In various embodiments, the wire bonding may be performed at a temperature in a range of about 0 ° C to about 100 ° C, for example at a temperature in a range of about 15 ° C to about 75 ° C, for example at a temperature in a range from about 20 ° C to about 50 ° C. In various embodiments, wire bonding may be performed at room temperature. In various embodiments, the wire bonding region may include or consist of copper and / or a copper alloy (eg, a low alloy copper alloy (eg, in a range of about greater than 0% to about 3%, for example, greater than about 0.5%). to about 2.5%, for example, in a range of about 1% to about 2%) of one or more of iron (Fe), phosphorus (P), sulfur (S), or any other suitable material, in various embodiments For example, any material that increases its corrosion resistance may be included in the copper alloy.

3 shows a method 300 for cleaning a wire bonding contact area of a die according to an embodiment. The procedure 300 points to, in 302 by providing a die having a die bond contact area comprising copper and / or a copper alloy, or copper and / or a copper alloy, and, in 304 , cleaning the wire bonding contact area using forming gas.

For example, in various embodiments, the copper alloy may have a low content of (for example, in a range of about 0% to about 3%, for example, in a range of about 0.5% to about 2.5%, for example, in a range of about 1%. to about 2%) one or more of the materials iron (Fe), phosphorus (P), sulfur (S) or any other material or materials; in various embodiments, any material may be used or included in the copper alloy that enhances its corrosion stability).

4 FIG. 12 shows a process for making a die including die bonding and wire bonding according to an embodiment in a process arrangement. FIG 400 ,

In various embodiments is a tunnel 402 provided, which is filled with a forming gas and so with a Formiergasfluss in the tunnel 402 wherein the Formiergasfluss over the exposed portions of the respective structures of the dies during the respective process stages for cleaning the same is used, for example during the die bonding process and the Drahtbondprozesses, as will be explained in more detail below. In various embodiments, the forming gas flow is in the tunnel 402 cleaning the exposed metallic areas (for example, including copper or a copper alloy as described above), for example, the metal die bonding areas and / or the wire bonding areas provided on the die, or in the case of the die bonding process, for example also ( or only) on the surfaces (or part of the surface) of a provided frame structure, such as a provided lead frame structure.

The tunnel 402 is with a Formiergasquelle 404 coupled (for example, implemented as a forming gas container 404 , filled with forming gas 406 ) by means of a gas line 408 , The tunnel is a structure in which various processes are performed, substantially or completely in the same atmosphere, in other words, without a break in the atmosphere, for example, in the same forming gas atmosphere.

In various embodiments, one or more frame structures 410 for example, one or more lead frames 410 , in the tunnel 402 introduced. The frame structure (s) 410 may comprise copper and / or a copper alloy or consist of copper and / or a copper alloy. In various embodiments, the frame structure or frame structures may or may 410 consist of copper and / or a copper alloy. In various embodiments, the frame structure (s) may or may 410 have a surface which is wholly or partially made of copper and / or a copper alloy. The forming gas in the tunnel 402 Cleans the exposed copper surfaces or the exposed copper surface of the frame structure (s) 410 ,

The imported frame structures or the introduced frame structure 410 can then in the tunnel 402 be transported to a die bond material dispensing machine 412 which die-bonding material such as copper or a copper alloy (alternatively tin or any other die bonding material such as AuSn) on predefined areas of the frame structure (s) 410 for example, to areas of the exposed copper surface (s) of the frame structure (s) 410 ,

The frame structure (s) 410 with the applied die bonding material 414 can then in the tunnel 402 to a die-bonder 416 be transported. The die bonder 416 is set up to provide a die 418 or more this 418 to the frame structure or frame structures 410 and then performing a die bonding process (eg, the die bonding process may be performed at a temperature in a range of about 250 ° C to about 500 ° C, for example, a temperature in a range of about 300 ° C to about 450 ° C for example at a temperature in a range of about 350 ° C to about 400 ° C).

The resulting structure of the frame structure 410 and of this 418 that belongs to the frame structure 410 The die-bonded is from the die bonder 416 can be spent and then in the tunnel 402 to a nailhead dispenser 420 be transported, which nailhead ("nailhead") material 422 such as copper or a copper alloy (alternatively, tin or any other wire bonding material) on predefined wire bond areas of the die 418 For example, on wire bond contact areas of the dies 418 , The nailheads 422 can be understood as small bumps which serve as a contacting base for subsequent wire bonding on the wire bond areas of the die 418 serve. It should be noted that the nailhead dispensing machine 420 is optional. Furthermore, in various embodiments, the nail-head dispensing machine 420 be implemented in the wire bonder 424 , as will be explained in more detail below.

The resulting structure of the frame structure 410 and of this 418 with the nail heads 422 on the respective areas of the die which are to be wire-bonded may be in the tunnel 402 to a wire bonder 424 in which one or more wire bond structures (eg, bond wires) may be wire bonded to the wire bond contact area or wire bond contact areas (more specifically, to the nail heads 422 the particular area) (which may or may be made of copper or a copper alloy as described above) of the die 418 , In various embodiments, the one or more wire bond structures may include or consist of copper or a copper alloy, as described above. Thus, the arrangement of a wirebond structure and the respective wirebond contact region to which the wirebond structure is bonded is illustratively a copper-on-copper "material system".

Thus, illustratively, a copper-on-copper contact may be provided, wherein forming gas is provided for cleaning the surface of the wire bonding contact area or bond areas on or on which the one or more wire bonding structures are bonded.

5 shows a die bond and wire bond arrangement 500 within the same atmosphere according to one embodiment. As in 5 shown may be the die bond and wire bond arrangement 500 have a die bond machine 502 and a wire bonder 506 which may be coupled together by means of a transport channel 504 (by which one or more dies 508 can be transported by the die bond machine 502 and the wire bonder 506 ) such that the atmosphere is so similar that oxidation of the wire bonding regions (eg comprising copper or a copper alloy) can be slowed or suppressed, thus improving copper-to-copper bonding in various embodiments. Although the atmosphere may be the same or at least similar in the die bond machine and wire bonder and transport channel, it should be noted that the process temperatures in the die bond machine 502 and in the wire bonder 506 different from each other, in other words, may be different, as described above.

6 shows a die bond and wire bond arrangement 600 , which provides a time coupling between the die bonding process and the wire process according to an embodiment. As in 6 shown may be the die bond and wire bond arrangement 600 have a die bond machine 602 and a wire bonder 606 , which can be coupled together by means of a transport mechanism 604 (by means of which one or more dies 608 ) or can be transported by the die bond machine 602 to the wire bonder 606 ), such as one or more conveyor belts, wherein one or more intermediate storage may be provided. The die bond and wire bond arrangement 600 may further comprise a controller 610 which is arranged to control the transportation of the one or more dies 608 in accordance with a predefined time-coupling (in other words for controlling the transport of the one or more dies such that the die-bonding process and the wire bonding process are performed within a rather (eg predefined) short period of time (in other words, for example, the wire bonding process may be performed be started (for example, started or stopped) at the latest within the (for example, predefined) time period after the die-bonding process 106 for example, within a time period of hours, for example, a maximum within a period of about 24 hours, for example, a maximum within a period of about 18 hours, for example, a maximum within a period of about 15 hours, for example, a maximum within a period of about 12 hours for example, within a maximum period of about 10 hours, for example, within a maximum period of about 8 hours, for example, within a maximum period of about 6 hours, for example, within a maximum period of about 4 hours, for example, within a maximum period of about 2 hours for example, within a maximum of about 1 hour or less.

In various embodiments, the die bond machine 502 . 602 and the wire bonder 506 . 606 be implemented as a common machine or as two machines arranged in a common space kept under the same atmosphere (e.g. under the same forming gas atmosphere).

Further, in various embodiments, the one or more dies may be or may be from the die-bond machine (eg, the die-bond machine 502 . 602 ) to the wire bonder (for example, the wire bonder 506 . 606 ) can be transported by means of a transport box, wherein the transport box can be arranged such that the oxidation, for example, the exposed metallic areas (for example, the Drahtbondkontaktbereiche or Drahtbondkontaktbereichs) can be slowed down or can be suppressed. In different Embodiments, the transport box may be a gas-tight box, wherein the transport box may be filled with forming gas. Further, in various embodiments, the transport box may be a vacuum box.

7 shows a cross section of a Dies 700 according to an embodiment.

The Die 700 may comprise a substrate, being on the back 704 the substrate 202 a die bond area 706 (For example, a die bonding layer 706 ) may be provided (for example, comprising or consisting of copper or a copper alloy). One or more electrical components, such as those described above, may be present in the substrate 702 be provided. The die bonding area 706 may be attached to a die bond structure 708 The-bonded. In various embodiments, the die bond structure 708 or it may be arranged as a frame structure 708 for example, as a lead frame structure 708 , The Die 700 may further comprise on its front side 710 of the substrate 702 one or more wire bond contact areas 702 which comprise copper and / or a copper alloy. In various embodiments, at least a portion of the wirebond contact region, or the wirebond contact regions may form a surface 714 Roughness of less than about 2 μm, for example a surface roughness 714 Roughness of less than about 1 μm, for example a surface roughness 714 Roughness of less than about 0.5 μm, for example a surface 714 Roughness of less than about 250 nm, for example a surface 714 Roughness of less than about 100 nm. In various embodiments, the die bond structure 708 Copper and / or a copper alloy or consist of copper and / or a copper alloy. In various embodiments, the die 700 have or be configured as a semiconductor component. In various embodiments, the die 700 have or be configured as a power semiconductor component. In various embodiments, the die 700 or be arranged as a plurality of semiconductor components. In various embodiments, the plurality of semiconductor components may comprise at least one component selected from a group of components consisting of: a memory semiconductor component; and a logic semiconductor component. In various embodiments, a wire bond structure or may include multiple wire bond structures 716 (For example, bonding wires 716 which may include or consist of copper or a copper alloy) may be wire bonded to the surface 714 one or more wire bonding contact areas 712 , In various embodiments, the surface of the one or more wire bonding contact areas may be one or more wire bonding contact areas 712 it may be free of any oxide, for example, copper oxide, or it may have only a very thin oxide layer (eg, a copper oxide layer) on the copper material, for example due to the processes described above according to various embodiments. The above-described processes according to various embodiments may thus provide a uniform surface of the one or more wire bonding contact regions 712 provide before and during or the wire bonding process (s), thereby providing a high quality electrical connection between the one wire bonding contact area and the plurality of wire bonding contact areas 712 and the one or more wire bonding structures 716 ,

8th shows a cross section of a Dies 800 according to an embodiment. The Die 800 out 8th is similar to the Die 700 out 7 , Therefore, only the differences between the 800 from 8th and the die 700 from 7 explained in more detail below. As in 8th shown, the The 800 an oxide layer 802 (For example, a copper oxide layer 802 ) on the surface 714 the respective Drahtbondkontaktbereichs 712 on. The oxide layer 802 (For example, a copper oxide layer 802 ) may be formed due to oxidation of the material (eg, copper or copper alloy) of the respective wire bonding contact area 712 , In various embodiments, the copper oxide layer may have a layer thickness of less than 100 nm, for example a layer thickness of less than 75 nm, for example a layer thickness of less than 50 nm, for example a layer thickness of less than 25 nm, for example a layer thickness of less than 10 nm ,

In various embodiments, the one or more wire bond structures may be one or more wire bond structures 716 (For example, bonding wires, which may or may consist of copper or a copper alloy) be wire bonded to the surface 714 one or more wire bonding contact areas 712 through the oxide layer 802 (for example, the one or more wire bond structures 716 through the oxide layer 802 are then pressed so that they then provide direct metal-to-metal contact (eg, copper-to-copper contact). This can result in the oxide layer 802 next to the respective wire bond structures 716 can be arranged.

9 shows a cross section of a Dies 900 according to an embodiment.

As in 9 shown in various embodiments of the die 900 have a plurality of dies that are stacked on top of or stacked one on top of the other. In general, any number of dies may be stacked on top of or above each other. The Die 900 from 9 may comprise a first power semiconductor die 902 (for example, implemented as a SiC JFET die 902 ) and a second power semiconductor die 904 (for example, implemented as an SFET die 904 ). Furthermore, in 9 for explanatory purposes, an equivalent circuit diagram 906 of the first power semiconductor dies 902 (for example, implemented as a SiC JFET die 902 ).

In various embodiments, as in 9 shown, the first power semiconductor die 902 (for example, implemented as a SiC JFET die 902 ) have a SiC substrate 908 and a drain metallization layer 910 which has a drain region of the SiC-JFET die 902 forms (as an implementation of the die bond region), for example made of AuSn. The drain metallization layer 902 can be arranged on a first page 912 (for example, the back 912 ) of the SiC substrate 908 , The SiC JFET die 902 may further include a gate region and a source region 920 , disposed on or above a titanium diffusion barrier layer 914 (For example, having a layer thickness in a range of about 100 nm to about 200 nm, for example, having a layer thickness of about 150 nm (on a second side 916 (for example, the front 916 ) of the SiC substrate 908 , opposite the first page 912 of the SiC substrate 908 , The gate area 918 and the source area 920 Both may comprise or consist of copper or a copper alloy as described above and may have a layer thickness in a range of about 1 μm to about 10 μm, for example a layer thickness in a range of about 3 μm to about 8 μm, for example one Layer thickness of about 5 microns. The first power semiconductor die 902 can be molded using molding materials 922 such as an imide, with parts of the surface 924 of the gate area 918 and parts of the surface 926 of the source area 920 remain free of molding material in other words, they remain exposed, and thus uncovered by the molding material. The exposed parts of the surface 924 of the gate area 918 and the surface 926 of the source area 920 can be purified using forming gas, similar to the various embodiments as described above. Thus, the exposed areas of the surface 924 of the gate area 918 and the surface 926 the source area 920 (after the forming gas cleaning process) have a surface roughness of less than about 2 μm, for example a surface roughness of less than about 1 μm, for example a surface roughness of less than about 0.5 μm, for example a surface roughness of less than about 250 nm For example, a surface roughness of less than about 100 nm. In various embodiments, a thin layer of copper oxide (in 9 not shown) are formed on the exposed areas of the surface 924 of the gate area 918 and the surface 926 of the source area 920 , The copper oxide layer may have a layer thickness of less than 100 nm, for example a layer thickness of less than 75 nm, for example a layer thickness of less than 50 nm, for example a layer thickness of less than 25 nm, for example a layer thickness of less than 10 nm.

In various embodiments, the drain metallization layer 910 The die-bonded or bonded to one / a frame structure, such as a lead frame structure, or to a die bond region of another die (in 9 Not shown).

The second power semiconductor die 904 may comprise a silicon substrate 928 , and a drain metallization layer 930 which has a drain region of the SFET-Dies 904 forms (as an implementation of the die bond area), for example made of AuSn or copper or a copper alloy. The drain metallization layer 930 can be arranged on a first page 932 (for example, the back 932 ) of the silicon substrate 928 , The SFET-Die 904 may further comprise a gate region 936 and a source area 938 deposited on or over a titanium diffusion barrier layer (not shown) on a second side 934 (for example, the front 934 of the silicon substrate 928 opposite the first page 932 of the silicon substrate 928 be upset. The gate area 936 and the source area 938 both may comprise or consist of copper or a copper alloy as described above, and may have a layer thickness in a range of about 1 μm to about 10 μm, for example a layer thickness in a range of 3 μm to about 8 μm, for example a layer thickness of about 5 μm. The second power semiconductor die 904 may be molded using mold material such as an imide, with areas of the surface 940 of the gate area 936 and areas of the surface 942 of the source area 938 stay free of mold material, in other words, they remain exposed. The exposed areas of the surface 940 of the gate area 936 and the surface 942 of the source area 938 can be purified using forming gas, in a similar manner as in the above-described embodiments. Thus, the exposed areas of the surface 940 of the gate area 936 and the surface 942 of the source area 938 (after the forming gas cleaning process) have a surface roughness of less than about 2 μm, for example a surface roughness of less than about 1 μm, for example a surface roughness of less than about 0.5 μm, for example a surface roughness of less than about 250 nm For example, a surface roughness of less than about 100 nm. In some embodiments, a thin oxide layer (in 9 not shown) or are formed on the exposed areas of the surface 940 of the gate area 938 and the surface 942 of the source area 938 , The copper oxide layer may have a layer thickness of less than 100 nm, for example a layer thickness of less than 75 nm, for example a layer thickness of less than 50 nm, for example a layer thickness of less than 25 nm, for example a layer thickness of less than 10 nm.

In various embodiments, the drain metallization layer 930 of the second power semiconductor dies 904 Die-bonded or attached to the exposed surface 926 of the copper-containing source region 920 of the first power semiconductor dies 902 ,

Furthermore, in various embodiments, the exposed surface 924 of the copper-containing gate region 918 of the first power semiconductor dies 902 , the exposed surface 940 of the copper-containing gate region 936 of the second power semiconductor dies 904 , as well as the exposed surface 942 of the copper-containing source region 938 of the second power semiconductor dies 904 a wire bonding process (or, in alternative embodiments, a die bonding process for die-bonding to a die bond region of another die), in other words, wire bond structures may be wire bonded to these surfaces.

In various embodiments, a die may have a plurality of dies which may be stacked on top of or stacked one upon another. Thus, in various embodiments, a die may have a multi-die arrangement (in other words a multi-chip arrangement), wherein the die bonding processes and the wire bonding processes may be provided in a similar or similar manner as described above the various embodiments with reference to the linkage of the die bonding process and the wire bonding process.

In various embodiments, die-to-die (packaging-to-die) packaging may be provided with metal-to-metal contact (eg, copper-to-copper contact) (eg, coupling of at least one or both) a plurality of copper pads with one or more copper (bond) wires (for example with a gate terminal of a FET component) with a strong time coupling between the die bonding process and the wire bonding process, so that forming gas, which is used in the context of Die Bonding process is also used for the wire bonding process.

In various embodiments, the die bonding process may be performed at a temperature (eg, at a temperature in a range of about 250 ° C to about 500 ° C, for example, a temperature in a range of about 300 ° C to about 450 ° C, for example, at a temperature in a range of about 350 ° C to about 400 ° C) for forming gas cleaning and wire bonding process may be performed at a lower, for example, a rather low, temperature (eg at a temperature in a range of about 0 ° C to about 100 ° C, for example at a temperature in a range of about 15 ° C to about 75 ° C, for example at a temperature in a range of about 20 ° C to about 50 ° C, wire bonding may be performed in various embodiments at room temperature.

In various embodiments, a combined die bonding process and wire bonding process and / or a combined die bonding and wire bonding machine may be provided.

In various embodiments, the die bonding process and the wire bonding process may be performed (in other words, they may use) in the same or the same or similar atmosphere (for example, the same or similar forming gas atmosphere).

Claims (25)

Procedure ( 200 ) for wire bonding a wirebond contact region of a die to a wirebond structure, the method comprising: • cleaning the wirebond contact region using forming gas ( 202 ); and wire bonding the wire bonding contact region to the wire bonding structure ( 204 ). Procedure ( 200 ) according to claim 1, further comprising: bonding a die bond region of the die to the die bond structure. Procedure ( 200 ) according to claim 2, wherein the die-bonding structure comprises a frame structure. Procedure ( 200 ) according to claim 3, wherein the frame structure has a lead frame structure. Procedure ( 200 ) according to one of claims 2 to 4, wherein the die-bonding structure comprises copper and / or a copper alloy. Procedure ( 200 ) according to one of claims 2 to 5, wherein the cleaning of the wire bonding contact area and the wire bonding are performed in the same atmosphere. Procedure ( 200 ) according to one of claims 2 to 6, further comprising: • providing a die-bond structure; Cleaning a part of the die bond structure which is to be die bonded to the die bond area of the die, using forming gas. Procedure ( 200 ) according to claim 7, wherein the cleaning of the part of the die bonding structure and the cleaning of the wire bonding contact area are performed in the same atmosphere. Procedure ( 200 ) according to one of claims 1 to 8, wherein the wire bonding region comprises copper and / or a copper alloy. Procedure ( 300 ) for cleaning a wire bonding contact area of a die, the method comprising: providing a die having a wire bonding contact area comprising copper and / or a copper alloy ( 302 ); and • cleaning the wire bonding contact area using forming gas ( 304 ). The ( 700 ), comprising: a wire bond contact area ( 712 ) comprising copper and / or a copper alloy, wherein at least a portion of the wire bonding contact area has a surface roughness of less than about 2 μm. The ( 700 ) according to claim 11, wherein at least a part of the wire bonding contact area ( 712 ) has a surface roughness of less than about 1 μm. The ( 700 ) according to claim 11 or 12, further comprising: • a die bond region ( 706 ); and a die bond structure ( 708 ), which are connected to the die bond area ( 706 ) of the dies ( 700 ) The-bonded. The ( 700 ) according to claim 13, wherein the die bond structure ( 708 ) has a frame structure. The ( 700 ) according to claim 13 or 14, wherein the die bond structure ( 708 ) Comprises copper and / or a copper alloy. The ( 700 ) according to one of claims 11 to 15, further comprising: a semiconductor component. The ( 700 ) according to claim 16, wherein the semiconductor component comprises a power semiconductor component. The ( 800 ) comprising: a wire bond contact area ( 712 ) comprising copper and / or a copper alloy, wherein a part of the wire bonding contact region ( 712 ) is oxidized, • whereby a copper oxide layer ( 802 ) is formed; Where the copper oxide layer ( 802 ) has a layer thickness of less than 100 nm. The ( 800 ) according to claim 18, further comprising: a wire bonding structure ( 716 ), bonded to the wire bond contact area ( 712 ); Where the copper oxide layer ( 802 ) next to the wire bond structure ( 716 ) is arranged. The ( 800 ) according to claim 18 or 19, further comprising: • a die bond region ( 706 ); and a die bond structure ( 708 ), Die-bonded to the die bond region ( 706 ) of the dies ( 800 ) The ( 800 ) according to claim 20, wherein the die bond structure ( 708 ) has a frame structure. The ( 800 ) according to claim 20 or 21, wherein the die bond structure ( 708 ) Comprises copper and / or a copper alloy. The ( 800 ) according to one of claims 18 to 22, further comprising: a semiconductor component. The ( 800 ) according to claim 23, wherein the semiconductor component comprises a power semiconductor component. The ( 800 ) according to one of claims 18 to 24, comprising: a plurality of semiconductor components.

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