Improved under bump metallization structures and associated methods of formation

Abstract

The disclosure relates to improved under bump metallization structures and associated methods of formation. Methods, systems, and devices for semiconductor fabrication are described. One such method includes forming a first layer comprising a first material. A top surface of the first layer extends along a first direction and a second direction. In some cases, the method includes forming a second layer comprising a second material on a top surface of at least the first layer, and forming voids in the second layer. Forming the void may expose a portion of the top surface of the first layer. In some cases, the method may include forming one or more layers on a top surface of the second layer and on exposed portions of a top surface of the first layer. The method may also include performing a material removal operation that lifts portions of the one or more layers formed on a top surface of the second layer away from the top surface.

Description

Technical Field

[0001] Example embodiments of the present disclosure generally relate to semiconductor devices and manufacturing techniques. More specifically, the present disclosure relates to improved under bump metallization structures and associated formation methods. Background Art

[0002] Some semiconductor devices may include layers of various materials formed in a stack above a semiconductor substrate. Such semiconductor devices may be formed using various techniques, such as photolithography, etching, deposition, doping, and other techniques. These techniques may be used to form patterns with various materials and configurations that enable the semiconductor device to operate. In some cases, a semiconductor device may include various structures for coupling with other devices, such as other semiconductor devices. For example, a semiconductor device may include one or more layers formed in a manner that the semiconductor device can be coupled to another semiconductor device (e.g., via soldering, via flip chip bonding). Summary of the invention

[0003] Various embodiments described herein relate to methods, apparatus, and systems associated with improved under bump metallization structures. In one aspect, a method includes forming a first layer comprising a first material, wherein a top surface of the first layer extends along a first direction and a second direction, the first direction being parallel to a width of the first layer and the second direction being parallel to a depth of the first layer, forming a second layer comprising a second material on at least the top surface of the first layer, forming a void in the second layer, wherein forming the void exposes a portion of the top surface of the first layer, forming one or more layers on the top surface of the second layer and on the exposed portion of the top surface of the first layer, and performing a material removal operation, wherein the material removal operation lifts portions of the one or more layers formed on the top surface of the second layer off the top surface.

[0004] In some cases, forming the one or more layers includes: forming a third layer comprising a third material on the top surface of the second layer and on the exposed portion of the top surface of the first layer, forming a fourth layer comprising a fourth material on the top surface of the third layer, and forming a fifth layer comprising a fifth material on the top surface of the fourth layer. In some cases, performing the material removal operation may include removing the portion of the one or more layers using an adhesive film. The method may also include forming a sixth material on the top layer of the one or more layers, wherein forming the sixth material avoids forming the sixth material in contact with the second layer. The method may also include forming a sixth layer comprising the second material, wherein the first layer is formed on the sixth layer.

[0005] The method may also include performing a reflow operation, wherein the reflow operation is performed to couple the first layer to the device via at least the one or more layers. The method may also include forming a column comprising a seventh material on the top layer of the one or more layers, wherein the height axis of the column extends along a third direction parallel to the height of the first layer, and forming a seventh layer comprising a fourth material on the top surface of the column. In some cases, the one or more layers include under-bump metallization. Other technical features are obvious and easy to think of for those skilled in the art based on the subsequent drawings, descriptions and claims.

[0006] In some cases, the first material may be aluminum, the second material may be silicon nitride, the third material may be titanium, the fourth material may be nickel, and the fifth material may be silver. In some cases, the height dimension of the fourth layer may be greater than or equal to 300 nanometers. In some cases, the sixth material may include a solder material.

[0007] In one aspect, a device includes: a first layer comprising a first material, wherein the first layer has a width parallel to a first direction, a depth parallel to a second direction, and a height parallel to a third direction; a second layer comprising a second material, formed on at least a top surface of the first layer, the top surface of the first layer extending along the first direction and the second direction; a void formed in the second layer, wherein the range of the void includes a sidewall of the second layer and a portion of the top surface of the first layer, wherein the sidewall of the second layer is parallel to the third direction; and one or more layers, formed on the sidewall of the second layer and the portion of the top surface of the first layer, the one or more layers being used to couple the first layer with a bonding material. In some cases, the one or more layers may include a third layer comprising a third material, the third layer being formed on the top surface of the second layer; a fourth layer may include a fourth material, the fourth layer being formed on the top surface of the third layer, and a fifth layer may include a fifth material, the fifth layer being formed on the top surface of the fourth layer. In some cases, the bonding material may include solder.

[0008] The device may also include: a sixth layer comprising the second material, wherein the first layer is formed on the sixth layer. The device may also include a column comprising a seventh material, wherein the height axis of the column extends along a third direction, and a seventh layer comprising the fourth material, the seventh layer being formed on the top surface of the column. In some cases, the one or more layers may include under-bump metallization. Other technical features are obvious and easy to think of for those skilled in the art based on the following drawings, descriptions and claims.

[0009] In some cases, the first material may be aluminum, the second material may be silicon nitride, the third material may be titanium, the fourth material may be nickel, and the fifth material may be silver. In some cases, the height dimension of the fourth layer may be greater than or equal to 300 nanometers. In some cases, the sixth material may include a solder material.

[0010] In one aspect, a product may be formed by a method comprising: forming a first layer comprising a first material, wherein a top surface of the first layer extends along a first direction and a second direction, the first direction being parallel to a width of the first layer and the second direction being parallel to a depth of the first layer; forming a second layer comprising a second material on at least the top surface of the first layer; forming a void in the second layer, wherein the formation of the void exposes a portion of the top surface of the first layer; forming one or more layers on the top surface of the second layer and on the exposed portion of the top surface of the first layer; and performing a material removal operation, wherein the material removal operation lifts (e.g., removes) portions of the one or more layers formed on the top surface of the second layer off of (e.g., removing) the top surface.

[0011] In some cases, forming one or more layers includes: forming a third layer comprising a third material on a top surface of the second layer and on an exposed portion of a top surface of the first layer; forming a fourth layer comprising a fourth material on a top surface of the third layer; and forming a fifth layer comprising a fifth material on a top surface of the fourth layer. In some cases, performing a material removal operation may include removing the portion of the one or more layers using an adhesive film. The method for forming a product may also include forming a sixth material on a top layer of the one or more layers, wherein forming the sixth material avoids forming the sixth material in contact with the second layer. The method for forming a product may also include forming a sixth layer comprising a second material, wherein the first layer is formed on the sixth layer.

[0012] The method for forming a product may also include performing a reflow operation, wherein the reflow operation is performed to couple the first layer to the device via at least the one or more layers. The method for forming a product may also include forming a column comprising a seventh material on the top layer of the one or more layers, wherein the height axis of the column extends along a third direction parallel to the height of the first layer, and forming a seventh layer comprising a fourth material on the top surface of the column. In some cases, the one or more layers include under-bump metallization. According to the following drawings, descriptions and claims, other technical features are obvious and easy to think of for those skilled in the art.

[0013] In some cases, the first material may be aluminum, the second material may be silicon nitride, the third material may be titanium, the fourth material may be nickel, and the fifth material may be silver. In some cases, the height dimension of the fourth layer may be greater than or equal to 300 nanometers. In some cases, the sixth material may include a solder material.

[0014] In one aspect, a non-transitory computer-readable storage medium may include instructions that, when executed by a computer, cause the computer to: form a first layer comprising a first material, wherein a top surface of the first layer extends along a first direction and a second direction, the first direction being parallel to a width of the first layer and the second direction being parallel to a depth of the first layer, form a second layer comprising a second material on at least the top surface of the first layer, form a void in the second layer, wherein forming the void exposes a portion of the top surface of the first layer, form one or more layers on the top surface of the second layer and on the exposed portion of the top surface of the first layer, and perform a material removal operation, wherein the material removal operation lifts portions of the one or more layers formed on the top surface of the second layer off the top surface.

[0015] In some cases, forming the one or more layers includes: forming a third layer comprising a third material on the top surface of the second layer and on the exposed portion of the top surface of the first layer, forming a fourth layer comprising a fourth material on the top surface of the third layer, and forming a fifth layer comprising a fifth material on the top surface of the fourth layer. In some cases, performing the material removal operation may include removing the portion of the one or more layers using an adhesive film. The instructions executed by the computer may also cause the computer to form a sixth material on the top layer of the one or more layers, wherein forming the sixth material avoids forming the sixth material in contact with the second layer. The instructions executed by the computer may also cause the computer to form a sixth layer comprising the second material, wherein the first layer is formed on the sixth layer.

[0016] The instructions executed by the computer may also cause the computer to perform a reflow operation, wherein the reflow operation is performed to couple the first layer to the device via at least the one or more layers. The instructions executed by the computer may also cause the computer to form a column comprising a seventh material on the top layer of the one or more layers, wherein the height axis of the column extends along a third direction parallel to the height of the first layer, and form a seventh layer comprising a fourth material on the top surface of the column. In some cases, the one or more layers include under-bump metallization. Other technical features are obvious and easy to think of for those skilled in the art based on the following drawings, descriptions and claims.

[0017] In one aspect, a computing device includes a processor. The computing device also includes a memory storing instructions that, when executed by the processor, configure the device to: form a first layer comprising a first material, wherein a top surface of the first layer extends along a first direction and a second direction, the first direction being parallel to a width of the first layer and the second direction being parallel to a depth of the first layer, form a second layer comprising a second material on at least the top surface of the first layer, form a void in the second layer, wherein forming the void exposes a portion of the top surface of the first layer, form one or more layers on the top surface of the second layer and on the exposed portion of the top surface of the first layer, and perform a material removal operation, wherein the material removal operation lifts portions of the one or more layers formed on the top surface of the second layer off the top surface.

[0018] In some cases, forming the one or more layers includes: forming a third layer including a third material on the top surface of the second layer and on an exposed portion of the top surface of the first layer, forming a fourth layer including a fourth material on the top surface of the third layer, and forming a fifth layer including a fifth material on the top surface of the fourth layer.

[0019] In some cases, performing the material removal operation includes removing a portion of the one or more layers using an adhesive film. The instructions may also configure the apparatus to form a sixth material on a top layer of the one or more layers, wherein forming the sixth material avoids forming the sixth material in contact with the second layer. The instructions may also configure the apparatus to form a sixth layer comprising the second material, wherein the first layer is formed on the sixth layer.

[0020] In some cases, the instructions further configure the device to perform a reflow operation, wherein the reflow operation is performed to couple the first layer to the device via at least the one or more layers. The instructions may further configure the device to: form a column comprising a seventh material on the top layer of the one or more layers, wherein the height axis of the column extends along a third direction parallel to the height of the first layer, and form a seventh layer comprising a fourth material on the top surface of the column. In some cases, the one or more layers can be examples of under-bump metallization. Based on the following drawings, descriptions, and claims, other technical features are obvious and easy to think of for those skilled in the art.

[0021] In some cases, the first material may be aluminum, the second material may be silicon nitride, the third material may be titanium, the fourth material may be nickel, and the fifth material may be silver. In some cases, the height dimension of the fourth layer may be greater than or equal to 300 nanometers. In some cases, the sixth material may include a solder material.

[0022] The above illustrative summary and other exemplary objects and / or advantages of the present disclosure, and the manner in which the same are achieved, will be further explained in the following detailed description and its accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The description of the illustrative embodiments may be read in conjunction with the accompanying drawings. It should be understood that, for simplicity and clarity of illustration, the elements shown in the drawings are not necessarily drawn to scale unless otherwise described. For example, the dimensions of some elements may be exaggerated relative to other elements unless otherwise described. Embodiments incorporating the teachings of the present disclosure are shown and described in conjunction with the accompanying drawings set forth herein, in which:

[0024] Figure 1 illustrates examples of material arrangements supporting improved under bump metallization structures and associated formation methods;

[0025] Figure 2 illustrates examples of regions supporting improved under bump metallization structures and associated formation methods;

[0026] Figure 3 An example of a process flow supporting an improved under bump metallization structure and associated formation method is illustrated;

[0027] Figure 4A and Figure 4B illustrates examples of material arrangements supporting improved under bump metallization structures and associated formation methods;

[0028] Figure 5A and Figure 5B illustrates examples of material arrangements supporting improved under bump metallization structures and associated formation methods;

[0029] Figure 6 An example of a flow chart illustrating an improved under bump metallization structure and associated formation method is shown; and

[0030] Figure 7 An example of a flow chart supporting an improved under bump metallization structure and associated formation method is shown. DETAILED DESCRIPTION

[0031] Some embodiments of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which some but not all embodiments of the present disclosure are shown. Indeed, these disclosures may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present disclosure will satisfy applicable legal requirements. The same reference numerals indicate the same elements throughout.

[0032] As used herein, terms such as "front," "rear," "top," and the like are used for explanation purposes in the examples provided below to describe the relative positions of certain components or portions of components. Additionally, as will be apparent to one of ordinary skill in the art from this disclosure, the terms "substantially" and "approximately" indicate that the referenced item or associated description is accurate within applicable engineering tolerances.

[0033] As used herein, the term "comprising" means including but not limited to, and should be interpreted in the manner commonly used in the patent context. The use of broader terms such as including, comprising, and having should be understood to provide support for narrower terms such as consisting of, consisting substantially of, and consisting essentially of.

[0034] The phrases "in one embodiment," "according to an embodiment," and the like generally mean that the particular feature, structure, or characteristic following the phrase may be included in at least one embodiment of the present disclosure, and may be included in more than one embodiment of the present disclosure (importantly, these phrases do not necessarily refer to the same embodiment).

[0035] The word “example” or “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other implementations.

[0036] If the specification states that a component or feature "may", "can", "might", "should", "would", "preferably", "likely", "usually", "optionally", "for example", "often", or "might" (or other such language) be included or have a property, it is not required that the particular component or feature be included or have that property. Such components or features may optionally be included in some embodiments, or may be excluded.

[0037] Figure 1An example of a material arrangement 100 that supports an improved under-bump metallization structure and an associated formation method is illustrated. In some cases, the material arrangement 100 may be an example of a portion of a semiconductor device or any other electronic device. The material arrangement 100 may be a device or a portion of a device employed in various applications such as automotive applications (e.g., for motor control, for charging modules). The material arrangement 100 may illustrate a cross-sectional view of a semiconductor device, in which some portions of the semiconductor device may be truncated or not shown. The material arrangement 100 may include one or more layers 105, which may each correspond to one or more materials 110. Although some examples of specific materials 110 or combinations of materials 110 (e.g., compounds, mixtures, composites) are described herein, the material arrangement 100 may include any combination of materials 110.

[0038] As described herein, the material arrangement 100 may be an example of a power device or a portion of a power device. For example, the material arrangement 100 may be an example of a transistor (e.g., a power transistor) or a diode (e.g., a power diode, a thin diode). Such a power device may be able to handle relatively high currents and relatively high voltages compared to other devices. In some cases, the material arrangement 100 may be an example of a power device (e.g., a transistor, a diode) included in a charging module of an electric vehicle. Additionally or alternatively, the material arrangement 100 may be an example of a power device (e.g., a transistor, a diode) included in a motor control module of an electric vehicle. In some cases, the material arrangement 100 may be an example of a bipolar junction transistor (BJT), a field effect transistor (FET), a metal oxide semiconductor field effect transistor (MOSFET), an insulated gate bipolar transistor (IGBT), a thyristor, or a silicon controlled rectifier (SCR).

[0039] In an illustrative example, material arrangement 100 may include six layers 105, although any number of layers 105 may be used. Material arrangement 100 may include layer 105-a (e.g., solder layer), layer 105-b (e.g., intermetallic compound (IMC) layer, layer including at least silver), layer 105-c (e.g., nickel layer), layer 105-d (e.g., titanium layer), layer 105-e (e.g., aluminum layer), and layer 105-f (e.g., yttrium-silicon-nitride layer). Each layer 105 may be formed in contact with one or more other layers 105. In some cases, layer 105-f may be an example of a passivation layer, and other layers 105 may be formed on top of or in contact with the passivation layer. For example, layer 105-e may be formed on top of layer 105-f or partially within layer 105-f. In some cases, one or more of layers 105 may be formed as part of a metallization operation (eg, final metallization may be performed using TiNiAg).

[0040] Layer 105-a may be formed using material 110-a. Material 110-a may be an example of a conductive material, such as solder (e.g., a solder alloy). In some cases, material 110-a may be a tin-lead alloy, a tin-silver alloy, a tin-silver-copper alloy, a tin-copper alloy, or any other alloy. Layer 105-b may be formed using material 110-b. In some cases, material 110-b may be an example of a gold-aluminum alloy, a gold-germanium alloy, a nickel-germanium alloy, a palladium-silicon alloy, or any other alloy. Layer 105-c may be formed using material 110-c. Material 110-c may be an example of nickel or any other conductive material. Layer 105-d may be formed using material 110-d. Material 110-d may be an example of titanium or any other conductive material. Layer 105-e may be formed using material 110-e. Material 110-e may be an example of aluminum, aluminum-copper, or any other conductive material. Layer 105-f may be formed using material 110-f. Material 110 - f may be examples of silicon nitride, yttrium silicon nitride, silicon dioxide, polyimide, or any other passivation material.

[0041] One or more layers in layer 105 may be included in under-bump metallization (UBM) 115, which may be referred to as a UBM layer in some cases. For example, UBM 115 may include layer 105-b, layer 105-c, and layer 105-d. In some cases, UBM 115 may electrically couple layer 105-a with layer 105-e. As described herein, forming UBM 115 may include one or more operations. For example, one or more deposition operations and one or more etching operations (e.g., one or more wet etching operations) may be performed to form UBM 115. UBM 115 may be formed on a surface (e.g., top surface) of layer 105-e and on one or more surfaces of layer 105-f. For example, UBM 115 may be deposited on the horizontal and vertical surfaces of layer 105-f, and formed on the horizontal surface of layer 105-e. As described herein, a vertical surface may refer to a surface occupying a yz plane, an xy plane, or any other plane perpendicular to the xz plane. A horizontal surface may refer to a surface occupying an xz plane. The vertical and horizontal surfaces as described herein may also be curved or irregular. It should also be understood that the material arrangement 100 may illustrate a cross-section of a semiconductor device. Thus, the material arrangement 100 may include three-dimensional features such as cylinders, spheres, cuboids, or other irregular three-dimensional features. As an illustrative example, a void (e.g., a cylindrical void, a cuboid void) may be formed in the layer 105-f, and the UBM 115 may be formed on the vertical surface of the layer 105-f produced by the formation of the void.

[0042] In some cases, one or more operations may be used to form the material arrangement 100, such as photolithography, etching, deposition, doping, metallization, soldering, or any other type of operation. In some cases, layer 105-e may be deposited on layer 105-f, layer 105-d may be deposited on 105-e, and layer 105-c may be deposited on 105-d. Although not shown, an additional layer 105 (e.g., a silver layer) may be deposited on layer 105-c and melted during the soldering operation. That is, the additional layer 105 may be an example of one or more components of layer 105-b. As described herein, the material arrangement 100 may illustrate a stack of materials including one or more layers 105, which have been subjected to a soldering operation or any other type of operation that results in the formation of layer 105-b (e.g., an intermetallic compound). Layer 105-b may be an example of a compound or mixture of one or more materials. For example, layer 105-b may contain solder, silver, nickel, or any other combination of materials.

[0043] In some cases, material arrangement 100 can include one or more layers 105 for coupling layer 105-e (e.g., a redistribution layer) with circuitry of one or more other devices, such as another semiconductor device (not shown). For example, layer 105-d, layer 105-c, and at least a portion of layer 105-b can be examples of UBM 115, which can refer to a conductive portion of a semiconductor device located below a solder bump (e.g., layer 105-a). In some cases, material arrangement 100 can be one example of multiple material arrangements 100 for a semiconductor device.

[0044] The material arrangement 100 may include one or more regions 120 (eg, region 120-a, region 120-b, region 120-c), some of which may be referred to as Figure 2 Further detailed description. Region 120-a may illustrate a central region of material arrangement 100 (e.g., of a semiconductor device). Region 120-a may include layer 105-f, layer 105-e, layer 105-d, layer 105-c, layer 105-b, and a portion of layer 105-a. Region 120-b may illustrate a corner region of material arrangement 100. For example, region 120b may include a portion of UBM 115 located in a corner formed by layer 105-e and layer 105-f. Region 120-b may show a relatively thin portion of UBM 115 (when compared to other portions of UBM 115). For example, due to challenges associated with forming UBM 115 in a corner, a cavity (e.g., a crack, a fracture) may be formed in one or more layers 105 of UBM 115. Region 120-c may be an example of a peripheral or edge region of material arrangement 100. Region 120 - c may include one or more edges or regions of layer 105 included in UBM 115 .

[0045] Some techniques used to form the material arrangement 100 may be associated with various challenges. For example, a physical vapor deposition (PVD) process may be used to form the UBM 115, which may bring some challenges associated with uniformly depositing materials in the presence of certain geometries (e.g., corners). Referring to the material arrangement 100, the layer 105-e and the layer 105-f may form a corner. As a result, the various layers 105 of the UBM 115 may not be uniformly formed (e.g., voids or cracks may be formed through one or more layers 105 of the UBM 115, and the UBM 115 may be thinned). As a result, the corner area of ​​the UBM 115 may be affected by current crowding, or may be affected by a lack of effective cooling, which may lead to failure.

[0046] Some other reliability challenges may be associated with forming the UBM 115 in the region 120-c (e.g., the edge region of the material arrangement 100). For example, some embodiments of the PVD process or the associated etching process may result in the formation of an overhanging layer 105 (e.g., layer 105-c may extend beyond layer 105-d with respect to the x-direction), which may result in mechanical stress (e.g., when a solder bump is formed on the overhanging layer 105). In this case, the mechanical stress may be exacerbated by the increased thickness (e.g., along the y-direction) of the layer 105 (such as layer 105-c). Additionally, or alternatively, the bonding or adhesion between the metallic material and the polymer layer (e.g., layer 105-d and layer 105-f) may be relatively weak compared to the adhesion between similar materials (e.g., between two metals), which may result in delamination. Delamination may also be caused by differences in the respective coefficients of thermal expansion between layers 105, or by residues (eg, carbon residues) on the surface of layer 105-f (eg, if the photoresist was not stripped properly).

[0047] The present disclosure provides methods for effectively removing portions of the UBM 115 that are associated with or otherwise cause reliability challenges as described above, for example, a portion of the UBM 115 formed on the layer 105-f may be lifted off using tape. In this case, the UBM 115 may break (e.g., split) at a crack formed in the UBM 115 or at or near a thin area of ​​the UBM 115 (e.g., at or near a corner formed by the layer 105-f and the layer 105-e). Such removal of portions of the UBM 115 may be enabled or assisted by various structural instabilities associated with the UBM 115. For example, a crack (e.g., a void) formed in the UBM 115 in a sharp corner may result in a relatively weak area that is susceptible to device fracture during the lift-off process. Additionally, or alternatively, a relatively weak bond between the layer 105-f and the layer 105-d (e.g., the bottom layer of the UBM 115) may result in delamination that enables lift-off. In some cases, all portions of UBM 115 that are in contact with layer 105-f may be removed. However, in some other cases, some portions of UBM 115 formed on a vertical surface of layer 105-f (e.g., in region 120-b) may not be removed. For example, UBM 115 may be broken in a region located above a corner relative to the y-direction.

[0048] In some cases, one or more processing steps that would otherwise increase adhesion between layer 105-f and layer 105-d (e.g., the bottom layer of UBM 115) may not be performed, which may increase processing speed and reduce processing costs. For example, one or more processing steps to remove carbon residues from the surface of layer 105-f prior to forming layer 105-d may be skipped, thereby reducing adhesion of layer 105-d to layer 105-f and enabling more efficient removal of portions of UBM 115 formed on the surface of layer 105-f. In addition, the techniques described herein may enable a reduction in the size of layer 105-a (e.g., the diameter of a solder bump), which may reduce consumption of material 110-a and may improve space utilization.

[0049] Figure 2 An example of a region 120 that supports an improved under bump metallization structure and associated formation method is shown. The region 120 (eg, region 120-b, region 120-c) may be as described in reference Figure 1 Examples of various regions 120 described herein. For example, region 120 may illustrate a portion of material arrangement 100, which may be an example of a semiconductor device or a portion of a semiconductor device. Region 120 may also illustrate different configurations of a thickness 205 (e.g., height) of layer 105-c (e.g., a nickel layer). For example, as shown in region 120-b-1, layer 105-c may have a thickness 205-a, and as shown in region 120-b-2, layer 105-c may have a thickness 205-b that is greater than thickness 205-a. Similarly, as shown in region 120-c-1, layer 105-c may have a thickness 205-a, and as shown in region 120-c-2, layer 105-c may have a thickness 205-b. According to the examples described herein, Figure 2 As shown in , increasing the thickness 205 of layer 105 - c may exacerbate various challenges.

[0050] Each region 120 may illustrate one or more layers 105 of the material arrangement 100. For example, each region 120 may include a layer 105-g (e.g., a silver layer), a layer 105-c (e.g., a nickel layer), a layer 105-d (e.g., a titanium layer), a layer 105-e (e.g., an aluminum layer), and a layer 105-f (e.g., a silicon nitride layer). Each layer 105 may be formed in contact with one or more other layers 105. In some cases, layer 105-f may be an example of a passivation layer. Layer 105-c may be formed using material 110-c. Material 110-c may be an example of nickel or any other conductive material. Layer 105-d may be formed using material 110-d. Material 110-d may be an example of titanium or any other conductive material. Layer 105-e may be formed using material 110-e. Material 110-e may be an example of aluminum, aluminum copper, or any other conductive material. Layer 105-f may be formed using material 110-f. Material 110-f may be examples of silicon nitride, yttrium silicon nitride, silicon dioxide, polyimide, or any other passivation material. Material 110-g may be used to form layer 105-g. Material 110-g may be examples of silver or any other conductive material.

[0051] One or more layers of layer 105 may be included in UBM 115. For example, UBM 115 may include layer 105-g, layer 105-c, and layer 105-d. As described herein, forming UBM 115 may include one or more operations. For example, one or more etching operations (e.g., one or more wet etching operations) may be performed to form UBM 115. UBM 115 may be formed on a surface (e.g., a top surface) of layer 105-e and one or more surfaces of layer 105-f. For example, UBM 115 may be deposited on both horizontal and vertical surfaces of layer 105-f, as well as on horizontal surfaces of layer 105-e.

[0052] Some customers may request an increase in the thickness 205 of layer 105-c (e.g., up to 2.6 microns (μm)). However, in some cases, increasing the thickness 205 of layer 105-c may increase various stresses and reduce the extent to which the passivation material (e.g., layer 105-f) can cover layer 105-c. In some cases, the thickness of layer 105-c may range between 300 nanometers (nm) and 2.6 μm. A typical thickness of layer 105-d may be 200nm, and a typical thickness of layer 105-g may be 800nm. In some cases, layer 105 of UBM 115 may be formed using a spray wet etching operation, which may enable one or more undercuts to be formed, as shown in region 120-c. For example, one or more spray wet etching operations may be used to remove material from layer 105-d, layer 105-c, layer 105-g, or any combination thereof. In some cases, removing material from layer 105 may form an undercut region. For example, the extent of layer 105-c in the x-direction may be greater than the extent of layer 105-d in the x-direction. In some cases, the formation of undercuts or overhangs may cause or exacerbate mechanical stresses between layers 105. Additionally or alternatively, an increase in the thickness of layer 105-c may cause or exacerbate mechanical stresses between layers 105. As shown in region 120-c-2, delamination may occur between layer 105-d and layer 105-f. Such delamination may occur if thickness 205-b meets a threshold (e.g., is greater than or equal to a threshold).

[0053] The layer 105 of the material arrangement 100 can be formed to have a changed degree of conformality. For example, when compared with the layer 105-c and the layer 105-g, the layer 105-d can be relatively conformal. Therefore, the layer 105-d can easily conform to the geometry of the layer 105-f and the layer 105-e. However, the layer 105-c and the layer 105-g may not conform to the geometry of the layer 105-d. That is, thinning (e.g., stacked thinning) may occur in the layer 105-c and the layer 105-g (e.g., at the corner area). When compared with the part of the layer 105 formed away from the corner area, this thinning may cause the layer 105-g and the layer 105-c to have a reduced thickness in the corner area. In some cases, the thinned area of ​​the layer 105-g and the layer 105-c can be referred to as a gap or crack. In some cases, the thinning of the layer 105-g and the layer 105-c may have a negative electrical effect. For example, thinned areas may generate harmonics or present other challenges associated with high frequency electrical signals. In some cases, as described herein, increasing the thickness 205 of layer 105-c may increase the degree to which layers 105-c and 105-g are thinned (e.g., in corner areas). Thus, region 120-b-2 illustrates a greater degree of thinning of layers 105-g and 105-c than region 120-b-1.

[0054] The present disclosure provides methods for forming UBM 115 that enable increasing the thickness 205 of layer 105-c without adverse effects (e.g., without delamination). For example, the techniques described herein may include removing portions of UBM 115 that may otherwise delaminate. For such material removal operations, thinned regions of UBM 115 may increase ease of removal. For example, regions of UBM 115 formed on horizontal surfaces (e.g., extending along the x-direction and the z-direction) of layer 105-f may be lifted off of layer 105-f (e.g., using an adhesive), which may cause UBM 115 to fracture at or near the thinned regions.

[0055] In some cases, one or more processing steps that would otherwise increase adhesion between layer 105-f and layer 105-d (e.g., the bottom layer of UBM 115) may not be performed, which may increase processing speed and reduce processing costs. For example, one or more processing steps to remove carbon residue from the surface of layer 105-f prior to forming layer 105-d may be skipped, thereby reducing adhesion of layer 105-d to layer 105-f and enabling more efficient removal of portions of UBM 115 formed on the surface of layer 105-f.

[0056] Figure 3 An example of a process flow 300 that supports an improved under bump metallization structure and associated formation methods is illustrated. The process flow 300 may be used to form a substrate such as a substrate shown in FIG. Figure 1 An example of one or more manufacturing operations (e.g., one or more steps 305) of a material arrangement 100 (e.g., a semiconductor device) is described. The process flow 300 can be performed by one or more machines or other manufacturing equipment that are configured to perform the one or more steps 305 described herein. The machine configured to perform the steps 305 described herein may include a controller, a processor, or any other computing device that can execute code to perform the one or more steps 305. As described herein, the process flow 300 may include one or more steps 305 for forming one or more layers 105 and UBM 115. The one or more layers 105 and UBM 115 may be as described in reference Figure 1 and Figure 2 Examples of respective layers 105 and UBM 115 are described.

[0057] The process flow 300 may include one or more steps 305 (e.g., one or more operations) that may be performed in the order shown or in a different order. In some cases, one or more steps 305 may be omitted from the process flow 300. In addition, the process flow 300 may illustrate different options for performing the steps 305 described herein. In one example, the process flow 300 may include performing a first set of steps (e.g., step 305-a, step 305-b, step 305-c, step 305-d-1, step 305-e-1, and step 305-f-1). In another example, the process flow 300 may include performing a second set of steps (e.g., step 305-a, step 305-b, step 305-c, step 305-d-2, step 305-e-2, and step 305-f-2). In some cases, the second set of one or more steps 305 may result in one or more processing improvements when compared to the first set of one or more corresponding steps 305. For example, performing the second set of one or more steps 305 may result in improved strength, reduced material costs, increased processing speeds, and reduced environmental impact (e.g., by reducing the use of one or more chemicals) of material arrangement 100. In some cases, the improved strength of material arrangement 100 may enable one or more layers 105 (e.g., a nickel layer) to be formed with an increased thickness, which may be desirable for some use cases.

[0058] At step 305-a, one or more photolithography operations, one or more etching operations (e.g., aluminum etching operations), and one or more stripping operations (e.g., photoresist stripping operations) may be performed. Step 305-a may be an example of a metal redistribution layer formation operation (e.g., for forming layer 105-e). Step 305-a may include forming layer 105-h (e.g., photoresist). Layer 105-h may be formed using material 110-h. Material 110-h may be an example of a photoresist material, such as a polymer material that is sensitive to ultraviolet (UV) light. In some cases, a pattern may be formed in layer 105-h by exposing layer 105-h to UV light filtered through a mask. Once the pattern is formed in layer 105-h, one or more etching operations may be performed to selectively remove portions of layer 105-e (e.g., portions of layer 105-e that are not covered or not in contact with layer 105-h). Although Figure 3 The middle layer 105-h is shown as being continuous, but the layer 105-h may include one or more voids or one or more areas that expose the surface of the layer 105-e. Step 305-a may also include one or more operations to strip the layer 105-h (e.g., after the layer 105-e has been etched).

[0059] At step 305-b, one or more deposition operations (e.g., a passivation deposition operation), one or more photolithography operations, one or more etching operations (e.g., a passivation etching operation), and one or more stripping operations (e.g., one or more photoresist stripping operations) may be performed. Step 305-b may be an example of a passivation layer forming operation (e.g., for forming layer 105-f-2). In some cases, step 305-b may include forming one or more portions of layer 105-f-2. For example, one or more portions of material 110-f may be formed on a surface of layer 105-f-1 and on a surface of layer 105-e, thereby forming a portion of layer 105-f-2 as shown. Step 305-b may also include forming layer 105-h-1 and forming layer 105-h-2. Layer 105-h-1 and layer 105-h-2 may be formed using material 110-h. In some cases, layer 105-f-2 may be formed using an etching operation to selectively remove portions of layer 105-f-2 that are not in contact with layer 105-h-1 or layer 105-h-2. Step 305-b may also include performing one or more operations to remove layer 105-h-1 and layer 105-h-2.

[0060] At step 305-c, one or more deposition operations (e.g., UBM 115-a deposition operations) may be performed. In some cases, the one or more deposition operations may include one or more physical vapor deposition (PVD) operations. For example, one or more PVD operations may be used to form UBM 115-a. As shown, UBM 115-a may be formed on the surface of layer 105-f-2 and layer 105-e. UBM 115-a may be thinned in a corner region (e.g., a region where layer 105-f-2 and layer 105-e form a sharp corner). In this case, the thinned region of UBM 115-a may be relatively weak compared to other regions of UBM 115-a.

[0061] At step 305-d-1, one or more photolithography operations, one or more etching operations (e.g., wet etching operations), and one or more stripping operations (e.g., photoresist stripping operations) may be performed. For example, step 305-d-1 may include forming layer 105-h-3. Layer 105-h-3 may be formed using material 110-h. Layer 105-h-3 may be an example of a photoresist for forming a region of UBM 115-e. For example, one or more etching operations may be performed to selectively remove edge regions of UBM 115-a so that UBM 115-e is formed. UBM 115-e may include one or more overhanging portions, which may result in a reduction in the strength of UBM 115-e or a tendency for UBM 115-e to delaminate from layer 105-f-2. After performing the one or more etching operations, layer 105-h-3 may be removed (e.g., using a photoresist stripping operation).

[0062] Additionally, step 305-d-1 can include placing the material arrangement 100 on an adhesive film (e.g., tape) for a grinding operation, performing the grinding operation, and removing the adhesive film. Specifically, the adhesive film can be placed on one or more surfaces of the UBM 115-e. The adhesive film can be used to secure the material arrangement 100 while performing the grinding operation. The grinding operation can include grinding a bottom surface (e.g., with respect to the y-direction) of the layer 105-f-2 (e.g., to flatten the surface or otherwise prepare the surface for forming the layer 105-j).

[0063] At step 305-e-1, one or more etching operations (e.g., spin etching operations) and one or more deposition operations (e.g., one or more PVD operations) may be performed. In some cases, the one or more deposition operations may include forming layer 105-j (e.g., on a rough surface of layer 105-f-2, on a polished surface of layer 105-f-2). Layer 105-j may be formed using material 110-j. In some cases, material 110-j may be a composite or compound including one or more materials 110. For example, although shown as a single layer 105, layer 105-j may include one or more layers formed using one or more materials. In an illustrative example, layer 105-j may include a titanium layer, a nickel layer, and a silver layer. A titanium layer may be formed on the surface of layer 105-f-2, a nickel layer may be formed on the surface of the titanium layer, and a silver layer may be formed on the surface of the nickel layer.

[0064] At step 305-f-1, one or more dicing operations and one or more bumping operations may be performed. The one or more dicing operations may include slicing or cutting the material arrangement 100 into a plurality of semiconductor devices. The portion of the material arrangement 100 as shown in the process flow 300 may be an example of a portion of a semiconductor device included on a single die. The one or more bumping operations may include forming layer 105-a-1. For example, solder bumps may be formed on UBM 115-e. Layer 105-a-1 may be formed using material 110-a, which may be an example of a solder material.

[0065] Such techniques for forming material arrangement 100 (e.g., using step 305-d-1, step 305-e-1, and step 305-f-1) may be associated with various challenges. For example, the PVD process used to form UBM 115-e may result in the formation of voids or cracks in or near sharp corners (e.g., thinned regions of UBM 115-e). Such thinned regions of UBM 115 may result in current pooling, or may be affected by a lack of effective cooling, which may result in failure. Some other reliability challenges may be associated with the presence of overhanging layer 105 edge regions of UBM 115. Such overhanging layers may result in mechanical stress (e.g., when layer 105-a-1 exerts a downward force on the overhanging region of UBM 115-e). Additionally, or alternatively, the bond or adhesion between the metallic material and the polymer material (eg, UBM 115 - e and layer 105 - f - 2 ) may be relatively weak when compared to adhesion between similar materials (eg, between two metals), which may result in delamination.

[0066] The present disclosure provides methods for effectively removing portions of UBM 115-a (e.g., removing portions 310-a and 310-b) that are associated with or otherwise cause various reliability challenges as described above. Such removal of portions 310-a and 310-b may be enabled or assisted by a variety of structural instabilities associated with UBM 115-a. For example, when removing material arrangement 100 from an adhesive film as described herein, the thinned region of UBM 115-a may be relatively weak and may be susceptible to cracking. Additionally, or alternatively, a relatively weak bond between UBM 115-a and layer 105-f-2 may result in delamination that enables removal of portions 310-a and 310-b.

[0067] In some cases, one or more processing steps that would otherwise increase adhesion between layer 105-f-2 and portion 310 may not be performed, which may improve processing speed and reduce processing costs. For example, one or more processing steps to remove carbon residue from the surface of layer 105-f-2 prior to forming UBM 115-a may be skipped, thereby reducing adhesion of UBM 115-a to layer 105-f-2 and enabling more efficient removal of portion 310 on the surface of layer 105-f-3. In addition, the techniques described herein enable the size of layer 105-a-2 (e.g., the diameter of the solder bump) to be reduced, which may reduce consumption of material 110-a and may improve space utilization.

[0068] According to one or more examples described herein, the following step 305 may be performed. At step 305-d-2, portion 310-a and portion 310-b (e.g., portion 310 of UBM 115-a) may be lifted off using layer 105-i. Layer 105-i may be formed using material 110-i (e.g., adhesive material, tape material). In some cases, layer 105-i may be an example of an adhesive film. As described herein, removal of portion 310 may be accomplished without the use of chemical products, which may reduce the costs and environmental impacts associated with such chemical products. Removal of portion 310 may result in side-on-side contact between UBM 115-b and layer 105-f-2. That is, the extent of UBM 115b relative to the x-direction may be aligned and in contact with the extent (e.g., inner extent) of layer 105-f-2 relative to the x-direction. Additionally, removing portion 310 from UBM 115-a may enable skipping of one or more operations performed at step 305-d-1. For example, formation of layer 105-h-3 and associated etching operations of UBM 115-e may not be performed, which may improve processing speed.

[0069] At step 305-e-2, one or more etching operations (e.g., spin etching operations) and one or more deposition operations (e.g., one or more PVD operations) may be performed. In some cases, the one or more deposition operations may include forming layer 105-j (e.g., on a rough surface of layer 105-f-2, on a grinded surface of layer 105-f-2). Layer 105-j may be formed using material 110-j. In some cases, material 110-j may be a composite or compound including one or more materials 110. For example, although shown as a single layer 105, layer 105-j may include one or more layers formed using one or more materials. In an illustrative example, layer 105-j may include a titanium layer, a nickel layer, and a silver layer. A titanium layer may be formed on the surface of layer 105-f-2, a nickel layer may be formed on the surface of the titanium layer, and a silver layer may be formed on the surface of the nickel layer.

[0070] At step 305-f-2, one or more dicing operations and one or more bumping operations may be performed. The one or more dicing operations may include slicing or cutting the material arrangement 100 into a plurality of semiconductor devices. The portion of the material arrangement 100 as shown in the process flow 300 may be an example of a portion of a semiconductor device included on a single die. The one or more bumping operations may include forming layer 105-a-2. For example, solder bumps may be formed on UBM 115-b. Layer 105-a-2 may be formed using material 110-a, which may be an example of a solder material. In some cases, layer 105-a-2 may have a smaller diameter or smaller size than layer 105-a-1, which may reduce manufacturing costs and improve space utilization of material arrangement 100.

[0071] Figure 4A and 4B A material arrangement 400 is shown that supports an improved under bump metallization structure and associated formation methods. The material arrangement 400 may be as described in reference Figure 1 The material arrangements 400 are examples of material arrangements 100 described above. In addition, the material arrangements 400 may each include one or more layers 105, which may be as described in reference Figure 1-3 The one or more layers 105 are described as examples. The one or more layers 105 may be formed using one or more materials 110, which may be reference Figure 1-3 Examples of material 110 are described. Material arrangement 400-b may be an example of a pillar configuration, and material arrangement 400-a may be an example of a bump configuration. As described herein, the techniques used to form material arrangement 400, and more specifically the techniques used to form UBM 115, may be applied to both bump and pillar configurations.

[0072] The material arrangements 400 may each include a layer 105-j, a layer 105-f, a layer 105-e, and a UBM 115. Figure 3 10 and UBM 115 are formed by one or more operations described in process flow 300 of the present invention. However, in some cases, as shown in material arrangement 400-a, layer 105-a (e.g., solder bump) can be formed on UBM 115. Layer 105-a can conform to the width of UBM 115 (e.g., along the x-direction). That is, the surface of layer 105-a that contacts UBM 115 can have the same width as UBM 115. In some cases, layer 105-a can be formed to avoid contact with layer 105f.

[0073] However, material arrangement 400-b may include one or more layers 105 between layer 105-b and UBM 115. For example, layer 105-L may be formed to contact UBM 115. Layer 105-L may have a cylindrical shape (e.g., with a height axis extending in the y-direction). Layer 105-L may be formed using material 110-k, which may be an example of a conductive material such as copper. In some cases, the diameter of layer 105-L may be less than the width of UBM 115. Layer 105-k may be formed to contact layer 105-L. Layer 105-k may also have a cylindrical shape with its height axis extending in the y-direction. Layer 105-k and layer 105-L may have the same diameter. Layer 105-k may be formed using material 110-j. Material 110-j may be an example of a conductive material such as nickel. Layer 105-b may be formed to contact layer 105-k.

[0074] As described herein, layer 105-a and layer 105-b may be coupled to UBM 115 and layer 105-e. During a reflow operation, layer 105-a and layer 105-b may melt or partially melt, during which material arrangement 400 may be coupled to one or more other devices. Thus, layer 105-a, layer 105-b, layer 105-k, layer 105-L, and UBM 115 may provide an electrical path for coupling one or more devices or electrical components to layer 105-e. As shown, UBM 115 may be formed on a surface of layer 105-e and may not be formed on a horizontal surface of layer 105-f, which may improve durability and reduce manufacturing costs associated with material arrangement 400.

[0075] Figure 5A and 5B A material arrangement 500 is shown that supports an improved under bump metallization structure and associated formation method. The material arrangement 500 may be as described in reference Figure 1 , Figure 4A and Figure 4B The material arrangements 100 and 400 are examples described. The material arrangements 500 may each include one or more layers 105, which may be as described in reference Figures 1 to 4B One or more layers 105 may be formed using one or more materials 110, which may be reference Figures 1 to 4B An example of material 110 is depicted. Material arrangement 500-a may be an example of a side view of a portion of material arrangement 400-a (eg, excluding solder bumps). Material arrangement 500-b may be an example of a top view of material arrangement 500-a.

[0076] Material arrangement 500 may illustrate layer 105 of UBM 115 after portion 310 of UBM 115 has been removed. In some cases, the material removal operation (e.g., to remove portion 310) may cause UBM 115 to break or be cut at different locations. In one illustrative example, Figure 5A and 5B As shown, when the material arrangement 500 is viewed from above, the cracking of the UBM 115 may cause the layers 105-g, 105-c, and 105-d to be visible. In this case, the portion of the layer 105 formed along (e.g., parallel to) the sidewall of the layer 105-f may not be removed. Therefore, when the material arrangement 500 is viewed from above, the vertical portions (e.g., extending along the y-direction) of the layers 105-c, 105-d, and 105-g may be visible. As shown, the UBM 115 (e.g., the layer 105-g, the layer 105-c, and the layer 105-d) may be formed on the surface of the layer 105-e and the sidewall of the layer 105-f. The UBM 115 may not be formed on the horizontal surface of the layer 105-f, which may improve durability and reduce the manufacturing costs associated with the material arrangement 500.

[0077] Figure 6 An example of a flow chart showing a method 600 that supports improved under bump metallization structures and associated formation methods is illustrated. The operations of method 600 may be implemented by a manufacturing system or one or more machines configured to perform one or more operations as described herein. In some cases, a manufacturing system or machine may execute instructions to control one or more functional elements to perform the described operations. Additionally or alternatively, a machine or manufacturing system may use dedicated hardware to perform various aspects of the described operations.

[0078] At 605, method 600 may include forming a first layer comprising a first material. In some cases, a top surface of the first layer may extend along a first direction and a second direction. The first direction may be parallel to a width of the first layer, and the second direction may be parallel to a depth of the first layer. The operations may be performed according to examples as described herein. In some examples, a dedicated machine or manufacturing system may be used to perform aspects of the operations.

[0079] At 610, method 600 may include forming a second layer on a top surface of at least the first layer. The second layer may include a second material. The operations may be performed according to examples as described herein. In some examples, a dedicated machine or manufacturing system may be used to perform various aspects of the operations.

[0080] At 615, method 600 may include forming a void in the second layer. In some cases, forming the void may expose a portion of the top surface of the first layer. The operations may be performed according to examples as described herein. In some examples, a dedicated machine or manufacturing system may be used to perform various aspects of the operations.

[0081] At 620, method 600 may include forming one or more layers on the top surface of the second layer and on the exposed portion of the top surface of the first layer. The operations may be performed according to examples as described herein. In some examples, a dedicated machine or manufacturing system may be used to perform aspects of the operations.

[0082] At 625, method 600 may include performing a material removal operation (e.g., a lift-off operation using an adhesive film). The material removal operation may remove one or more portions of the one or more layers formed on the top surface of the second layer. The operation may be performed according to examples as described herein. In some examples, a dedicated machine or manufacturing system may be used to perform aspects of the operation.

[0083] Figure 7 An example of a flow chart showing a method 700 that supports improved under bump metallization structures and associated formation methods is illustrated. The operations of method 700 may be implemented by a manufacturing system or one or more machines configured to perform one or more operations as described herein. In some cases, a manufacturing system or machine may execute instructions to control one or more functional elements to perform the described operations. Additionally or alternatively, a machine or manufacturing system may use dedicated hardware to perform various aspects of the described operations.

[0084] At 705, method 700 may include forming a first layer comprising a first material. In some cases, a top surface of the first layer may extend along a first direction and a second direction. The first direction may be parallel to a width of the first layer, and the second direction may be parallel to a depth of the first layer. The operations may be performed according to examples as described herein. In some examples, a dedicated machine or manufacturing system may be used to perform aspects of the operations.

[0085] At 710, method 700 may include forming a second layer on a top surface of at least the first layer. The second layer may include a second material. The operations may be performed according to examples as described herein. In some examples, a dedicated machine or manufacturing system may be used to perform various aspects of the operations.

[0086] At 715, method 700 may include forming a void in the second layer. In some cases, forming the void may expose a portion of the top surface of the first layer. The operations may be performed according to examples as described herein. In some examples, a dedicated machine or manufacturing system may be used to perform various aspects of the operations.

[0087] At 720, method 700 may include forming one or more layers on the top surface of the second layer. For example, method 700 may include forming a third layer including a third material on the top surface of the second layer and on an exposed portion of the top surface of the first layer. The operations may be performed according to examples as described herein. In some examples, aspects of the operations may be performed using a dedicated machine or manufacturing system.

[0088] At 725, method 700 may include forming a fourth layer including a fourth material on a top surface of the third layer. The operations may be performed according to examples as described herein. In some examples, aspects of the operations may be performed using a dedicated machine or manufacturing system.

[0089] At 730, method 700 may include forming a fifth layer including a fifth material on a top surface of the fourth layer. The operations may be performed according to examples as described herein. In some examples, aspects of the operations may be performed using a dedicated machine or manufacturing system.

[0090] At 735, method 700 may include performing a material removal operation (e.g., a lift-off operation using an adhesive film). The material removal operation may remove one or more portions of the one or more layers formed on the top surface of the second layer. The operation may be performed according to examples as described herein. In some examples, a dedicated machine or manufacturing system may be used to perform aspects of the operation.

[0091] Although this detailed description sets forth some embodiments of the invention, the appended claims also cover other embodiments of the invention that may differ from the described embodiments according to various modifications and improvements. In the appended claims, unless the specific terms "means for" or "step for" are used in a given claim, it is not intended that the claim be interpreted under 35 U.S.C. 112, paragraph 6.

Claims

1. A method comprising: forming a first layer comprising a first material, wherein a top surface of the first layer extends along a first direction and a second direction, the first direction being parallel to a width of the first layer and the second direction being parallel to a depth of the first layer; forming a second layer comprising a second material on at least a top surface of the first layer; forming a void in the second layer, wherein forming the void exposes a portion of a top surface of the first layer; forming one or more layers on a top surface of the second layer and on an exposed portion of the top surface of the first layer; and A material removal operation is performed, wherein the material removal operation lifts portions of the one or more layers formed on a top surface of the second layer away from the top surface.

2. The method of claim 1 , wherein forming the one or more layers comprises: forming a third layer including a third material on a top surface of the second layer and on an exposed portion of the top surface of the first layer; forming a fourth layer comprising a fourth material on a top surface of the third layer; and A fifth layer including a fifth material is formed on a top surface of the fourth layer. 3 . The method of claim 2 , wherein the first material comprises aluminum, the second material comprises silicon nitride, the third material comprises titanium, the fourth material comprises nickel, and the fifth material comprises silver. The method according to claim 2 , wherein a height dimension of the fourth layer is greater than or equal to 300 nanometers.

5. The method of claim 1 , wherein performing a material removal operation comprises: The portion of the one or more layers is removed using an adhesive film.

6. The method according to claim 1, further comprising: A sixth material is formed on a top layer of the one or more layers, wherein forming the sixth material avoids forming the sixth material in contact with the second layer. The method of claim 6 , wherein the sixth material comprises a solder material.

8. The method according to claim 1, further comprising: A sixth layer including the second material is formed, wherein the first layer is formed on the sixth layer.

9. The method according to claim 1, further comprising: A reflow operation is performed, wherein performing the reflow operation couples the first layer to the device via at least the one or more layers.

10. The method according to claim 1, further comprising: forming a pillar comprising a seventh material on a top layer of the one or more layers, wherein a height axis of the pillar extends along a third direction parallel to a height of the first layer; and A seventh layer including a fourth material is formed on the top surface of the pillar. The method of claim 1 , wherein the one or more layers include under bump metallization.

12. An apparatus comprising: a first layer comprising a first material, wherein the first layer has a width parallel to the first direction, a depth parallel to the second direction, and a height parallel to the third direction; a second layer including a second material formed on at least a top surface of the first layer, the top surface of the first layer extending along a first direction and a second direction; a void formed in the second layer, wherein the extent of the void includes a sidewall of the second layer and a portion of a top surface of the first layer, wherein the sidewall of the second layer is parallel to a third direction; and One or more layers are formed on the sidewalls of the second layer and on the portion of the top surface of the first layer, the one or more layers being used to couple the first layer with a bonding material.

13. The apparatus of claim 12, wherein the one or more layers comprise: a third layer comprising a third material, the third layer being formed on a top surface of the second layer; a fourth layer comprising a fourth material, the fourth layer being formed on a top surface of the third layer; and A fifth layer including a fifth material is formed on a top surface of the fourth layer.

14. The apparatus of claim 13, wherein the first material comprises aluminum, the second material comprises silicon nitride, the third material comprises titanium, the fourth material comprises nickel, and the fifth material comprises silver.

15. The device of claim 13, wherein a height dimension of the fourth layer is greater than or equal to 300 nanometers.

16. The apparatus of claim 12, wherein the bonding material comprises solder.

17. The apparatus according to claim 12, further comprising: A sixth layer includes the second material, wherein the first layer is formed on the sixth layer.

18. The apparatus according to claim 12, further comprising: a column comprising a seventh material, wherein a height axis of the column extends along a third direction; and A seventh layer including a fourth material is formed on the top surface of the pillar.

19. The apparatus of claim 12, wherein the one or more layers include under bump metallization.

20. A product formed by a process comprising the steps of: forming a first layer comprising a first material, wherein a top surface of the first layer extends along a first direction and a second direction, the first direction being parallel to a width of the first layer and the second direction being parallel to a depth of the first layer; forming a second layer comprising a second material on at least a top surface of the first layer; forming a void in the second layer, wherein forming the void exposes a portion of a top surface of the first layer; forming one or more layers on a top surface of the second layer and on an exposed portion of the top surface of the first layer; and A material removal operation is performed, wherein the material removal operation lifts portions of the one or more layers formed on a top surface of the second layer away from the top surface.

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