METHOD FOR PRODUCE A SEMICONDUCTOR DEVICE WITH A METAL SILICIDE LAYER

Abstract

A method for producing a semiconductor device, comprising: forming a first layer (112) over a silicon carbide (SiC) layer (102), wherein: the first layer (112) has a first surface (114) distal to the SiC layer (102) and a second surface (116) proximal to the SiC layer (102), and the first layer (112) comprises a metal; directing a first thermal energy (119) to the first surface (114) of the first layer (112) to form a metal silicide layer (120) from the metal of the first layer (112) and silicon of the SiC layer (102), wherein the metal silicide layer (120) has a first surface (122) distal to the SiC layer (102) and a second surface (124) proximal to the SiC layer (102); and directing a second thermal energy (121) onto the first surface (122) of the metal silicide layer (120), which is adjusted to reduce the surface roughness of the first surface (122) of the metal silicide layer (120).

Description

TECHNICAL AREA The present disclosure relates to semiconductor devices. BACKGROUND A semiconductor device can be used in mobile phones, laptops, desktops, tablets, watches, gaming systems, industrial electronics, commercial electronics, and / or consumer electronics. A semiconductor device may have an electronic contact between a semiconductor and a metal, which can be used to connect a component within the semiconductor device to an external circuit. Examples of semiconductor devices and fabrication methods are known from US 2014 / 0206190A1, US 2019 / 0157397A1, US 2019 / 0096998A1, and JP 2017-34027A. SUMMARY This summary is provided to introduce, in simplified form, a selection of concepts that are further described in detail below. This summary is not intended to identify key factors or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter. This invention is defined in independent claim 1. Further embodiments are defined in the dependent claims. To achieve the aforementioned and related objectives, the following description and accompanying drawings present certain illustrative aspects and realizations or implementations. These indicate only some of the various ways in which one or more aspects can be applied. Other aspects, advantages, and novel features of the disclosure will become apparent from the following detailed description when considered in conjunction with the accompanying drawings. DESCRIPTION OF THE DRAWINGS Fig. 1A schematically illustrates actions or processes for manufacturing a semiconductor device according to various examples. Fig. 1B schematically illustrates a process for manufacturing a semiconductor device according to various examples. Fig. 1C schematically illustrates a process for manufacturing a semiconductor device according to various examples. Fig. 1D schematically illustrates a process for manufacturing a semiconductor device according to various examples. Fig. 1E schematically illustrates a process for manufacturing a semiconductor device according to various examples. Fig. 2 is an illustration of an exemplary method according to the techniques presented herein. Fig. 3A schematically illustrates the execution of laser beams on the upper surface of a layer according to various examples.Figure 3B schematically illustrates the execution of laser shots on the top surface of a layer according to various examples. Figure 3C schematically illustrates the execution of laser shots on the top surface of a layer according to various examples. Figure 4A schematically illustrates the execution of laser shots on the top surface of a layer according to various examples. Figure 4B schematically illustrates the execution of laser shots on the top surface of a layer according to various examples. Figure 5 is an illustration of an exemplary method according to the techniques presented herein. Figure 6 schematically illustrates processes for fabricating a semiconductor device according to various examples. DETAILED DESCRIPTION The claimed subject matter is now described with reference to the drawings, using the same reference numerals throughout to refer to the same elements. For explanatory purposes, numerous specific details are set forth in the following description to provide a comprehensive understanding of the claimed subject matter. However, it should be obvious that the claimed subject matter can be implemented in practice without these specific details. In other cases, known structures and devices are represented in the form of block diagrams to facilitate a description of the claimed subject matter. It is understood that the following description of embodiments is not to be understood in a limiting sense. The scope of this disclosure is not to be limited by the embodiments described below or by the drawings, which are used only for illustration. The drawings are to be regarded as schematic representations, and elements illustrated in the drawings are not necessarily shown to scale. Rather, the various elements are depicted in such a way that their function and general purpose are apparent to a person skilled in the art. All numerical values ​​within the detailed description and claims herein are modified by “about” or “approximately” the stated value and take into account experimental errors and variations that a person skilled in the art would expect. The terms "over" and / or "overlapping" should not be understood as meaning only "directly above" and / or "in direct contact with". Rather, if an element lies "over" another element and / or overlaps it (e.g., one area overlaps another area), another element (e.g., another area) may be positioned between the two elements (e.g., another area may be positioned between a first area and a second area if the first area lies "over" the second area and / or overlaps it). Furthermore, if a first element lies "over" a second element and / or overlaps it, at least some part of the first element may coincide vertically with the second element, such that a vertical line can intersect the first and second elements. The semiconductor substrate or body may extend along a principal extent plane. The term "horizontal," as used in this description, is intended to describe an orientation substantially parallel to the principal extent plane. A first or predominantly horizontal side of the semiconductor substrate or body may be substantially parallel to horizontal directions or may have surface sections that form an angle of not more than 8° (or not more than 6°) with the principal extent plane. The first or predominantly horizontal side may, for example, be the surface of a wafer or a die / chip. Sometimes the horizontal direction is also referred to as the lateral direction. The term "vertical" as used in this description is intended to describe an orientation that is essentially perpendicular to the horizontal direction (e.g., parallel to the normal direction of the first side of the semiconductor substrate or body, or parallel to the normal direction of a surface section of the first side of the semiconductor substrate or body). A semiconductor device can have an electrical contact (e.g., a resistive contact) between a semiconductor and a metal. This electrical contact can be formed using a metal silicide layer between the semiconductor and the metal. The surface of the metal silicide layer may have a primary surface roughness and / or protrusions (e.g., local elevations of the metal silicide layer such as bumps or irregularities, hillocks, and / or small protrusions). The surface roughness and / or protrusions of a surface (e.g., a back surface) of the metal depend on the surface roughness and / or protrusions of the surface of the metal silicide layer. For example, a metal silicide layer with a higher surface roughness and / or larger protrusions can result in a surface of the metal that has a higher surface roughness and / or larger protrusions.In some examples, the metal surface can be electrically connected to a component such as at least one wafer testing fixture, a conductor frame, etc. Increased surface roughness and / or larger surface protrusions can reduce the conductivity of the electrical connection between the metal and the component, for example, due to enlarged voids between the metal and the component. According to the present disclosure, a semiconductor device and a method for fabricating the semiconductor device are provided. The semiconductor device may include a metal silicide layer. In some examples, the surface of the metal silicide layer may have a lower surface roughness, smaller and / or shorter protrusions of the metal silicide layer, and / or a reduced quantity or number of protrusions. In some examples, the metal silicide layer may be formed from a semiconductor layer (e.g., a silicon carbide (SiC) layer) and a first layer containing a metal superimposed on the semiconductor layer. In one example, initial thermal energy may be directed onto a surface of the first layer to form the metal silicide layer from the metal of the first layer and silicon of the semiconductor layer.A second thermal energy source can be directed onto a surface of the metal silicide layer to reduce the surface roughness of the upper surface of the metal silicide layer. This second thermal energy source can reduce the number, size, and / or height of protrusions on the surface of the metal silicide layer. One or more metal layers can be formed over the metal silicide layer (e.g., the metal silicide layer can provide electrical contact between the one or more metal layers and the semiconductor layer). The reduced surface roughness and / or the reduced number, size, and / or height of the surface protrusions can improve electrical contact (e.g.,ohmic contact) between the one or more metal layers and the semiconductor layer and / or a higher conductivity between the one or more metal layers and a component connected to the one or more metal layers, thereby creating improved operation and / or improved performance of the semiconductor device. In one embodiment of the presently disclosed embodiments, a method for fabricating a semiconductor device is provided. The method may include forming a first layer over a semiconductor layer, such as a semiconductor substrate. In some examples, the semiconductor layer is a SiC layer, such as a SiC substrate. In some examples, the first layer has a first surface distal to the SiC layer and a second surface proximal to the SiC layer. The first layer comprises a metal. In some examples, the metal comprises nickel, titanium, tantalum, tungsten, molybdenum, nickel aluminide (NiAl), titanium nitride (TiN), tantalum nitride (TaN), molybdenum nitride (MoN), tungsten nitride (WN), and / or another metal. The process may involve directing an initial thermal energy onto the first surface of the first layer to form a metal silicide layer from the metal of the first layer and silicon of the semiconductor layer. The initial thermal energy directed onto the first surface of the first layer melts the metal of the first layer and / or causes a silicide formation or silicidal reaction to occur between the metal and silicon of the semiconductor layer. In some examples, a measuring device may be used to perform one or more measurements indicating whether the metal of the first layer has been sufficiently melted by the initial thermal energy.In some examples, based on a determination that the metal of the first layer has not been sufficiently melted by the thermal energy, further thermal energy can be directed onto the first surface of the first layer. In some examples, the first thermal energy includes energy introduced into the first layer and / or the semiconductor layer by means of a laser that illuminates at least a region of the first surface of the first layer. For example, the laser may consist of a single laser pulse emitted from a laser source. In some examples, the first thermal energy may include energy introduced into the first layer and / or the semiconductor layer by means of multiple laser pulses (e.g., multiple laser pulses may be emitted from the laser source to illuminate different sections of the first surface of the first layer).Alternatively and / or additionally, the laser can include a continuous laser output or power from the laser source. The metal silicide layer has a first surface distal to the SiC layer and a second surface proximal to the SiC layer. The process may involve directing a second thermal energy onto the first surface of the metal silicide layer. The second thermal energy directed onto the first surface of the metal silicide layer melts (e.g., remelts) metal of the metal silicide layer. In some examples, the second thermal energy includes energy introduced into the metal silicide layer and / or the semiconductor layer by means of a laser that illuminates at least a region of the first surface of the metal silicide layer. For example, the laser may consist of a laser pulse emitted from a laser source. In some examples, the first thermal energy may consist of energy introduced into the metal silicide layer and / or the semiconductor layer by means of multiple laser pulses (e.g.,The laser source can emit multiple laser pulses to illuminate different sections of the first surface of the metal silicide layer. Alternatively and / or additionally, the laser can have a continuous laser output from the laser source. In some examples, before the second thermal energy is directed onto the first surface of the metal silicide layer, the first surface of the metal silicide layer exhibits a first surface roughness. After the second thermal energy is directed onto the first surface of the metal silicide layer, the first surface of the metal silicide layer exhibits a second surface roughness. The second surface roughness is lower than the first surface roughness (e.g., directing the second thermal energy onto the first surface of the metal silicide layer reduces the surface roughness of the first surface). For example, directing the second thermal energy onto the first surface of the metal silicide layer smooths the first surface of the metal silicide layer. Alternatively and / or additionally, before the second thermal energy is directed onto the first surface of the metal silicide layer, the first surface of the metal silicide layer may exhibit a first number of protrusions (e.g., local elevations of the metal silicide layer such as unevenness, bumps, and / or small hillocks). In some examples, after the second thermal energy is directed onto the first surface of the metal silicide layer, the first surface of the metal silicide layer exhibits a second number of protrusions. The second number of protrusions may be fewer than the first number (e.g., directing the second thermal energy onto the first surface of the metal silicide layer reduces the number of protrusions on the first surface).Alternatively and / or additionally, protrusions of the first surface of the metal silicide layer may be larger and / or higher before the second thermal energy is directed onto the first surface of the metal silicide layer compared to protrusions of the first surface after the second thermal energy is directed onto the first surface of the metal silicide layer (e.g., directing the second thermal energy onto the first surface of the metal silicide layer reduces the size and / or height of protrusions of the first surface). In some examples, the time interval between the first thermal energy being directed onto the first surface of the first layer and the second thermal energy being directed onto the first surface of the metal silicide layer is at least a threshold time. In one example, the first thermal energy melts the metal of the first layer to form molten metal, with the threshold time being based on a solidification time of the molten metal. The solidification time is the time the molten metal takes to solidify. In some examples, the solidification time depends on one or more properties of the metal, an energy level of the first thermal energy, and / or the time required for the energy of the first thermal energy introduced into the molten metal to dissipate.In one example, the threshold time is equal to or greater than the solidification time, so that the molten metal solidifies before the second time at which the second thermal energy is directed onto the first surface of the metal silicide layer. The threshold time can be in the range of at least 3 milliseconds to at most 1000 milliseconds and / or in the range of at least 3 milliseconds to at most 333 milliseconds. In some examples, the first layer contains silicon. The silicon can suppress carbon release during the formation of the metal silicide layer. For example, carbon from the semiconductor layer (e.g., the SiC layer) can diffuse into the metal silicide layer during its formation. In one example, carbon clusters can form within the metal silicide layer and / or a carbon layer can form on the first surface of the metal silicide layer. The inclusion or incorporation of silicon in the first layer can reduce the amount of carbon present in the metal silicide layer. The method may involve the formation of one or more metal layers over the metal silicide layer after the second thermal energy has been directed onto the first surface of the metal silicide layer. The method may involve the deposition of a metal layer from the one or more metal layers onto a conductor frame. In some examples, the metal layer is soldered to the conductor frame. The metal silicide layer may provide an electrical contact (e.g., a resistive contact) between the semiconductor layer and the one or more metal layers. In some examples, the first layer is formed to have a thickness of less than 200 nanometers. The thickness of the first layer can range from at least 10 nanometers to at most 200 nanometers, from at least 10 nanometers to at most 100 nanometers, and / or from at least 10 nanometers to at most 30 nanometers. In the first scenario, the thickness of the first layer can range from at least 10 nanometers to at most 30 nanometers. In the second scenario, the thickness of the first layer can be greater than or equal to 40 nanometers. The surface roughness of the first surface of the metal silicide layer formed in the first scenario can be lower than the surface roughness of the first surface of the metal silicide layer formed in the second scenario.Alternatively and / or additionally, projections of the first surface of the metal silicide layer formed in the first scenario can be smaller and / or shorter than projections of the first surface of the metal silicide layer formed in the second scenario. In one embodiment of the presently disclosed embodiments, a method for fabricating a semiconductor device is provided. The method may include forming a first layer over a semiconductor layer, such as a semiconductor substrate. In some examples, the semiconductor layer is a SiC layer, such as a SiC substrate. In some examples, a first-layer electrical contact region has a first surface distal to the semiconductor layer and a second surface proximal to the semiconductor layer. The first layer contains a metal. In some examples, the metal includes nickel, titanium, tantalum, tungsten, molybdenum, NiAl, TiN, TaN, MoN, WN, and / or another metal. In some examples, the first-layer electrical contact region corresponds to a first-layer region from which a metal silicide layer is formed to create an electrical contact (e.g., a resistive contact) between the semiconductor layer and one or more metals. In a first example, the region for forming an electrical contact encompasses the entire first layer. In this example, the first surface of the region for forming an electrical contact is a surface of the first layer. In a second example, the region for forming an electrical contact comprises a region of the first layer. In this example, the first surface of the region for forming an electrical contact is a region of a surface of the first layer. The method can involve performing a multitude of laser pulses on the first surface of the area to form an electrical contact of the first layer, thereby creating a metal-silicide layer from the metal of the first layer and silicon of the semiconductor layer. A laser pulse of the multitude of laser pulses (and / or each laser pulse of the multitude of laser pulses) comprises illuminating a section of the first surface with a laser pulse. Each section of the first surface is illuminated by at least two laser pulses of the multitude of laser pulses. In some examples, the multitude of laser shots comprises a first laser shot and a second laser shot. The first laser shot involves illuminating a first section of the first surface with a first laser pulse. The second laser shot involves illuminating the first section of the first surface with a second laser pulse. The time interval between the first and second laser shots is at least a threshold interval. In some examples, the first laser pulse melts the metal of the first layer to form molten metal, with the threshold time based on the solidification time of the molten metal (e.g., the time the molten metal needs to solidify). In some examples, the solidification time depends on one or more properties of the metal, an energy level of the first laser pulse, and / or the time required for the energy of the first laser pulse introduced into the molten metal to dissipate. In one example, the threshold time is equal to or greater than the solidification time, so the molten metal solidifies before the second laser pulse. The threshold time can range from at least 3 milliseconds to at most 1000 milliseconds and / or from at least 3 milliseconds to at most 333 milliseconds. In some examples, after the first laser shot and before the second laser shot, the first section of the first surface exhibits a first surface roughness. After the second laser shot, the first section of the first surface exhibits a second surface roughness. The second surface roughness is less than the first surface roughness (e.g., performing the second laser shot reduces the surface roughness of the first section of the first surface). For example, performing the second laser shot smooths the first section of the first surface. Alternatively and / or additionally, after the first laser shot and before the second laser shot, the first section of the first surface may exhibit an initial number of protrusions. In some examples, after the second laser shot, the first section of the first surface exhibits a second number of protrusions. The second number of protrusions may be fewer than the first number (e.g., performing the second laser shot reduces the number of protrusions on the first section of the first surface). Alternatively and / or additionally, protrusions on the first section of the first surface of the metal silicide layer before the second laser shot may be larger and / or higher compared to protrusions on the first section of the first surface after the second laser shot (e.g., performing the second laser shot reduces the size and / or height of the protrusions on the first section of the first surface). In some examples, the first laser pulse illuminates a second section of the first surface, which contains the same section as the first surface. The second laser pulse illuminates a third section of the first surface, which contains the same section as the first surface. The third section of the first surface is offset from the second section of the first surface. The third section and the second section overlap in the first section. In some examples, the first layer is designed to have a thickness of less than 200 nanometers. The thickness of the first layer can range from at least 10 nanometers to at most 200 nanometers, from at least 10 nanometers to at most 100 nanometers, and / or from at least 10 nanometers to at most 30 nanometers. In some examples, the first layer contains silicon. The silicon can suppress carbon release during the formation of the metal silicide layer. The process can involve forming one or more metal layers over the metal silicide layer after the numerous laser shots have been performed. The process can involve depositing a metal layer consisting of one or more metal layers onto a conductor frame. The metal layer can be soldered to the conductor frame. In one embodiment of the presently disclosed embodiments, a semiconductor device is provided. The semiconductor device may comprise a semiconductor layer, such as a semiconductor substrate. In some examples, the semiconductor layer is a SiC layer, such as a SiC substrate. The semiconductor layer may comprise a metal silicide layer over the semiconductor layer. The metal silicide layer has a first surface distal to the semiconductor layer and a second surface proximal to the semiconductor layer. The surface roughness of the first surface is at most 200 nanometers. The semiconductor device may comprise one or more metal layers over the metal silicide layer. The surface roughness of the metal layers may correspond to an average surface roughness of the first surface (e.g., a surface roughness averaged over the first surface).For example, the average vertical extent of projections and / or valleys of the first surface can be at most 200 nanometers (e.g., the average vertical extent can be an average of the vertical extents of the projections and / or valleys of the first surface). In some examples, the thickness of the metal silicide layer is less than 300 nanometers. In some examples, the metal includes nickel, titanium, tantalum, tungsten, molybdenum, NiAl, TiN, TaN, MoN, WN and / or another metal. In some examples, a metal layer consisting of one or more metal layers is attached to a conductor frame. The metal layer may be soldered to the conductor frame. Figures 1A-1E illustrate aspects relating to the fabrication of a semiconductor device according to various examples of the present disclosure. In 1001 (illustrated in Figure 1A), a semiconductor layer 102 is provided. The semiconductor layer 102 can comprise a crystalline semiconductor material. The semiconductor layer 102 can comprise a semiconductor element (e.g., silicon, germanium, and / or another semiconductor element) and / or a semiconductor compound (e.g., SiC, silicon germanium (SiGe), gallium arsenide (GaAs), gallium nitride (GaN), and / or another semiconductor compound). The semiconductor layer 102 can comprise dopants (e.g., nitrogen (N), phosphorus (P), beryllium (Be), boron (B), aluminum (Al), gallium (Ga), and / or other dopants). Alternatively and / or additionally, the semiconductor layer 102 can comprise impurities or defects (e.g., hydrogen, fluorine, oxygen, and / or other defects).In some examples, the semiconductor layer 102 is a semiconductor substrate such as a SiC substrate. The thickness 108 of the semiconductor layer 102 can be in the range of at least 10 micrometers to at most 500 micrometers, in the range of at least 50 micrometers to at most 200 micrometers, and / or in the range of at least 80 micrometers to at most 140 micrometers. The semiconductor layer 102 has a first surface 104 and a second surface 106 opposite the first surface 104. In some examples, the first surface 104 corresponds to a back side of the semiconductor layer 102 (e.g., a back side of a wafer). In some examples, the second surface 106 corresponds to a front side of the semiconductor layer 102 (e.g., a front side of a wafer). In 1002 (illustrated in Fig. 1A), a first layer 112 is formed over the semiconductor layer 102. The first layer 112 comprises a metal. In some examples, the metal includes nickel, titanium, tantalum, tungsten, molybdenum, NiAl, TiN, TaN, MoN, WN, and / or another metal. The first layer 112 can overlay the semiconductor layer 102. In some examples, the first layer 112 can include a non-metal (for example, in addition to the metal), such as silicon, to suppress carbon release during the formation of the metal silicide from the first layer 112 and the semiconductor layer 102.In one example, the first layer 112 comprises nickel and silicon, with the nickel present in the range of at least 2 wt% to at most 95 wt%, at least 2 wt% to at most 50 wt%, at least 6 wt% to at most 16 wt%, and / or at least 10 wt% to at most 12 wt%. The first layer 112 has a first surface 114 distal to the semiconductor layer 102 and a second surface 116 proximal to the semiconductor layer 102. In some examples, the second surface 116 of the first layer 112 may be adjacent to and / or in contact (e.g., direct contact) with the first surface 104 of the semiconductor layer 102. In some examples, the first layer 112 is formed via a sputtering process, which includes sputtering the first layer 112 onto the first surface 104 of the semiconductor layer 102.In some examples, the first layer 112 has a thickness 118 of less than 200 nanometers. The thickness 118 of the first layer 112 can be in the range of at least 10 nanometers to at most 200 nanometers, in the range of at least 10 nanometers to at most 100 nanometers, and / or in the range of at least 10 nanometers to at most 30 nanometers. At 1003 (for which examples are illustrated in Fig. 1B-1C), a first thermal energy 119 is directed onto the first surface 114 of the first layer 112 to form a metal silicide layer 120 from the metal of the first layer 112 and the silicon of the semiconductor layer 102. The metal silicide layer 120 has a first surface 122 distal to the semiconductor layer 102 and a second surface 124 proximal to the semiconductor layer 102. In some examples, the metal silicide layer 120 forms an electrical contact, such as an ohmic contact, between the semiconductor layer 102 and one or more metal layers (e.g., one or more metal layers 606, shown in Fig. 6).For example, the metal silicide layer 120 can provide a connection between an external circuit arrangement and one or more components arranged within the semiconductor device, such as one or more components embedded in the semiconductor layer 102. In some examples, the one or more components arranged within the semiconductor device include a transistor, such as an insulated-gate bipolar transistor (IGBT), a field-effect transistor (FET), a metal-oxide-semiconductor FET (MOSFET), and / or another type of transistor. In one example, the electrical contact may be connected to and / or correspond to a drain of the transistor, such as a drain of a MOSFET.In some examples, the one or more components arranged in the semiconductor device include a diode, wherein the electrical contact may be connected to and / or correspond to an electrode of the diode. Fig. 1B illustrates an example 1003a of the process 1003 in which the first thermal energy 119 is directed onto the entire first surface 114 of the first layer 112. Fig. 1C illustrates an example 1003b of the process 1003, in which the first thermal energy 119 is directed onto a region 126 of the first surface 114 of the first layer 112. In some examples, the region 126 of the first surface 114 corresponds to an upper surface of a region 127 for forming an electrical contact of the first layer 112. In some examples, the region 127 for forming an electrical contact of the first layer 112 corresponds to a region of the first layer 112 from which the metal silicide layer 120 is formed to form an electrical contact. In some examples, as shown in Fig. 1C, the region 127 for forming an electrical contact may be only a region of the first layer 112. In some examples, as shown in Fig. 1B, the region 127 for forming an electrical contact may comprise the entire first layer 112. In some examples, the first thermal energy 119 is directed onto the first surface 114 of the first layer 112 to heat at least a region of the first layer 112 and / or at least a region of the semiconductor layer 102 to a first temperature, where the first temperature can be in the range of at least 900° Celsius to at most 1300° Celsius, in the range of at least 950° Celsius to at most 1100° Celsius, and / or in the range of at least 970° Celsius to at most 1010° Celsius. The first thermal energy 119, directed onto the first surface 114 of the first layer 112, melts metal of the first layer 112 and / or causes a silicidal reaction to take place. In an example where the first layer 112 has nickel and the semiconductor layer 102 has SiC, the silicidal reaction can involve Si + 2Ni → Ni2Si + C.Alternatively and / or additionally, in an example where the first layer has 112 nickel and the semiconductor layer has 102 SiC, the metal silicide layer 120 has at least one of Ni2Si, Ni31Si12, Ni3Si etc. In some examples, the process 1003 is carried out such that one or more regions of the semiconductor device are not heated to the first temperature. In one example, the first thermal energy 119 can be directed onto the first surface 114 of the first layer 112 such that the silicidal reaction occurs without damaging one or more components located in the one or more regions of the semiconductor device (e.g., the first thermal energy 119 can be localized onto a first region of the semiconductor device to induce the silicidal reaction, the first region being able to include at least some part of the first layer 112 and / or some part of the semiconductor device). In some examples, the one or more regions of the semiconductor device can include a region of the semiconductor layer 102 proximal to the second surface 106 of the semiconductor layer 102 (e.g.,(the one or more components are arranged in the region of the semiconductor layer 102). In one example, process 1003 comprises performing one or more laser shots on the first surface 114 of the first layer 112, such as one or more laser shots of a laser thermal annealing (LTA) process (e.g., the one or more laser shots may comprise a first plurality of laser shots shown in and / or described with reference to Figs. 3A-3C). At 1004 (for which examples are illustrated in Fig. 1D - 1E), a second thermal energy 121 is directed onto the first surface 122 of the metal silicide layer 120 to reduce the surface roughness of the first surface 122 of the metal silicide layer 120. In some examples, the thickness 128 (shown in Fig. 1D) of the metal silicide layer 120 is less than 300 nanometers (e.g., the thickness 128 can be greater than the thickness 118 of the first layer 112). Fig. 1D illustrates an example 1004a of operation 1004, in which operation 1004 is performed after example 1003a of operation 1003 (shown in Fig. 1B) has been performed. Fig. 1E illustrates an example 1004b of operation 1004, in which operation 1004 is performed after example 1003b of operation 1003 (shown in Fig. 1C) has been performed. In some examples, the second thermal energy 121 is directed onto the first surface 122 of the metal silicide layer 120 to heat at least a region of the metal silicide layer 120 to a second temperature, where the second temperature can be in the range of at least 900° Celsius to at most 1300° Celsius, in the range of at least 950° Celsius to at most 1100° Celsius, and / or in the range of at least 970° Celsius to at most 1010° Celsius. In some examples, the second temperature is approximately the same as the first temperature. In some examples, the second thermal energy 121, directed onto the first surface 122 of the metal silicide layer 120, melts the metal of the metal silicide layer 120. In some examples, process 1004 is performed such that one or more regions of the semiconductor device are not heated to the second temperature. For example, the second thermal energy 121 can be directed onto the first surface 122 of the metal silicide layer 120 such that a second region of the semiconductor device (e.g., the second region can comprise the metal silicide layer 120 and / or at least a certain portion of the semiconductor device) is heated without damaging one or more components located in the one or more regions of the semiconductor device (e.g., the second thermal energy 121 can be localized to the second region of the semiconductor device). In one example, process 1004 involves performing one or more laser shots on the first surface 122 of the metal silicide layer 120, such as one or more laser shots of an LTA process (e.g.,The one or more laser shots can comprise the second plurality of laser shots shown in Fig. 3A - 3C and / or described in relation to them). In some examples, the time interval between a first time point at which the first thermal energy 119 is directed onto the first surface 114 of the first layer 112, and a second time point at which the second thermal energy 121 is directed onto the first surface 122 of the metal silicide layer 120, is at least a threshold time interval. In some examples, the threshold time interval is based on (is, for example, greater than or equal to) the solidification time of a molten metal (e.g., the metal melted by the first thermal energy 119). In some examples, after performing operation 1003 and before performing operation 1004, the first surface 122 of the metal silicide layer 120 exhibits a first surface roughness. In other examples, after performing operation 1004, the first surface 122 of the metal silicide layer 120 exhibits a second surface roughness. The second surface roughness is less than the first surface roughness (e.g., performing operation 1004 reduces the surface roughness of the first surface 122). For example, performing operation 1004 smooths the first surface 122 of the metal silicide layer 120. Alternatively and / or additionally, after performing operation 1003 and before performing operation 1004, the first surface 122 of the metal silicide layer 120 may have a first number of protrusions. In some examples, after operation 1004 has been performed, the first surface 122 of the metal silicide layer 120 has a second number of protrusions. The second number of protrusions may be fewer than the first number of protrusions (e.g., performing operation 1004 reduces the number of protrusions on the first surface 122). Alternatively and / or additionally, the protrusions of the first surface 122 of the metal silicide layer 120 may be larger and / or higher before performing the process 1004 compared to protrusions of the first surface 122 after performing the process 1004 (e.g., performing the process 1004 reduces the size and / or height of the protrusions of the first surface 122). Fig. 2 illustrates an exemplary method 200 for fabricating a semiconductor device. In 202, a first layer (e.g., the first layer 112) is formed over a semiconductor layer (e.g., the semiconductor layer 102, such as a SiC layer). The first layer has a first surface (e.g., the first surface 114) distal to the semiconductor layer and a second surface (e.g., the second surface 116) proximal to the semiconductor layer. The first layer comprises a metal. In 204, a first thermal energy (e.g., the first thermal energy 119) is directed onto the first surface of the first layer to form a metal silicide layer (e.g., the metal silicide layer 120) from the metal of the first layer and silicon of the semiconductor layer. The metal silicide layer has a first surface (e.g., the first surface 122) distal to the semiconductor layer and a second surface (e.g., the second surface 116) proximal to the semiconductor layer.the second surface 124) proximal to the semiconductor layer. At 206, a second thermal energy (e.g., the second thermal energy 121) is directed onto the first surface of the metal silicide layer to reduce the surface roughness of the first surface of the metal silicide layer. Figures 3A-3C and 4A-4B illustrate aspects relating to the execution of a plurality of laser shots on an upper surface 306 of a first layer (e.g., the first layer 112) to form a metal silicide layer (e.g., the metal silicide layer 120) from a metal of the first layer and silicon of a semiconductor layer (e.g., the semiconductor layer 102) located below the first layer. In one example, the upper surface 306 of the first layer corresponds to the first surface 114 of the first layer 112, shown in Figure 1B. In another example, the upper surface 306 of the first layer corresponds to the region 126 of the first surface 114 of the first layer 112, shown in Figure 1C (e.g., the upper surface 306 corresponds to an upper surface of the contact formation region 127 of the first layer 112).A laser shot of the plurality of laser shots comprises illuminating a section of the upper surface 306 with a laser pulse. Each section of the upper surface 306 is illuminated by means of at least two laser shots of the plurality of laser shots. Figures 3A-3C illustrate a first example of performing the multiple laser shots. Exemplary boundaries of the upper surface 306 of the first layer are shown with a box in a dotted line. The multiple laser shots can include a first multiple laser shots (described, for example, with respect to operations 3001-3003 of Figures 3A-3B) and a second multiple laser shots (described, for example, with respect to operations 3004-3005 of Figures 3B-3C). In some examples, the first multiple laser shots are performed in a first LTA process, which is carried out to illuminate (e.g., irradiate) the upper surface 306 (e.g., the entire upper surface 306) at least once. For example, a metal of the first layer can be melted over the upper surface 306 of the first layer at least once during the first LTA process. In 3001 (shown in Fig. 3A), a first laser shot of the first plurality of laser shots illuminates (e.g., irradiates) an illumination area or surface LS1, which comprises a region of the upper surface 306, with a laser pulse. For example, the first laser shot can be performed using a laser source. The first laser shot causes metal of the first layer within the illumination area LS1 to melt, forming molten metal. In some examples, the width 302 of the illumination area LS1 is between at least 10 millimeters and at most 20 millimeters, for example, approximately 15 millimeters. In some examples, the length 304 of the illumination area LS1 is between at least 10 millimeters and at most 20 millimeters, for example, approximately 15 millimeters. In some examples, the width 302 is approximately equal to the length 304.In some examples, the size of the illumination area LS1 depends on the laser source, such as the power capacity of laser shots through the laser source. For example, the size can be a function of the power capacity, with the size increasing as the power capacity increases. In device 3002 (shown in Fig. 3A), a second laser pulse illuminates an illumination area LS2, which includes a region of the upper surface 306. In some examples, the illumination area LS2 overlaps with the illumination area LS1 in an overlap region OR1. In some examples, the second laser pulse is delivered such that the illumination area LS2 overlaps with the illumination area LS1 to ensure that every section of the upper surface 306 is illuminated by a laser pulse (e.g., so that no area between the illumination area LS1 and the illumination area LS2 remains unheated or uncured during the first set of laser pulses). Accordingly, a section of the upper surface 306 with the overlap region OR1 is illuminated by two laser pulses (e.g., the first laser pulse and the second laser pulse). In some examples, a wafer with its first layer is placed on a wafer table that controls the wafer's position. For instance, between the first laser shot (e.g., process 3001) and the second laser shot (e.g., process 3002), the position of the wafer and / or the wafer table is changed from a first position (e.g., the position of the wafer and / or the wafer table when the first laser shot is performed) to a second position (e.g., the position of the wafer and / or the wafer table when the second laser shot is performed) such that the illumination area LS2 (illuminated by the laser pulse emitted from the laser source) is offset relative to the illumination area LS1, and / or such that the illumination area LS2 overlaps with the illumination area LS1 in the overlap region OR1. In some examples, the position of the wafer and / or the wafer table is adjusted using a motor (e.g.,a stepper motor), which controls a position of the wafer table, changed from the first position to the second position. At 3003 (shown in Fig. 3B), laser shots of the first plurality of laser shots (e.g., remaining laser shots of the first plurality of laser shots after the first and second laser shots) are performed to illuminate other illumination areas (e.g., other than illumination areas LS1 and LS2) that have regions of the upper surface 306 with laser pulses. In one example, the other illumination areas include an illumination area LS3, which is illuminated by a third laser shot of the first plurality of laser shots, an illumination area LS4, which is illuminated by a fourth laser shot of the first plurality of laser shots, and so on. Laser shots of the first plurality of laser shots can be performed sequentially until the illumination areas of the first plurality of laser shots cover an area that includes the entire upper surface 306. As shown in Fig.As shown in Figure 3B, the illumination areas of the first plurality of laser shots can cover the entire upper surface 306. In some examples, at least a portion of one or more illumination areas of the first plurality of laser shots (e.g., illumination area LS1, illumination area LS2, illumination area LS4, etc.) lies outside the upper surface 306 to ensure that the entire upper surface 306 is illuminated by at least one laser shot of the first plurality of laser shots. In one example, the illumination area LS2 overlaps with the illumination area LS3 in an overlap region OR2 (e.g., a section of the upper surface within the overlap region OR2 is illuminated by two laser shots, such as the second and third laser shots). The illumination area LS3 can overlap with the illumination area LS4 in an overlap region OR3 (e.g., a section of the upper surface 306 within the overlap region OR3 is illuminated by two laser shots, such as the third and fourth laser shots). The illumination area LS4 can overlap with the illumination area LS1 in an overlap region OR4 (e.g., a section of the upper surface 306 within the overlap region OR4 is illuminated by two laser shots, such as the fourth and first laser shots).In an overlap region OR5, the illumination area LS1, the illumination area LS2, the illumination area LS3 and the illumination area LS4 can overlap (e.g., a section of the upper surface 306 within the overlap region OR5 is illuminated by four laser shots). In some examples, the protrusions of the first surface within overlapping regions (e.g., overlapping regions OR1, OR2, OR3, OR4, OR5, etc.) of the illumination surfaces of the first plurality of laser shots may be larger in number, size and / or height compared with sections of the upper surface 306 that are illuminated by only a single laser shot of the first plurality of laser shots. In some examples, the second set of laser shots is performed in a second LTA process, which is carried out to illuminate (e.g., irradiate) the top surface 306 (e.g., the entire top surface 306) at least once. For example, metal of the first layer can be melted at least once via the top surface 306 of the first layer during the second LTA process. In 3004 (shown in Fig. 3B), a fifth laser shot of the second plurality of laser shots illuminates (e.g., irradiates) an illumination area LS5, which has a region of the upper surface 306, with a laser pulse. The fifth laser shot melts metal of the first layer within the illumination area LS5 to form molten metal. For clarity, in Fig. 3B, the illumination area LS5 is shown with a solid box overlaid with illumination areas of the first plurality of laser shots, which are shown with dashed boxes. In some examples, as shown in Fig. 3B, the illumination area LS5 is offset 322 relative to the illumination area LS1. In one example, the offset 322 between the illumination area LS5 and the illumination area LS1 is realized as follows:This is implemented such that a corner 323 of the illumination surface LS5 lies at a point within the illumination surface LS1, such as approximately at a center point of the illumination surface LS1. In some examples, illumination surfaces of the second plurality of laser shots can be offset relative to illumination surfaces of the first plurality of laser shots 322 (e.g., each illumination surface of the second plurality of laser shots can be offset relative to an illumination surface of the first plurality of laser shots 322 such that a corner of the illumination surface of the second plurality of laser shots lies at a point such as approximately at a center point of the illumination surface of the first plurality of laser shots). In one example, the illumination area LS5 overlaps with the illumination area LS1 in an overlap region OR6 (e.g., a section of the upper surface 306 is illuminated with the overlap region OR6 by two laser shots from the plurality of laser shots). In an overlap region OR7, the illumination areas LS5, LS1, and LS2 can overlap (e.g., a section of the upper surface 306 within the overlap region OR7 is illuminated by three laser shots from the plurality of laser shots). The illumination area LS5 can overlap with the illumination area LS2 in an overlap region OR8 (e.g., a section of the upper surface 306 within the overlap region OR8 is illuminated by two laser shots from the plurality of laser shots). In an overlap region OR9, the illumination areas LS5, LS2, and LS3 can overlap (e.g.,A section of the upper surface 306 within the overlap region OR9 is illuminated by three laser shots from the plurality of laser shots. The illumination area LS5 can overlap with the illumination area LS3 in an overlap region OR10 (e.g., a section of the upper surface 306 within the overlap region OR10 is illuminated by two laser shots from the plurality of laser shots). In an overlap region OR11, the illumination areas LS5, LS3, and LS4 can overlap (e.g., a section of the upper surface 306 within the overlap region OR11 is illuminated by three laser shots from the plurality of laser shots). The illumination area LS5 can overlap with the illumination area LS4 in an overlap region OR12 (e.g., a section of the upper surface 306 within the overlap region OR12 is illuminated by two laser shots from the plurality of laser shots).In an overlap region OR13, the illumination areas LS5, LS4, and LS1 can overlap (e.g., a section of the upper surface 306 within the overlap region OR13 is illuminated by three laser shots from the plurality of laser shots). In an overlap region OR14, the illumination areas LS5, LS4, LS3, LS2, and LS1 can overlap (e.g., a section of the upper surface 306 within the overlap region OR14 is illuminated by five laser shots from the plurality of laser shots). At 3005 (shown in Fig. 3C), laser shots of the second plurality of laser shots (e.g., remaining laser shots of the second plurality of laser shots after the fifth laser shot) are performed to illuminate other illumination areas (e.g., other than the illumination area LS5) that have regions of the upper surface 306 with laser pulses. For clarity, in Fig. 3C, illumination areas of the second plurality of laser shots are shown with solid lines and illumination areas of the first plurality of laser shots are shown with dashed lines. In some examples, an area comprising illumination areas of the second plurality of laser shots is offset 322 from an area comprising illumination areas of the first plurality of laser shots (e.g., a pattern of the second plurality of laser shots is offset 322 from a pattern of the first plurality of laser shots).Laser shots of the second plurality of laser shots can be performed sequentially until the illumination areas of the second plurality of laser shots cover an area encompassing the entire upper surface 306. As shown in Fig. 3C, illumination areas of the second plurality of laser shots can cover the entire upper surface 306. In some examples, at least a portion of some illumination areas of the second plurality of laser shots lies outside the upper surface 306, thus ensuring that the entire upper surface 306 is illuminated by at least one laser shot of the second plurality of laser shots. In some examples, the realization or implementation of the offset 322 between the illumination areas of the first plurality of laser shots and the illumination areas of the second plurality of laser shots ensures that laser shots are applied more uniformly to sections of the upper surface. By implementing the offset 322, the plurality of laser shots can, for example, be configured such that at least one of one or more sections of the upper surface 306 is illuminated by two laser shots of the plurality of laser shots (e.g., the one or more sections of the upper surface 306 illuminated by two laser shots can lie within at least one of the overlap regions OR6, OR8, OR10, OR12, etc.), or one or more sections of the upper surface 306 are illuminated by three laser shots of the plurality of laser shots (e.g.,The one or more sections of the upper surface 306 illuminated by three laser shots can lie within at least one of the overlap regions OR7, OR9, OR11, OR13, etc., and / or one or more sections of the upper surface 306 can be illuminated by five laser shots of the plurality of laser shots (e.g., the one or more sections of the upper surface 306 illuminated by five laser shots can lie within an overlap region OR14 and / or other overlap regions). Accordingly, by adjusting the offset 322, the difference between a maximum number of laser shots (e.g., five) applied to a single section of the upper surface 306 and a minimum number of laser shots (e.g., two) applied to a single section of the upper surface 306 can be three.In a scenario where the offset 322 is not implemented, such as a scenario where illumination areas of the second plurality of laser shots coincide with illumination areas of the first plurality of laser shots, one or more sections of the upper surface 306 can be illuminated by two laser shots of the plurality of laser shots, one or more sections of the upper surface 306 can be illuminated by four laser shots of the plurality of laser shots, and / or one or more sections of the upper surface 306 can be illuminated by eight laser shots of the plurality of laser shots. Accordingly, without implementing the offset 322, a difference can exist between a maximum number of laser shots (e.g., eight) applied to a single section of the upper surface 306 and a minimum number of laser shots (e.g.,two), which are applied to a single section of the upper surface 306, amount to six. The smaller difference achieved by implementing the offset 322 can provide for lower surface roughness and / or smaller and / or shorter protrusions of the metal silicide layer formed by performing the plurality of laser shots. It is apparent that embodiments can be considered in which illumination areas of the second plurality of laser shots coincide with illumination areas of the first plurality of laser shots (such as when each illumination area of ​​the second plurality of laser shots is approximately the same as an illumination area of ​​the first plurality of laser shots). In some examples, laser shots of the multitude can be performed based on the threshold time. For example, a first laser shot with a first illumination area that overlaps with a second illumination area of ​​a second laser shot preceding the first laser shot can be performed when or after the threshold time has elapsed since a time at which the second laser shot was performed. In one example, the fifth laser shot associated with illumination area LS5 can be performed at a first time, where the first time can be based on times at which one or more laser shots are performed that are associated with illumination areas overlapping with illumination area LS5.For example, the one or more laser shots can include the first laser shot assigned to the first illumination area LS1, the second laser shot assigned to illumination area LS2, the third laser shot assigned to illumination area LS3, and the fourth laser shot assigned to illumination area LS4. The time interval between the first shot and the times at which the one or more laser shots are performed can be equal to or greater than the threshold time. Accordingly, in an example where the threshold time is equal to or greater than the solidification time, the metal of the first layer within illumination area LS5 is melted by the one or more laser shots, with the molten metal solidifying before the fifth laser shot is performed on illumination area LS5. Figures 4A-4B illustrate a second example of performing the multiple laser shots. Exemplary boundaries of the upper surface 306 of the first layer are shown with a box in a dotted line. In 4001 (shown in Figure 4A), a first laser shot of the multiple laser shots illuminates (e.g., irradiates) an illumination area LS1, which has a region of the upper surface 306, with a laser pulse. In 4002 (shown in Figure 4A), a second laser shot of the multiple laser shots illuminates an illumination area LS2, which has a region of the upper surface 306, with a laser pulse. In comparison with the first example of performing the multiple laser shots, which is shown in Figures 3A-3C, the second laser shot in the second example (which is shown and / or described in Figures 4A-4B) can correspond to a laser shot of the second multiple laser shot in the first example (e.g.,The illumination area LS2 of the second laser shot can coincide with the illumination area LS5 of the fifth laser shot of the second plurality of laser shots, whereas in the second example, the second laser shot can be performed before the completion of the first plurality of laser shots. In some examples, the illumination area LS2 is offset relative to the illumination area LS1. In one example, the offset 322 between the illumination area LS2 and the illumination area LS1 is implemented such that a corner 402 of the illumination area LS2 lies at a point within the illumination area LS1, such as approximately at a midpoint of the illumination area LS1. The illumination area LS2 can overlap with the illumination area LS1 in an overlap region OR1. In some examples, the time interval between the first laser shot and the second laser shot is equal to or greater than the threshold time interval. In 4003 (shown in Fig. 4B), a third laser shot of the plurality of laser shots illuminates (e.g., irradiates) an illumination area LS3, which comprises a region of the upper surface 306, with a laser pulse. The illumination area LS3 can overlap with the illumination area LS1 and / or the illumination area LS2 in overlap regions OR2, OR3, and / or OR4. In some examples, the time interval between the second laser shot and the third laser shot is equal to or greater than the threshold time interval. In 4004 (shown in Fig. 4B), a fourth laser shot of the plurality of laser shots illuminates (e.g., irradiates) an illumination area LS4, which has a region of the upper surface 306, with a laser pulse. In some examples, the time interval between the third and fourth laser shots is equal to or greater than the threshold time interval. In some examples, the illumination area LS4 is offset 322 relative to the illumination area LS3. In one example, the offset 322 between the illumination area LS4 and the illumination area LS3 is implemented such that a corner 404 of the illumination area LS4 lies at a point within the illumination area LS3, such as approximately at a midpoint of the illumination area LS3. The illumination area LS4 can overlap with the illumination area LS2 and / or the illumination area LS3 in overlap regions OR5, OR6, and / or OR7.In some examples, the time interval between the third laser shot and the fourth laser shot is equal to or greater than the threshold time interval. In some examples, after the fourth laser shot is performed, remaining laser shots of the plurality of laser shots are performed (e.g., laser shots of the plurality of laser shots are performed until illumination areas of the plurality of laser shots cover an area encompassing the entire surface 306, and / or each section of the upper surface 306 is illuminated by at least two laser shots of the plurality of laser shots). In one example, illumination areas of the plurality of laser shots can have the arrangement of illumination areas shown in Fig. 3C. In some examples, the sequence in which laser shots of the multitude of laser shots are performed may differ from the exemplary sequences shown and / or described in Fig. 3A - 3C and / or Fig. 4A - 4B. In some examples, by performing the multitude of laser shots according to one or more of the techniques provided herein (e.g., illustrated in Figs. 3A-4B and / or Figs. 4A-4B and / or described with respect to them), an upper surface of the metal silicide layer (e.g., the metal silicide layer 120) formed from metal of the first layer and silicon of the semiconductor layer can have an upper surface (e.g., the first surface 122) that has a lower surface roughness (and / or a reduced number of protrusions and / or smaller and / or shorter protrusions) compared with a metal silicide layer formed without the use of one or more of the techniques provided herein.For example, the lower surface roughness (and / or the reduced number of protrusions and / or the smaller and / or shorter protrusions) may be a result of performing the multitude of laser shots such that each section of the upper surface 306 is illuminated by at least two laser shots (instead of sections of the upper surface 306 being illuminated by only one laser shot, for example). Fig. 5 illustrates an exemplary method 500 for fabricating a semiconductor device. In 502, a first layer (e.g., the first layer 112) is formed over a semiconductor layer (e.g., the semiconductor layer 102, such as a SiC layer). An area for forming an electrical contact of the first layer has a first surface (e.g., the upper surface 306) distal to the semiconductor layer and a second surface proximal to the semiconductor layer. In some examples, the area for forming an electrical contact comprises the entire first layer (e.g., the first surface 114 corresponds to the first surface 114 of the first layer 112). In other examples, the area for forming an electrical contact comprises a region of the first layer (e.g., the first surface corresponds to region 126 of the first surface 114 of the first layer 112, shown in Fig. 1C). The first layer comprises a metal.In 504, a plurality of laser shots (e.g., the plurality of laser shots shown and / or described in Figs. 3A-3C and / or 4A-4B) is performed on the first surface of the region to form an electrical contact of the first layer in order to form a metal silicide layer (e.g., the metal silicide layer 120) from the metal of the first layer and silicon of the semiconductor layer. One laser shot of the plurality of laser shots comprises illuminating a section of the first surface with a laser pulse. Each section of the first surface is illuminated by two laser shots of the plurality of laser shots. Fig. 6 illustrates aspects relating to the fabrication of a semiconductor device according to various examples of the present disclosure. In 6001, a semiconductor structure comprising the semiconductor layer 102 and a metal silicide layer 602 is provided. The metal silicide layer 602 can be formed using one or more of the techniques provided herein, such as those shown and / or described in Figs. 1A-1E, Fig. 2, Figs. 3A-3C, Figs. 4A-4B, and / or Fig. 5. For example, the metal silicide layer 602 can be formed to have a surface 604 with reduced surface roughness compared with a second metal silicide layer formed without using one or more of the techniques herein.In one example, the second metal silicide layer can be formed using an LTA process that illuminates at least some sections of the layer's surface with a single laser pulse. The surface of the second metal silicide layer may exhibit protrusions with local elevations of up to approximately 400 nanometers and / or even up to approximately 1000 nanometers. However, the surface 604 of the metal silicide layer 602 formed using one or more of the techniques provided herein may have fewer protrusions than the surface of the second metal silicide layer, and / or the protrusions on the surface 604 of the metal silicide layer 602 may have a maximum local elevation of approximately 140 nanometers. In 6002, one or more metal layers 606 are formed over the metal silicide layer 602. For example, the one or more metal layers 606 can be formed in a backside metal (BSM) process. In some examples, the one or more metal layers 606 can be in contact (e.g., direct contact) with the surface 604 of the metal silicide layer 602. In one example, the metal silicide layer 602 forms an electrical contact (e.g., an ohmic contact) between the one or more metal layers 606 and the semiconductor layer 102. In some examples, a metal layer of the one or more metal layers 606 can be formed by a sputtering process, a vapor deposition or evaporation process, and / or one or more other deposition processes. In some examples, the reduced surface roughness of surface 604 of the metal silicide layer 602 leads to a reduced surface roughness of surface 608 of one or more metal layers 606. In one example, surface 608 of one or more metal layers 606 can correspond to an upper surface of a top metal layer of one or more metal layers 606. In some examples, surface 608 corresponds to a back surface of a wafer having the semiconductor layer 102, the metal silicide layer 602, and / or one or more metal layers 606.In some examples, as a result of the formation of the metal silicide layer 602 using one or more of the techniques provided herein, the surface 608 of the one or more metal layers 606 may exhibit reduced surface roughness and / or may exhibit a reduced number of protrusions and / or a reduced size and / or height of the protrusions. In some examples, one or more operations can be performed after operation 6001 and / or before operation 6002. In some examples, the one or more operations involve the removal of carbon from the metal silicide layer 602 (such as the removal of carbon from surface 604) using one or more liquids and / or gases. In one example, an oxygen plasma can be applied to surface 604 (for example, by performing an O2 flush) to remove the carbon. In some examples, the one or more operations involve the removal of oxide from the metal silicide layer 602 (such as the removal of an oxide from surface 604) using one or more liquids and / or one or more gases, such as the use of one or more corrosive chemicals (e.g., hydrofluoric acid and / or one or more other corrosive chemicals). In one example, the oxide can be a metal oxide (e.g.,nickel oxide in a scenario in which the metal silicide layer 602 is formed from a layer containing nickel) and / or silicon oxide (e.g. the oxide may be formed as a result of applying the oxygen plasma to the surface 604). In 6003, the wafer is attached to a conductor frame 610. In some examples, the top metal layer of one or more metal layers 606 is attached to the conductor frame 610 via the surface 608. For example, the surface 608 of the top metal layer of the one or more metal layers 606 can be soldered to the conductor frame 610, the top metal layer having a thickness greater than one, some, and / or all of the other metal layers of the one or more metal layers 606. In some examples, there can be fewer and / or smaller voids between the surface 608 of the metal layer and the conductor frame 610, such as because the surface 608 has a reduced surface roughness and / or because the surface 608 has a reduced number of protrusions and / or a reduced size and / or height of the protrusions.The smaller and / or fewer cavities can provide an improved electrical connection between the one or more metal layers 606 and the conductor frame 610, which can lead to improved operation and / or performance of a system encompassing the wafer. In some examples, the wafer may undergo a wafer inspection process (e.g., the wafer inspection process may be performed on the wafer prior to operation 6003). During the wafer inspection process, the surface 608 may be in contact (e.g., direct contact) with a measuring fixture configured to measure a current from the one or more metal layers 606. The surface 608 with reduced surface roughness and / or the surface 608 with a reduced number of protrusions and / or reduced protrusion size and / or height may result in improved contact between the measuring fixture and the surface 608 (i.e., increased conductivity between the one or more metal layers 606 and the measuring fixture), thus enabling more accurate measurements (e.g., current measurements) during the wafer inspection process. Alternatively and / or additionally, the wafer with the metal silicide layer 602 may exhibit an improved VF (transmittance voltage) distribution and / or improved VF values ​​compared with other wafers with metal silicide layers (e.g., the second metal silicide layer) formed without the use of one or more of the techniques provided herein. Some semiconductor devices formed without one or more of the techniques provided herein are formed with thicker metal layers in an effort to bury protrusions on the surface of a metal silicide layer. It can be seen that implementing one or more of the techniques provided herein allows the one or more metal layers 606 to be formed with reduced thicknesses, for example, because the surface 608 has a reduced surface roughness and / or because the surface 608 has a reduced number of protrusions and / or a reduced size and / or height of the protrusions. The reduced thicknesses of the one or more metal layers 606 can result in lower material costs and / or a smaller size of the semiconductor device. It can be seen that some techniques typically used to smooth semiconductor surfaces, such as chemical-mechanical polishing and / or planarizing (CMP), if performed on the metal silicide layer 602, can damage the layer and / or fail to smooth it. For example, performing CMP on the metal silicide layer 602 to smooth it can damage the layer and / or remove areas of it, resulting in the formation of an electrical contact (e.g., a resistive contact) that does not function correctly. According to some embodiments, a method for manufacturing a semiconductor device is provided. The method comprises forming a first layer over a SiC layer, wherein the first layer has a first surface distal to the SiC layer and a second surface proximal to the SiC layer, and wherein the first layer comprises a metal; directing a first thermal energy to the first surface of the first layer to form a metal silicide layer from the metal of the first layer and silicon of the SiC layer, wherein the metal silicide layer has a first surface distal to the SiC layer and a second surface proximal to the SiC layer; and directing a second thermal energy to the first surface of the metal silicide layer to reduce the surface roughness of the first surface of the metal silicide layer. According to some embodiments, a time interval between a first time point at which the first thermal energy is directed to the first surface of the first layer and a second time point at which the second thermal energy is directed to the first surface of the metal silicide layer is at least a threshold time interval. According to some embodiments, the first thermal energy directed on the first surface of the first layer melts metal of the first layer to form molten metal, the threshold time is based on a solidification time of the molten metal, and the molten metal solidifies before the second time point. According to some embodiments, the method, after directing the second thermal energy to the first surface of the metal silicide layer, includes forming one or more metal layers over the metal silicide layer. According to some embodiments, the method involves attaching one layer of one or more metal layers to a conductor frame. According to some embodiments, the metal contains nickel. According to some embodiments, the first layer is designed to have a thickness of less than 200 nanometers. According to some embodiments, a method for fabricating a semiconductor device is provided. The method comprises forming a first layer over a SiC layer, wherein a region for forming an electrical contact of the first layer has a first surface distal to the SiC layer and a second surface proximal to the SiC layer, and wherein the first layer comprises a metal, and performing a plurality of laser pulses on the first surface of the region for forming an electrical contact of the first layer to form a metal silicide layer from the metal of the first layer and silicon of the SiC layer, wherein a laser pulse of the plurality of laser pulses comprises illuminating a section of the first surface with a laser pulse, and wherein each section of the first surface is illuminated by at least two laser pulses of the plurality of laser pulses. According to some embodiments, the plurality of laser shots comprises a first laser shot and a second laser shot, the first laser shot comprises illuminating a first section of the first surface with a first laser pulse, the second laser shot comprises illuminating the first section of the first surface with a second laser pulse, and a time interval between the first laser shot and the second laser shot is at least a threshold time interval. According to some embodiments, the first laser shot melts metal of the first layer to form molten metal, the threshold time is based on a solidification time of the molten metal, and the molten metal solidifies before the second laser shot. According to some embodiments, after the first laser shot and before the second laser shot, the first section of the first surface has a first surface roughness, and after the second laser shot, the first section of the first surface has a second surface roughness that is less than the first surface roughness. According to some embodiments, a second section of the first surface, which includes the first section of the first surface, is illuminated with the first laser pulse, a third section of the first surface, which includes the first section of the first surface, is irradiated with the second laser pulse, the third section of the first surface is offset relative to the second section of the first surface, and the third section and the second section overlap in the first section. According to some embodiments, after performing the plurality of laser shots, the method includes forming one or more metal layers over the metal silicide layer and attaching one layer of the one or more metal layers to a conductor frame. According to some embodiments, the first layer contains silicon. According to some embodiments, the metal contains nickel. According to some embodiments, the first layer is designed to have a thickness of less than 200 nanometers. According to some embodiments, a semiconductor device is provided. The semiconductor device comprises a SiC layer, a metal silicide layer over the SiC layer, wherein the metal silicide layer has a first surface distal to the SiC layer and a second surface proximal to the SiC layer, and wherein the surface roughness of the first surface is at most 200 nanometers, and one or more metal layers over the metal silicide layer. According to some embodiments, the thickness of the metal silicide layer is less than 300 nanometers. According to some embodiments, the metal silicide layer contains nickel. According to some embodiments, one layer of one or more metal layers is attached to a conductor frame. It can be seen that combinations of one or more embodiments described herein, including combinations of embodiments described with reference to different figures, are considered herein. Although the subject matter has been described in a language specific to structural features and / or methodological processes, it should be understood that the subject matter defined in the attached claims is not necessarily limited to the specific features or processes described above. Rather, the specific features and processes described above are disclosed as exemplary ways of implementing the claims. Any aspect or design described herein as an “example” should not necessarily be considered advantageous over other aspects or designs. Rather, the use of the word “example” is intended to present a possible aspect and / or implementation that may be included in the techniques presented herein. Such examples are not necessary or intended to be limiting for such techniques. Different embodiments of such techniques may include such an example, alone or in combination with other features, and / or may vary and / or omit the illustrated example. As used in this application, the term "or" is intended to mean an inclusive "or" and not an exclusive "or". That is to say, unless otherwise stated or clear from the context, "X uses A or B" is intended to mean any of the natural inclusive permutations. That is to say, if X uses A, uses XB, or uses both A and B, then in each of the preceding cases, "X uses A or B" is satisfied. Furthermore, the indefinite article "a", as used in this application and the attached claims, is to be generally understood to mean "one or more", unless otherwise stated or it is clear from the context that it refers to a singular form. Unless otherwise stated, "first", "second", or the like are also not intended to imply any temporal aspect, spatial aspect, order, etc. Rather, such terms are used only as identifiers, names, etc.Used for features, elements, objects, etc. For example, a first element and a second element generally correspond to an element A and an element B, or to two different or two identical elements, or to the same element. Although the disclosure has been presented and described with respect to one or more implementations, equivalent changes and modifications will also occur to the person skilled in the art based on reading and understanding this description and the accompanying claims. The disclosure encompasses all such modifications and changes and is limited only by the scope of the following claims. In particular, with regard to the various functions performed by the components described above (e.g., elements, resources, etc.), the terms used to describe such components, unless otherwise specified, shall correspond to any component that performs the specified function of the described component (e.g.,(which is functionally equivalent), even if it is not structurally equivalent to the disclosed structure that performs the function in the exemplary implementations of the disclosure illustrated herein. Furthermore, while a particular feature of the disclosure may have been disclosed with respect to only one of several implementations, such a feature may be combined with one or more other features of the other implementations, as may be desirable and advantageous for any given or particular application. Moreover, to the extent that the terms "contains," "exhibiting," "has," "with," or variations thereof are used in either the detailed description or the claims, such terms shall be understood to be inclusive, similar to the terms "exhibiting" or "comprising."

Claims

A method for producing a semiconductor device, comprising: forming a first layer (112) over a silicon carbide (SiC) layer (102), wherein: the first layer (112) has a first surface (114) distal to the SiC layer (102) and a second surface (116) proximal to the SiC layer (102), and the first layer (112) comprises a metal; directing a first thermal energy (119) to the first surface (114) of the first layer (112) to form a metal silicide layer (120) from the metal of the first layer (112) and silicon of the SiC layer (102), wherein the metal silicide layer (120) has a first surface (122) distal to the SiC layer (102) and a second surface (124) proximal to the SiC layer (102); and directing a second thermal energy (121) onto the first surface (122) of the metal silicide layer (120), which is adjusted to reduce the surface roughness of the first surface (122) of the metal silicide layer (120). Method according to claim 1, wherein: a time period between a first time point at which the first thermal energy (119) is directed to the first surface (114) of the first layer (112) and a second time point at which the second thermal energy (121) is directed to the first surface (122) of the metal silicide layer (120) is at least a threshold time period. Method according to claim 2, wherein: the first thermal energy (119) directed onto the first surface (114) of the first layer (112) melts metal of the first layer (112) to form molten metal, the threshold time is based on a solidification time of the molten metal, and the molten metal solidifies before the second time point. Method according to one of the preceding claims, comprising: after directing the second thermal energy (121) onto the first surface (122) of the metal silicide layer (120), forming one or more metal layers over the metal silicide layer (120). Method according to claim 4, comprising: attaching a layer of one or more metal layers to a conductor frame. The method of claim 1, wherein: the metal comprises nickel. Method according to claim 1, wherein: the first layer is formed such that it has a thickness of less than 200 nanometers. A method according to one of the preceding claims, wherein directing a first thermal energy (119) onto the first surface (114) of the first layer (112) and directing a second thermal energy (121) onto the first surface (122) of the metal silicide layer (120) is carried out by performing a plurality of laser shots on the first surface (114), wherein: a laser shot of the plurality of laser shots comprises illuminating a section of the first surface (114) with a laser pulse and each section of the first surface (114) is illuminated by means of at least two laser shots of the plurality of laser shots. Method according to claim 8, wherein: the plurality of laser shots comprises a first laser shot and a second laser shot, the first laser shot comprises illuminating a first section of the first surface (114) with a first laser pulse, the second laser shot comprises illuminating the first section of the first surface (114) with a second laser pulse, and a time interval between the first laser shot and the second laser shot is at least a threshold time interval. Method according to claim 9, wherein: the first laser shot melts metal of the first layer (112) to form molten metal, the threshold time is based on a solidification time of the molten metal, and the molten metal solidifies before the second laser shot. Method according to one of the two preceding claims, wherein: after the first laser shot and before the second laser shot the first section of the first surface (114) has a first surface roughness and after the second laser shot the first section of the first surface (114) has a second surface roughness which is less than the first surface roughness. The method of claim 9, wherein: a second section of the first surface (114) comprising the first section of the first surface (114) is illuminated with the first laser pulse, a third section of the first surface (114) comprising the first section of the first surface (114) is illuminated with the second laser pulse, the third section of the first surface (114) is offset relative to the second section of the first surface (114), and the first section and the second section overlap in the first section. The method of claim 8, comprising: after performing the plurality of laser shots, forming one or more metal layers over the metal silicide layer (120); and attaching one layer of the one or more metal layers to a conductor frame. Method according to claim 8, wherein: the first layer (112) comprises silicon. Method according to claim 8, wherein: the metal comprises nickel. Method according to claim 8, wherein: the first layer (112) is formed such that it has a thickness of less than 200 nanometers.

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