JP2009529245A - Method and apparatus for heat treatment structure formed on a substrate - Google Patents

Abstract

The present invention generally describes one or more apparatus and various methods used to perform an annealing process on a desired area of a substrate. In one embodiment, a large amount of energy is delivered to the surface of the substrate to preferentially dissolve certain desired areas of the substrate to remove unwanted damage created from previous processing steps, The dopant is more evenly distributed in the various regions of the substrate and / or the various regions of the substrate are activated. The preferential dissolution process allows a more uniform distribution of the dopant in the dissolution region because of the increased diffusion rate and solubility of the dopant atoms in the dissolution region of the substrate. Thus, the creation of the dissolved region is: 1) redistributing the dopant atoms more uniformly, 2) removing the defects created in the pretreatment step, and 3) forming a region with a very abrupt dopant concentration. Make it possible.
[Selection] Figure 1

Description

Background of the Invention

Field of Invention
[0001] Embodiments of the present invention generally relate to a method of manufacturing a semiconductor device. More specifically, the present invention is directed to a substrate heat treatment method.

Explanation of related technology
[0002] The integrated circuit (IC) market is constantly demanding increased memory capacity, faster switching speeds and smaller feature sizes. One of the major steps the industry has taken to address these demands is a change from batch processing of silicon wafers in a large furnace to processing single wafers in a small chamber.

  [0003] During such single wafer processing, the wafer is typically heated to a high temperature, and various chemical and physical reactions can occur in multiple IC devices defined on the wafer. Interestingly, the favorable electrical performance of IC devices requires the annealing of the implant region. Annealing re-creates a more crystalline structure from regions of the wafer that are already amorphous, and activates the dopant by incorporating atoms into the crystal lattice of the substrate or wafer. Thermal processes such as annealing require a relatively large amount of thermal energy to be provided to the wafer in a short period of time, after which the wafer is rapidly cooled to terminate the thermal process. Examples of thermal processes currently in use include rapid thermal processing (RTP) and impulse (spike) annealing. Although such processes are widely used, current technology is not ideal. There is a tendency to ramp the wafer temperature fairly slowly and expose the wafer to high temperatures for a fairly long time. These problems become more severe with respect to increasing wafer size, increasing switching speed and / or reducing feature size.

  [0004] Generally, these thermal processes heat the substrate under controlled conditions according to a predetermined thermal recipe. These thermal recipes basically consist of the temperature at which the semiconductor substrate is to be heated at a temperature change rate, i.e., an increase and decrease rate, and the time during which the heat treatment system remains at a specific temperature. For example, a thermal recipe may need to heat a substrate from room temperature to a specific temperature of 1200 ° C. or higher in order to process multiple times at each specific temperature that extends up to 60 seconds or more.

  [0005] Furthermore, in order to meet certain objectives such as minimal internal diffusion of material between different regions of the semiconductor substrate, the time that each semiconductor substrate is exposed to high temperatures must be limited. To achieve this, both the rising and falling temperature ramp rates are preferably high. In other words, it is desirable to be able to adjust the temperature of the substrate from a low temperature to a high temperature or vice versa in the shortest possible time.

  [0006] The requirement of a high temperature ramp rate leads to the development of rapid thermal processing (RTP), where the normal temperature rise rate is 200-400 ° C / second compared to 5-15 ° C / min for conventional furnaces It extends to. The normal rate of decline is in the range of 80-150 ° C./second. The disadvantage of RTP is that the entire wafer is heated even if the IC device resides only in the top few microns of the silicon wafer. This will limit the rate at which the wafer can be heated and cooled. Furthermore, when the entire wafer becomes hot, the heat may be dissipated into the surrounding spaces and structures. As a result, today's modern RTP systems have struggled to achieve an increase rate of 400 ° C./sec and a decrease rate of 150 ° C./sec.

  [0007] Various scanning laser annealing techniques have been used to anneal the surface of a substrate in order to solve some of the problems that have arisen with conventional RTP type processes. In general, these techniques deliver a constant energy flux to a small area on the surface of the substrate, whereas the substrate is converted or scanned for energy delivered to the small area. Because of the strict uniformity requirements and the complexity of minimizing overlap of the scan area across the substrate surface, these types of processes are not effective for thermally treated contact level devices formed on the surface of the substrate.

  [0008] In view of the above, there is a need for a method of annealing a semiconductor substrate at a high rise and fall rate. This provides greater control over the fabrication of smaller devices that lead to increased performance.

Summary of the Invention

  [0009] The present invention generally modifies the one or more regions of a substrate formed from the first material by placing a second material in the one or more regions, the method comprising: Modifying one or more regions of the substrate with two materials is adapted to reduce the melting point of the first material contained in the one or more regions; Disposing a third material in one or more regions and delivering a large amount of electromagnetic energy to a surface of a substrate in thermal communication with the one or more regions, wherein the large amount of electromagnetic energy Adapted to melt the first material in the one or more regions, and a method of heat treating the substrate.

  [0010] Embodiments of the present invention further provide a substrate having one or more first regions that are modified so that the melting point of the material contained in each of the first regions is Melting at a lower temperature than the material contained in the second region of the substrate, wherein each of the second region and the first region is generally adjacent to the surface of the substrate. Depositing a coating on the surface of the substrate, the coating having a different absorption and reflection coefficient than the surface of the substrate, each of the first regions or the second region Removing a portion of the coating from the surface of the substrate that is generally adjacent to the substrate, and an area on the surface of the substrate containing the one or more first regions and the second region Send a large amount of electromagnetic energy A step, a method of multi amount of electromagnetic energy to heat treatment a substrate comprising the steps of preferentially dissolves the material in the first region of one or more said.

  [0011] Embodiments of the present invention further comprise providing a substrate formed from a substrate material and forming a buried region formed from a first material on a surface of the substrate, the first The material having a first thermal conductivity and depositing a second layer formed from the second material in the buried region, the second material having a second thermal conductivity. Forming a semiconductor device on the surface of the substrate, wherein a portion of the formed semiconductor device contains a portion of the second layer, and the second layer Delivering a large amount of electromagnetic energy to a surface of the substrate in thermal communication with the substrate, wherein the large amount of electromagnetic energy reaches a melting point of a portion of the second material in thermal communication with the embedded region. Steps that are adapted to To provide a method for heat treating a semiconductor substrate comprising.

  [0012] Embodiments of the present invention further comprise positioning a substrate on a substrate support, wherein the substrate is formed on a plurality of surfaces formed on a surface of the substrate containing a first region and a second region. Having a feature; depositing a coating on the first and second regions, wherein the material from which the coating is formed has a desired heat capacity; and on the first region Removing a portion of the coating such that the thickness of the coating has a desired thickness, wherein the average heat capacity across the substrate surface after removal of the portion of the coating is generally uniform; Delivering a large amount of electromagnetic energy to an area containing the first region and the second region, the large amount of electromagnetic energy dissolving the material in the first region. A method, a method of heat-treating the substrate with a.

  [0013] Embodiments of the present invention further comprise positioning a substrate forming a first feature and a second feature on a surface of the substrate, wherein the second feature is a first feature. And a second region, positioning the substrate on a substrate support, depositing a coating on the first and second features, and applying the coating to the second region Removing a portion of the coating so as to be disposed and exposing a surface of the first feature; and a large amount of electromagnetic in the area containing the first feature and the second feature Delivering energy, wherein the amount of electromagnetic energy dissolves the material in the first region of the second feature.

  [0014] Embodiments of the present invention further deliver a first amount of electromagnetic energy at one or more desired wavelengths to the back surface of the substrate 1 generally adjacent to the front surface of the substrate. Dissolving one or more regions of material, wherein the back surface and the front surface are on opposite sides of the substrate, and the front surface of the substrate is formed on the one or more regions A method of heat treating a substrate comprising the step of containing a semiconductor device is provided.

  [0015] Embodiments of the present invention further comprise delivering a first amount of electromagnetic energy to a first region on the surface of the substrate, wherein the first amount of electromagnetic energy is in the first region. Dissolving the substrate material in the substrate and making the crystalline substrate material amorphous, injecting a second material into the amorphous first region, and applying a second amount of electromagnetic energy to the first region. Delivering to a region, wherein the second amount of electromagnetic energy dissolves the material in the first region.

  [0016] Embodiments of the present invention further include an apparatus for heat treating a semiconductor substrate, the substrate support having a substrate support surface, and a heating element adapted to heat the substrate disposed on the substrate support. And an intense light source adapted to deliver a large amount of radiation to a region on the surface of the substrate disposed on the substrate support surface.

  [0017] Embodiments of the present invention are further an apparatus for heat treating a semiconductor substrate, adapted to deliver a first amount of energy to a region on the surface of the substrate disposed on a substrate support surface. A first intense light source that is disposed on the substrate support surface and a second intense light source adapted to deliver a second amount of electromagnetic energy to the region on the surface of the substrate. Monitoring the first amount of energy delivered to the region on the surface of the substrate, and the time between the first and second amounts of energy delivery, and the second amount And a controller adapted to control the amount of energy to achieve a desired temperature in the region.

  [0018] Embodiments of the present invention further include an apparatus for heat treating a semiconductor substrate, the substrate support having a substrate support surface and an aperture formed in the substrate support, and the aperture formed in the substrate support; And a first light source adapted to deliver a large amount of radiation to a first area of the substrate through a rear surface of the substrate opposite the front surface of the substrate, the substrate The front surface of the substrate includes one or more semiconductor devices formed thereon and is adapted to dissolve the region in which the large amount of radiation is contained in the first area. Equipment is provided.

  [0019] Embodiments of the present invention further include a method of heat treating a substrate, the step of positioning the substrate on a substrate support, and a first on a surface of the substrate in thermal communication with a first region of the substrate. Delivering a plurality of electromagnetic energy pulses to an area of the substrate, the step of delivering a plurality of electromagnetic energy pulses delivering a first pulse of electromagnetic energy to the surface of the substrate; and Delivering a second pulse of electromagnetic energy to the surface of the substrate and between the start of the first pulse and the start of the second pulse so that the material contained in the first region dissolves Adjusting the time of the method.

  [0020] Embodiments of the present invention further include a method of heat treating a substrate, the step of positioning the substrate on a substrate support, and the substrate in thermal communication with the first region and the second region of the substrate Delivering electromagnetic energy to the surface of the substrate, the step of delivering electromagnetic energy delivering a first amount of electromagnetic energy at a first wavelength and not the second region. Preferentially dissolving the material contained in the region, and delivering a second amount of electromagnetic energy at the second wavelength to be contained in the first region rather than the second region. Preferentially dissolving the material, wherein the step of delivering a second amount of electromagnetic energy and the step of delivering the first amount of electromagnetic energy overlap in time I will provide a.

  [0021] Embodiments of the present invention further comprise positioning the substrate on a substrate support and delivering electromagnetic energy to a surface of the substrate in thermal communication with the first region and the second region of the substrate. And the step of delivering electromagnetic energy comprises adjusting the shape of one pulse of electromagnetic energy as a function of time to preferentially dissolve the material contained in the first region. I will provide a.

  [0022] In order that the above-cited features of the present invention may be understood in detail, a more specific description of the invention briefly summarized above may be had by reference to an embodiment thereof. The parts are illustrated in the accompanying drawings. However, the attached drawings illustrate only typical embodiments of the invention, and the invention is tolerant of other equally effective embodiments and should therefore be considered as limiting this scope. Note that this is not the case.

Detailed description

  [0037] The present invention generally improves the performance of the implantation annealing step used in the process of manufacturing semiconductor devices on a substrate. In general, this method of the present invention may be used to preferentially anneal a selected region of a substrate by delivering sufficient energy to the selected region to remelt and solidify them.

  [0038] In general, the term "substrate" as used herein can be formed from any material that has an inherent conductivity capability, or a material that can be modified to provide a conductivity capability. Typical substrate materials include, but are not limited to, semiconductors such as silicon (Si) and germanium (Ge), and other compounds that exhibit semiconductor properties. Such semiconductor compounds generally include III-V and II-VI group compounds. Exemplary group III-V semiconductor compounds include, but are not limited to, gallium arsenide (GaAs), gallium phosphide (GaP), and gallium nitride (GaN). In general, the term semiconductor substrate includes a bulk semiconductor substrate as well as a substrate on which a deposited layer is disposed. To this end, the deposited layer of some semiconductor substrates processed by the method of the present invention is formed by either homoepitaxial (eg, silicon on silicon) or heteroepitaxial (eg, GaAs on silicon) growth. For example, the method of the present invention may be used in combination with a gallium arsenide substrate and a gallium nitride substrate formed by a heteroepitaxial method. Similarly, the method of the present invention can also be used to form integrated devices such as thin film transistors (TFTs) on a relatively thin crystalline silicon layer that is formed on an insulating substrate (eg, a silicon on insulator [SOI] substrate). It is applicable to.

  [0039] In one embodiment of the present invention, a large amount of energy is delivered to the surface of the substrate to preferentially dissolve certain desired areas of the substrate, resulting in unwanted damage created from prior processing steps (eg, , Removing crystal damage due to the implantation process), more evenly distributing the dopant in different regions of the substrate and / or activating different regions of the substrate. The preferential dissolution process allows for a more uniform distribution of the dopant in the dissolution region by increasing the diffusion rate and solubility of the dopant atoms in the dissolution region of the substrate. Thus, the creation of the dissolved region is: 1) redistributing the dopant atoms more uniformly, 2) removing the defects created in the pretreatment step, and 3) forming a region with a very abrupt dopant concentration. Make it possible. The gradient of dopant concentration in regions with very steep dopant concentrations is very large (eg <2 nm / decade concentration) as the concentration changes rapidly between device regions.

[0040] The use of the techniques described herein allows the formation of junctions that contain higher dopant concentrations than conventional devices, such as increased defect concentrations in the substrate material due to increased doping levels. This is because the general negative attributes of the formed junction can be easily reduced to acceptable levels by use of the processing techniques described herein. Higher dopant levels and drastic changes in dopant concentration can therefore increase the conductivity of various regions of the substrate, thus adversely affecting device yield while minimizing dopant diffusion to various regions of the substrate. Device speed can be improved without giving. The resulting higher dopant concentration increases the conductivity of the formed device and also improves this performance. Typically, devices formed using the RTP process do not use a dopant concentration greater than about 1 × 10 ¹⁵ atoms / cm ² , which means that a higher dopant concentration is present in the bulk material of the substrate during a normal RTP process. This is because they cannot be easily diffused and will result in clusters of dopant atoms and other types of defects. Using one or more of the embodiments of the annealing process described herein, more dopant (up to 5-10 times more dopant, ie 1 × 10 ¹⁶ atoms / cm ² ) is desired It can be successfully incorporated into the substrate surface, because the area of the substrate is preferentially dissolved so that the dopant is more evenly distributed throughout the liquid before the liquefied area solidifies. It is.

  [0041] FIG. 1 illustrates an isometric view of one embodiment of the present invention in which an energy source 20 applies a large amount of energy to a defined region or annealing region 12 of a substrate 10 for annealing. It is adapted to preferentially dissolve certain desired regions within region 12. In one example, as shown in FIG. 1, only one or more defined regions of the substrate, such as annealing region 12, are exposed to radiation from energy source 20 at a given time. In one aspect of the invention, multiple areas of the substrate 10 are sequentially exposed to the desired amount of energy delivered from the energy source 20 to provide preferential dissolution of the desired area of the substrate. In general, the area on the surface of the substrate converts the substrate to the output of an electromagnetic radiation source (eg, a conventional X / Y stage, precision stage) and / or converts the output of the radiation source to the substrate. May be sequentially exposed. Typically, one or more conventional electrical actuators 17 (eg, linear motors, lead screws and servo motors) may be part of individual precision stages (not shown) and control the movement and position of the substrate 10. Used to do. A conventional precision stage and heat exchange device 15 that can be used to support and position the substrate 10 can be purchased from Parker Hanificin Corporation of Rohnart Park, California.

[0042] In one aspect, the annealing region 12 includes a die 13 (eg, 40 “dies” are shown in FIG. 1) or a semiconductor device (eg, memory chip) formed on the surface of the substrate. Is sized to match the size of. In one aspect, the boundaries of the annealing region 12 are aligned and sized to fit within a “kerf” or “scribe” line 10A that defines the boundary of each die 13. In one embodiment, prior to performing the annealing process, the substrate is aligned to the output of the energy source 20 using alignment marks and other conventional techniques typically found on the surface of the substrate, so that the annealing region 12 is It can be properly aligned with the die 13. Sequentially placing the annealing region 12 so that it overlaps only in the unused space / boundaries that naturally occur between the dies 13, such as scribe or kerf lines, overlaps the energy in the area where the device is formed on the substrate By reducing the need to reduce variability in process results between overlapping annealing regions. This technique has advantages over conventional processes that sweep laser energy across the surface of the substrate, but this is closely controlled by controlling overlap between adjacent scanned regions. This is because the need to ensure uniform annealing across the entire region is not a problem due to confinement of overlap in unused space between dies 13. Confinement of overlap in unused space / boundaries between dies 13 also improves process uniformity results and conventional scan annealing type methods that utilize adjacent overlapping regions across the entire area of the substrate. Thus, process variations due to various amounts of exposure to energy delivered from the energy source 20 to process critical regions of the substrate are minimized, which is the delivered energy between the sequentially disposed annealing regions 12. This is because it is possible to minimize the duplication. In one embodiment, each of the sequentially disposed annealing regions 12 is a rectangular region having a size of about 22 mm × about 33 mm (eg, an area of 726 square centimeters (mm ² )). In one aspect, the area of each of the sequentially disposed annealing regions 12 formed on the surface of the substrate is about 4 mm ² (eg, 2 mm × 2 mm) to about 1000 mm ² (eg, 25 mm × 40 mm).

  [0043] The energy source 20 is generally adapted to deliver electromagnetic energy to preferentially dissolve certain desired areas of the substrate surface. Typical electromagnetic energy sources include, but are not limited to, optical radiation sources (eg, lasers), electron beam sources, ion beam sources, and / or microwave energy sources. In one aspect, the substrate 10 is exposed to a pulse of energy from a laser that emits at one or more suitable wavelengths for a desired period of time. In one aspect, the energy pulse from the energy source 20 is optimized so that the amount of energy delivered across the annealing region 12 and / or the amount of energy delivered during the pulse period enhances preferential dissolution of certain desired areas. To be adjusted. In one aspect, the wavelength of the laser is adjusted such that a substantial portion of the radiation is absorbed by the silicon layer disposed on the substrate 10. For laser annealing processes performed on silicon-containing substrates, the wavelength of radiation is typically less than about 800 nm and can be transmitted at deep ultraviolet (UV), infrared (IR) or other desired wavelengths. In one embodiment, the energy source 20 is a high intensity light source, such as a laser, adapted to deliver radiation at a wavelength of about 500 nm to about 11 micrometers. In either case, the annealing process generally occurs in a given area of the substrate in a relatively short period of time, for example, less than about 1 second.

  [0044] In one aspect, the amount of energy delivered to the surface of the substrate is configured such that the dissolution depth does not extend beyond the amorphous depth defined by the amorphization implantation step. A deeper dissolution depth facilitates diffusion of the dopant from the doped amorphous layer to the undoped dissolved layer. Such undesirable diffusion can significantly and detrimentally change the electrical characteristics of the circuit on the semiconductor substrate. In some annealing processes, energy is delivered to the surface of the substrate in a very short period of time to dissolve the surface of the substrate to a well-defined depth, eg, less than 0.5 micrometers. The exact depth is determined by the size of the electronic device being manufactured.

Substrate temperature control during the annealing process
[0045] In one embodiment, it is desirable to control the temperature of the substrate during heat treatment by placing the surface of the substrate 10 illustrated in FIG. 1 in thermal contact with the substrate support surface 16 of the heat exchange device 15. . The heat exchange device 15 is generally adapted to heat and / or cool the substrate prior to or during the annealing process. In this configuration, Applied Materials Inc. A heat exchange device 15 such as a conventional substrate heater available from Santa Clara, California may be used to improve the post-processing properties of the annealed regions of the substrate. In general, the substrate 10 is placed in an enclosed processing environment (not shown) of a processing chamber (not shown) containing a heat exchange device 15. The processing environment in which the substrate resides during processing may be evacuated or may contain a low partial pressure inert gas of undesirable gases during processing, such as oxygen.

  [0046] In one embodiment, the energy required to reach the melting temperature is minimized because the substrate may be preheated before performing the annealing process, which is caused by rapid heating and cooling of the substrate. Stress can be reduced, and in some cases, the defect density in the resolidification area of the substrate can be reduced. In one aspect, the heat exchange device 15 includes a resistive heating element 15A and a temperature controller 15C that are adapted to heat a substrate disposed on the substrate support surface 16. The temperature controller 15C communicates with a controller 21 (described later). In one aspect, it may be desirable to preheat the substrate to a temperature between about 20 degrees Celsius and about 750 degrees Celsius. In one aspect where the substrate is formed from a silicon-containing material, it may be desirable to preheat the substrate to a temperature of about 20 ° C to about 500 ° C.

  [0047] In another embodiment, internal diffusion due to energy applied to the substrate during the annealing process is reduced and / or increased post-melt regrowth rate, as described in connection with FIG. It may be desirable to cool the substrate during processing in order to increase the amorphization of various regions during processing. In one configuration, the heat exchange device 15 contains one or more fluid channels 15B and a cryocooler 15D that are adapted to cool a substrate disposed on the substrate support surface 16. In one aspect, a conventional cryocooler 15D in communication with the controller 21 is adapted to deliver cooling fluid via one or more fluid channels 15B. In one aspect, it may be desirable to cool the substrate to a temperature between about −240 ° C. and about 20 ° C.

  [0048] The controller 21 (FIG. 1) is generally designed to facilitate control and automation of the heat treatment techniques described herein and is typically a central processing unit (CPU) (FIG. Not shown), memory (not shown), and support circuitry (ie, I / O) (not shown). The CPU controls various processes and hardware (eg, conventional electromagnetic radiation detectors, motors, laser hardware) and these processes (eg, substrate temperature, substrate support temperature, amount of energy from the pulsed laser, It may be one of any form of computer processor used in an industrial setting for monitoring the detector signal. A memory (not shown) is connected to the CPU, and may be a random access memory (RAM), a read only memory (ROM), a floppy disk, a hard disk, or other form of digital storage such as local or remote. There may be one or more of the readily available memories. Software instructions and data can be encoded and stored in a memory that instructs the CPU. A support circuit (not shown) is also connected to the CPU to support the processor as is conventional. Support circuitry may include conventional caches, power supplies, clock circuits, input / output circuits, subsystems, and the like. A program (or computer instructions) readable by the controller determines which tasks can be performed on the substrate. Preferably, the program is software readable by the controller, and also the substrate position, the amount of energy delivered with each electromagnetic pulse, the timing of one or more electromagnetic pulses, the intensity and wavelength as a time function of each pulse, Code is included for monitoring and controlling the temperature of various areas of the substrate, and any combination thereof.

Selective dissolution
[0049] One or more processes in an attempt to minimize interdiffusion between various regions of the formed device, remove defects in the substrate material, and more evenly distribute the dopant in the various regions of the substrate. Steps are performed on various regions of the substrate to preferentially remelt these regions when exposed to energy delivered from an energy source during the annealing process. The process of modifying the properties of the first region of the substrate to dissolve preferentially over the second region of the substrate when exposed to approximately the same amount of energy during the annealing process is between the two regions. This will be described later as creating a melting point contrast. In general, substrate properties that can be modified to allow preferential dissolution of a desired region of the substrate include implanting, driving in and / or co-depositing one or more elements within the desired region of the substrate. And creating physical damage to the desired area of the substrate and optimizing the formed device structure to create a melting point contrast of the desired area of the substrate. Each of these modification processes will be reviewed in turn.

[0050] FIGS. 2A-2C illustrate cross-sectional views of the electronic device 200 at different stages of a device fabrication sequence incorporating one embodiment of the present invention. FIG. 2A shows a typical formed on surface 205 of substrate 10 having two doped regions 201 (eg, doped regions 201A-201B), such as source / drain regions of a MOS device, gate 215 and gate oxide layer 216. A side view of the electronic device 200 is illustrated. Doped regions 201 </ b> A- 201 </ b> B are generally formed by implanting a desired dopant material into surface 205 of substrate 10. In general, normal n-type dopants (donor type species) may include arsenic (As), phosphorus (P) and antimony (Sb), and normal p-type dopants (acceptor type species) are doped. Boron (B), aluminum (Al), and indium (In) introduced into the semiconductor substrate 10 in order to form the regions 201A to 201B may be included. FIG. 3A illustrates an example of the concentration of dopant material as a function of depth from the surface 205 to the substrate 10 (eg, curve C ₁ ) along a path 203 that extends through the doped region 201A. Doped region 201A has a junction depth D ₁ after the injection process, which is, the dopant concentration may be defined as a point to be lowered to a very small amount. 2A-2F are only intended to illustrate some of the various aspects of the present invention and may be formed using the various embodiments of the present invention described herein. It should be noted that the device type, structure type or device area is not restrictive. In one example, the doped region 201 (eg, a source or drain region in a MOS device) is located at the location of the gate 215 (eg, the gate of a MOS device) without departing from the scope of the invention described herein. It can move up and down. As the size of the semiconductor device decreases, the position and shape of the structural elements of the electronic device 200 formed on the surface 205 of the substrate 10 may change to improve device manufacturability and device performance. As shown in FIGS. 2A-2E, modification of only a single doped region 201A does not limit the scope of the invention described herein, and embodiments of the invention It should be noted that it is only intended to illustrate how it can be used in the manufacture of semiconductor devices.

  [0051] FIG. 2B shows that melting point contrast is created by selectively modifying the characteristics of individual regions (eg, modification area 210) of substrate 10, which in this case is a region containing a single doped region 201A. 2B is a side view of the electronic device 200 shown in FIG. 2A during an adapted process step. FIG. After performing the correction process, a melting point contrast will be created between the correction area 210 and the uncorrected area 211. In one embodiment, the modification process is the step of adding material to the layer while it is being deposited on the surface of the substrate, the incorporated material forming an alloy with the substrate material in the modification area 210. A step adapted to reduce the melting point of the region 202 of In one aspect, the incorporated material is added to the deposited layer during the epitaxial layer deposition process.

[0052] In another embodiment, the modification process includes injecting a material that is adapted to form an alloy with the substrate material to reduce the melting point of the region 202 in the modification area 210 ("" of FIG. 2B). A ”). In one embodiment, modification process, as shown in Figure 2B, is adapted to inject the alloy material to a depth D _2. FIG. 3B illustrates an example of the concentration of dopant material (eg, curve C ₁ ) and implanted alloy material (eg, curve C ₂ ) as a function of depth from surface 205 through substrate 10 along path 203. In one aspect, the substrate 10 is formed from a silicon-containing material, and usable implant alloy materials include, for example, germanium (Ge), arsenic (As), gallium (Ga), carbon (C), tin (Sn), and antimony ( Sb). In general, the alloy material may be any material that lowers the melting point of region 202 in modified area 210 relative to unmodified area 211 when heated when the substrate base material is present. In one aspect, the region of the silicon substrate is modified by the addition of about 1% to about 20% germanium to reduce the melting point between the modified and unmodified areas. Addition of these concentrations of germanium appears to reduce the melting point of the modified and uncorrected areas by about 300 ° C. In one embodiment, the region 202 formed in the silicon substrate contains germanium (Ge) and carbon (C), so that the Si _x Ge _y C _z alloy has a melting point of the region 202 relative to the unmodified area 211. Form to lower. In another aspect, the area of the silicon substrate is modified by the addition of less than about 1% arsenic to reduce the melting point between the modified and unmodified areas.

[0053] In another embodiment, the modification process causes these damage by causing some damage to the material of the substrate 10 in various modification areas (eg, modification area 210), thereby damaging the crystal structure of the substrate. Including making the region more amorphous. Causes damage to the crystal structure of the substrate, such as damage to the single crystal silicon substrate, by reducing the melting point of this region relative to the undamaged region due to changes in the bonding structure of the substrate atoms. Causes thermodynamic property differences between regions. In one aspect, the damage to the correction area 210 in FIG. 2B is performed by impacting a projectile that may create damage to the surface of the substrate against the surface 205 of the substrate 10 (see “A” in FIG. 2B). Is done. In one aspect, the projectiles are silicon (Si) atoms that are implanted into the silicon-containing substrate to cause damage to the region 202 in the modification area 210. In another aspect, the damage to the substrate material is caused by surface gas atoms such as argon (Ar), krypton (Kr), xenon (Xe) or nitrogen (N ₂ ) using an implantation process, ion beam or bias plasma. And causing damage to the area 202 of the correction area 210. In one embodiment, modification process, as shown in Figure 2B, is adapted to create a region 202 that caused the damage to a depth D _2. It is believed that a transition or empty density of about 5 × 10 ¹⁴ to about 1 × 10 ¹⁶ / cm ² can be useful in creating a melting point contrast between the modified area 210 and the unmodified area 211. In one aspect, FIG. 3B illustrates an example of the concentration of dopant material (eg, curve C ₁ ) and defect density (eg, curve C ₂ ) as a function of depth from surface 205 along path 203 through substrate 10. ing.

  [0054] FIGS. 2A-2B illustrate a process sequence in which the modification process is performed after the doping process, but this process sequence does not limit the scope of the invention described herein. It should be noted. For example, in one embodiment, it may be desirable to perform the modification process described in FIG. 2B before performing the doping process described in FIG. 2A.

[0055] FIG. 2C illustrates a side view of the electronic device 20 shown in FIG. 2B exposed to radiation “B” emitted from an energy source, such as optical radiation from a laser. During this step, a correction area (eg, correction area 210) and an uncorrected area (eg, 211) disposed on the substrate 10 is a pulse of radiation “B” while the uncorrected area 211 remains solidified. Is applied to a large amount of energy that selectively dissolves and resolidifies the region 202 in the correction area 210. The amount of energy, energy density, and period of time during which radiation “B” is applied depends on the desired depth of region 202, the material used to create region 202, other materials used to form electronic device 200, and the formation By knowing the heat transfer characteristics of the components in the fabricated electronic device 200, the region 202 can be set to preferentially dissolve. As shown in FIGS. 2C and 3C, upon exposure to radiation “B”, the re-dissolution and re-solidification of region 202 results in the concentration of dopant atoms (eg, curve C ₁ ) and alloys (eg, curve C ₂ ). Are more evenly redistributed in region 202. Also, the dopant concentration between the region 202 and the substrate bulk material 221 has a well-defined boundary (ie, a “very abrupt” junction), thus minimizing unwanted diffusion into the substrate bulk material 221. In this embodiment described above where damage is caused to the substrate 10 to improve melting point contrast, the concentration of defects after resolidification (eg, curve C ₂ ) is preferably reduced to a very low level.

Thermal separation technology
[0056] In another embodiment, the various thermal properties of different regions of the formed device are adjusted to preferentially cause dissolution between regions. In one aspect, the melting point contrast is created by forming different regions of the device with materials having different thermal conductivities (k). It should be noted that the heat transferred by conduction is determined by the following formula:
Q = kAΔT / Δx
Where Q is the time rate of heat flow through the body, k is a conductivity constant that depends on the nature of the material and the material temperature, A is the area through which heat flows, and Δx is the current through which heat passes. The thickness of the main body, and ΔT is the temperature difference during heat transfer. Thus, since k is a material property, the selection and modification of materials in various regions of the substrate can control the heat flow to different regions of the substrate and increase the melting point contrast of these various regions. In other words, if the material in one area of the substrate has a higher thermal conductivity than the material in the other area, it will lose more thermal energy due to conduction loss during the laser annealing process and hence lower thermal conductivity It does not reach the same temperature that another region with has reached. Regions that are in intimate contact with higher heat transfer areas can be prevented from dissolving, while other areas in close contact with lower heat transfer regions are in the laser annealing process. The melting point will be reached. By controlling the thermal conductivity of various regions of the electronic device 200, the melting point contrast can be increased. The creation of regions having various thermal conductivities is performed by performing conventional deposition, patterning and etching techniques on the various underlayers of electronic device 200 to create these regions having different thermal conductivities. May be. Underlayers having different thermal conductivities may be formed using conventional chemical vapor deposition (CVD) processes, atomic layer deposition (ALD) processes, implantation processes, and epitaxial deposition techniques.

[0057] FIG. 2D illustrates a side view of an electronic device 200 having a buried region 224 that has a lower thermal conductivity than the substrate bulk material 221. FIG. In this case, the radiation “B” emitted from the energy source is absorbed by the surface 205 of the substrate and conducted through the substrate 10, so that the heat flow (Q in the region (eg, doped region 201A) on the buried region 224). ₁ ) is less than the amount of heat (Q ₂ ) from an area that does not have a buried layer with low conductivity. Therefore, this area is at a higher temperature than the other regions of the device because less heat is lost from the region above the buried region 224 than the other regions of the substrate. By controlling the amount of energy delivered by the energy source 20, the temperature of the region on the buried layer can be raised to a level that preferentially dissolves between other regions. In one aspect, the buried region 224 is formed from an insulating material such as silicon dioxide (SiO ₂ ), silicon nitride (SiN), germanium (Ge), gallium arsenide (GaAs), combinations thereof, or derivatives thereof. Although the actual melting point of the substrate material in the area to be dissolved is not changed, there is still a quantifiable and repeatable contrast in the thermal behavior from other areas of the substrate surface that allows it to be selectively dissolved. In another embodiment, the buried region 224 may have a higher conductivity than the substrate bulk material 221 so that areas that do not have a buried layer preferentially dissolve between regions on the buried layer. To.

Modification of surface properties
[0058] In one embodiment, the surface characteristics of the various regions 202 of the substrate 10 are altered to change the melting point contrast between one or more desired regions. In one aspect, the emissivity of the surface of the substrate in the desired area is varied to change the amount of energy transferred from the substrate surface during processing. In this case, regions with lower emissivity than other regions will achieve higher processing temperatures because they cannot re-radiate the absorbed energy received from the energy source 20. When performing an annealing process involving dissolution of the surface of the substrate, the processing temperature achieved at the surface of the substrate can be quite high (eg, up to 1414 ° C. for silicon), so the effect of changing the emissivity is It can also have a dramatic effect on melting point contrast because radiant heat transfer is the primary heat loss mechanism. Thus, variations in emissivity in different regions of the substrate surface can have a significant effect on the maximum temperature reached by various regions of the substrate. The low emissivity region may become higher than the melting point during the annealing process, while the high emissivity region absorbing the same amount of energy may remain substantially below the melting point. By changing the emissivity of various surfaces, ie emissivity contrast, selective deposition of low or high emissivity coatings on the substrate surface and / or modification of the substrate surface (eg surface oxidation, surface roughening) May be achieved.

  [0059] In one embodiment, the reflectivity of the surface of the substrate in one or more regions is varied to change the amount of energy absorbed when the substrate 10 is exposed to energy from an energy source. By changing the reflectivity of the surface of the substrate, the amount of energy absorbed, and hence the maximum temperature achieved by the substrate at and below the substrate surface, will vary based on the reflectivity. In this case, the surface with low reflectivity is easier to dissolve than another region with high reflectivity. Changing the reflectivity of the surface of the substrate can be achieved by selective deposition of a low or high reflective coating on the substrate surface and / or modification of the substrate surface (eg, surface oxidation, surface roughening). A superabsorbent (non-reflective) coating may be selectively applied to areas that are dissolved during the annealing process.

[0060] FIG. 2E illustrates an emissivity and / or reflection that is different from other areas of the surface 205 of the substrate 10, with the coating 225 being selectively deposited or evenly deposited and then selectively removed. FIG. 4 illustrates one embodiment that leaves a layer having a rate. In this case, the heat flow (Q ₁ ) of the doped region 201A under the coating 225 can be adjusted based on the properties of the coating and the energy (Q ₂ ) absorbed in other regions of the substrate. In this way, the heat lost from the coating 225 (Q ₃ ) or reflected can be changed relative to the heat lost from other regions (Q ₄ ). In one aspect, a carbon-containing coating is deposited on the substrate surface using a CVD deposition process.

[0061] FIG. 2F shows that a coating 226 that changes the optical properties (eg, emissivity, reflectivity) of the surface of the substrate is deposited on the surface of the substrate, eg, the device shown in FIG. FIG. 4 illustrates one embodiment that is removed to create regions with different optical properties. For example, as shown in FIG. 2F, since the coating 226 has been removed from the surface of the gate 215, the surface of the coating 226 and the surface 205 of the gate remain exposed to incident radiation “B”. In this case, the coating 226 and the gate surface 205 have different optical properties such as different emissivities and / or different reflectivities. The removal process used to expose or create regions having different optical properties may be performed using a conventional material removal process such as a wet etch or chemical mechanical polishing (CMP) process. In this case, the absorption and heat flow of the doped regions 201A~201B under the coating 226 _{(Q 1)} includes a characteristic of the coating can be adjusted based on the absorption of the gate 215 region of the substrate and heat flow _{(Q 2).} Thus, the heat lost (Q ₃ ) reflected from the coating 226 can be altered relative to the heat lost (Q ₄ ) reflected from the gate 215 region.

  [0062] In one embodiment, the coating 226 modifies optical properties (eg, emissivity, absorptance, reflectivity) of various regions of the substrate that are exposed to incident radiation of one or more wavelengths, alone or in combination. Containing one or more deposited layers of a desired thickness. In one aspect, coating 226 contains a layer that preferentially absorbs or reflects one or more wavelengths of incident radiation “B” alone or in combination. In one embodiment, the coating 226 is made of fluorosilicate glass (FSG), amorphous carbon, silicon dioxide, silicon carbide, silicon carbon germanium alloy (SiCGe), nitrogen-containing silicon carbide (SiCN), Applied Materials, Inc. , Of BLOT ™ dielectric material made by processes commercially available from Santa Clara, or carbon deposited on the substrate surface using chemical vapor deposition (CVD) or atomic layer deposition processes (ALD) processes Contains dielectric materials such as containing coatings. In one aspect, the coating 226 contains a metal such as, but not limited to, titanium (Ti), titanium nitride (TiN), tantalum (Ta), cobalt (Co), or ruthenium (Ru).

  [0063] It should be noted that one or more of the various embodiments discussed herein can be used in conjunction with each other to further increase the process window. For example, a selectively deposited light absorbing coating may be used in connection with doping of certain defined areas to widen the process window of the annealing process.

Adjusting the energy source output to achieve preferential dissolution
[0064] As noted above, the energy source 20 is generally adapted to deliver electromagnetic energy to preferentially dissolve certain desired regions of the substrate 10. Typical electromagnetic energy sources include, but are not limited to, optical radiation sources (eg, lasers (wavelengths such as UV, IR)), electron beam sources, ion beam sources, and / or microwave energy sources. In one embodiment of the invention, the energy source 20 is adapted to deliver optical radiation, such as a laser, to selectively heat a desired area of the substrate to the melting point.

[0065] In one aspect, the substrate 10 is exposed to a pulse of energy from a laser that emits at one or more suitable wavelengths, and the emitted radiation is used to enhance preferential dissolution of certain desired regions. It has the desired energy density (W / cm ² ) and / or pulse duration. For laser annealing processes performed on silicon-containing substrates, the wavelength of radiation is typically less than about 800 nm. In either case, the annealing process generally occurs in a given area of the substrate in a relatively short period of time, for example, less than about 1 second. The desired wavelength and pulse profile used in the annealing process can be determined based on optical and thermal modeling of the laser annealing process in light of the material properties of the substrate.

  [0066] FIGS. 4A-4D illustrate the annealing process in which various attributes of the energy of a pulse delivered from the energy source 20 to the annealing 12 (FIG. 1) are adjusted as a function of time to achieve an improvement in melting point contrast. Fig. 4 illustrates various embodiments that improve results. In one embodiment, the shape of the laser pulse as a function of time and / or delivery energy is increased in order to increase the heat input to the area of the substrate to be melted and minimize the heat input to other areas. It is desirable to change the wavelength. In one aspect, it may also be desirable to change the energy delivered to the substrate.

[0067] FIG. 4A graphically illustrates a plot of delivered energy versus time for a single pulse of electromagnetic radiation (eg, pulse 401) that can be delivered from the energy source 20 to the substrate 10 (see FIG. 1). The pulses illustrated in FIG. 4A are generally rectangular pulses that deliver a certain amount of energy (E ₁ ) during the entire pulse period (t ₁ ).

  [0068] In one aspect, the shape of the pulse 401 can change as a function of time when delivered to the substrate 10. FIG. 4B graphically illustrates a plot of two pulses 401A, 401B of electromagnetic radiation that can be delivered from the energy source 20 to the substrate 10 having different shapes. In this example, each pulse may contain the same total energy output, as represented in the area under each curve, but the effect of exposing the region of the substrate 10 between the pulses is annealing. It may also improve the melting point contrast experienced during the process. Thus, the annealing process can be improved by adjusting the shape, peak power level and / or amount of energy delivered with each pulse. In one aspect, the pulse is Gaussian.

  [0069] FIG. 4C graphically illustrates one pulse of electromagnetic radiation (eg, pulse 401) having a trapezoidal shape. In this case, in two different segments of the pulse 401 (eg, 402 and 404), the delivered energy varies as a function of time. FIG. 4C illustrates the profile or shape of a pulse 401 that varies linearly in energy versus time, but is not intended to limit the scope of the present invention, which is the time variation of the energy delivered in the pulse. For example, it may have a forming curve of 2 degrees, 3 degrees or 4 degrees. In another aspect, the profile or shape of the energy delivered in pulses as a function of time may be a quadratic, cubic or exponential shape curve. In another embodiment, different shaped pulses (eg, rectangular and triangular modulation pulses, sine and rectangular modulation pulses, rectangular, triangular and sine modulation pulses, etc.) are processed during the process to achieve the desired annealing results. It would be convenient to use.

  [0070] Depending on the characteristics of various regions of the device, the shape of the emitted single pulse of electromagnetic radiation can be adjusted to improve the annealing process results. Referring to FIG. 4B, for example, the shape is similar to pulse 401B in situations where the various regions of the substrate that are melted during the annealing process are thermally isolated from other regions of the device by areas with low thermal conductivity. The use of a pulse is advantageous. Longer duration pulses are advantageous, because the more thermally conductive material region of the substrate takes more time to dissipate heat due to conduction, whereas the melted region is more thermal. This is because it is allowed to allow the temperature of the region separated and dissolved to reach the melting point temperature. In this case, the duration of the pulse, the peak power level and the total energy output of the pulse can be selected appropriately so that the undissolved area does not reach the melting point. The process of adjusting the shape of the pulse may also be advantageous when different emissivity surfaces are used to create the melting point contrast.

[0071] Referring to Figure 4C, in one embodiment, the slope of the segment 401, segment 401 shape, the shape of the segment 403, in the power level time (e.g., segment 403 at the energy levels _{E 1),} a segment 404 The slope and / or the shape of the segment 404 is adjusted to control the annealing process. It should be noted that it is generally undesirable to evaporate material in the annealing region during processing due to particle and process result variability considerations. Therefore, it is desirable to adjust the shape of the energy pulse and rapidly bring the temperature of the annealing region to the melting point without overheating the region and causing material evaporation. In one embodiment, as shown in FIG. 4G, multiple segments (ie, segments 402, 403A, 403B, 403C, and 404) prevent annealing of material within the annealing region while the annealing region is The shape of pulse 401 can be adjusted to be used to rapidly melt and then keep the material in solution for a desired period of time (eg, t ₁ ). The length of time, segment shape, and duration of each of the pulse segments can vary with changes in size, dissolution depth, and material within the annealing region.

  [0072] In another aspect, multiple wavelengths of radiant energy are combined to improve energy transfer to a desired region of the substrate to achieve improved melting point contrast and / or improved annealing process results. May be. In one aspect, the amount of energy delivered by each of the coupled wavelengths is altered to improve the melting point contrast and improve the annealing process results. FIG. 4D illustrates an example where the pulse 401 contains two wavelengths that can deliver different amounts of energy to the substrate 10 per unit time to improve the melting point contrast and / or to improve the annealing process results. ing. In this example, the frequency F1 is applied to the substrate at a constant level during the pulse period, and the other frequency F2 is applied to the substrate 10 at a constant level over most of the period except for a portion that peaks during the pulse period. Is done.

  [0073] FIG. 4E graphically illustrates a plot of a pulse 401 having two sequential segments that deliver energy at two different frequencies F3 and F4. Thus, because different regions of the substrate can absorb energy at different rates and different wavelengths, pulses containing multiple wavelengths capable of delivering various amounts of energy, as shown in FIGS. 4D and 4E. Is advantageous to achieve the desired kneeling process results.

  [0074] In one embodiment, two or more pulses of electromagnetic radiation are delivered to the region of the substrate at different times, so that the temperature of the region of the substrate surface is easily controllable. FIG. 4F graphically shows a plot of two pulses 401A and 401B delivered at various distances at time intervals, ie, period (t), to selectively dissolve a region on the surface of the substrate. It is shown. In this configuration, the peak temperature reached by the region on the substrate surface can be easily controlled by adjusting the period (t) between subsequent pulses. For example, by shortening the period (t) between pulses, that is, the frequency, the heat delivered by the first pulse 401A is shorter in time to dissipate the heat before the second pulse 401B is delivered. This makes the peak temperature achieved at the substrate higher than when the period between pulses is increased. Thus, the energy and the melting temperature can be easily controlled by adjusting the period. In one aspect, each pulse alone does not contain enough energy to bring the substrate to the melting temperature, but it is desirable to ensure that the region 202 can reach the melting temperature by combining the pulses. The process of delivering multiple pulses, eg, two or more pulses, tends to reduce the thermal shock experienced by the delivery of substrate material and single pulse energy. A heat shock can lead to damage to the substrate and can generate particles that create defects in subsequent processing steps performed on the substrate.

[0075] Referring to FIG. 4F, in one embodiment, two or more energy sources, such as a laser, are operated sequentially to shape the thermal profile of the surface of the substrate as a function of time. For example, a laser or an array of lasers can deliver a pulse 401A that raises the surface of the substrate to a temperature T ₀ at time t ₁ . t ₁ before or during the completion of the second pulse 402B is delivered from a plurality of lasers operating from a second laser to the substrate temperature to the temperature T _1, or one behind the other in time t _2. The thermal profile can thus be shaped by controlling the energy of sequential pulses delivered from multiple lasers. This process has heat treatment benefits such as, but not limited to, dopant diffusion and applications that control the direction of dopant diffusion.

Electromagnetic radiation pulse
[0076] The following process controls can be used to deliver sufficient electromagnetic radiation (light) to the surface of a silicon-containing substrate or a substrate composed of another material that requires heat treatment.

  [0077] In one embodiment, two or more electromagnetic energy sources, such as a laser, are operated sequentially to shape the thermal profile of the surface to be heat treated, where the laser is operated to correct for interpulse energy variations. Is done. In one aspect, the source 20 schematically illustrated in FIGS. 1 and 9 includes two or more electromagnetics, such as an optical radiation source (eg, a laser), an electron beam source, an ion beam source, and / or a microwave energy source. Contains energy sources, but is not limited to these. Interpulse energy from devices such as pulsed lasers may have a percentage change for each pulse. Variations in pulse energy may not be accepted by the substrate thermal process. To correct for this pulse variation, one or more lasers send out pulses that increase the substrate temperature. An electronic controller (eg, controller 21 in FIG. 1) that is adapted to monitor the delivered pulse and the energy and rise time of the pulse being delivered is a thermal profile (eg, the substrate as a function of time). Calculate the amount of energy required to “trim” or adjust the (region temperature) to be within the process target and also deliver the final energy to a second small laser or small laser series to complete the heat treatment Used to command. Electronic controllers generally use one or more conventional radiation detectors to monitor the energy delivered to the substrate and / or the pulse wavelength. Small lasers may also have peak-to-peak variations in pulse output energy, but this error is delivered because each pulse delivers substantially less energy than the initial pulse (or pulses) at the beginning of the surface treatment. Is generally within process limits. The electronic controller is therefore adapted to ensure that the desired energy level is delivered during the thermal process by compensating for variations in the energy delivered by the pulses.

  [0078] In one aspect, the two or more energy sources described above also use monochromatic (wavelength) laser light in a color frequency bandwidth, multiple wavelengths, single or multiple spatio-temporal laser modes and deflection states May be realized.

  [0079] The power of the laser or lasers does not have an accurate spatiotemporal energy profile for delivery to the substrate surface. Therefore, a system that uses a microlens to shape the output of the laser is used to create a uniform spatial energy distribution on the substrate surface. The choice of glass type and shape of the microlens compensates for the thermal lens effect in the light train necessary to deliver pulsed laser energy to the substrate surface.

  [0080] High frequency fluctuations in pulse energy at the substrate surface, known as speckle, are created by adjacent regions of constructive and destructive phase interference of incident energy. Speckle compensation may include: a surface acoustic wave device that rapidly changes phase in the substrate such that the rapid variation is substantially faster than the heat treatment time of one or more laser pulses, and a laser Pulse addition of pulses and alternating deflection of laser pulses, eg delivery of multiple simultaneous or delayed pulses that are linearly deflected but have a deflection state (e-vector) in non-parallel conditions.

Thermal stabilization structure formed on patterned substrate
[0081] In one embodiment, as shown in FIGS. 5A-5C, a homogeneous layer (item 110 in FIG. 5B) is deposited on the surface of the substrate such that the surface of the substrate is an electromagnetic radiation source (not shown). ) To reduce the variation in depth and volume of the silicon region 112 to be dissolved when exposed to the electromagnetic energy 150 delivered from the device. Variations in the depth and volume of the dissolved area can be attributed to the mass density of the various areas of the patterned substrate, the absorption coefficient of the material on which the radiant energy acts, and various physical and thermal properties of the material (eg, thermal conductivity). , Heat capacity, material thickness) variation. In general, electromagnetic radiation sources are designed to deliver electromagnetic energy to the surface of the substrate to heat treat or anneal portions of the substrate surface. Conventional electromagnetic radiation sources may include, but are not limited to, optical radiation sources (eg, lasers), electron beams, ion beams, or microwave sources.

  [0082] Although the device structure formed on the surface 102 of the substrate 100 illustrated in FIGS. 5A-5C and 6A-6C is not intended to limit the scope of the invention described herein. This is because, for example, the silicon region 112 (eg, a source or drain region in a MOS device) of the feature 101 (eg, the gate of a MOS device) without departing from the scope of the invention described herein. This is because the position can be raised and lowered. As semiconductor device sizes shrink, the location and shape of device components formed on the surface of a substrate change to improve device manufacturability and device performance.

  FIG. 5A illustrates a cross-sectional view of the substrate 100 having a plurality of features 101 and silicon regions 112 formed on the surface 102 of the substrate 100. As shown in FIG. 5A, the surface 102 has a plurality of features 101 that are laterally spaced at various distances. In one aspect, feature 101 is a “gate” and silicon region 112 is a “source / drain region” that is used to form a metal oxide semiconductor (MOS) device on the substrate surface. In the configuration shown in FIG. 5A, the incident electromagnetic energy 150 acts on the surface 102 to cause the incident energy to be absorbed in a partial region of the surface 102 of the substrate, and in some cases to form a dissolution region 113. The physical, thermal and optical properties of various materials exposed to incident electromagnetic energy 150 determine whether various areas of surface 102 will dissolve upon exposure to delivery energy. If the feature 101 is a polysilicon gate, the absorbed energy from the laser at a wavelength <800 nm is absorbed by a silicon region 112 containing N-type or P-type doped silicon, such as found in the source or drain region of a MOS device. Seems to be much less than the energy produced. Thus, due to the heat capacity and thermal mass of feature 101 and their relative position with respect to silicon region 112, the electromagnetic energy 150 delivered in the area adjacent to feature 101 remains cooler due to the diffusion of heat from melting region 113. It appears to be. The loss of heat to the feature 101 affects the depth and / or volume of the melting region 113 because it reduces the energy available to form the melting region 113. Therefore, there is a need for a method that reduces variations in pattern density on the surface of the substrate.

  [0084] FIG. 5B illustrates a cross-sectional view of the substrate 10 having a plurality of features 101 formed on the surface 102 of the substrate 100, a silicon region 112, and a homogeneous layer 120. FIG. FIG. 5B is similar to FIG. 5A except for the addition of a homogeneous layer 120. In general, the homogeneous layer 120 is used to make the heat capacity of the surface 102 of the substrate 100 more uniform. In one embodiment, the material and thickness from which the homogeneous layer 120 is formed balances the heat capacity of the surface of the substrate and reduces the depth and / or depth of the melting region 113 by reducing the effects of various mass densities across the substrate surface. Or selected to reduce volume variation. In general, the material of the homogeneous layer 120 is selected so that it does not dissolve during the subsequent annealing process and can be selectively removed from the surface of the substrate after the annealing process has been performed. In one aspect, the homogeneous layer 120 is a material that is similar in composition to the material from which the feature 101 is formed, such as a polysilicon-containing material. In another aspect, the homogeneous layer 120 is a silicon carbide-containing material or metal (eg, titanium, titanium nitride, tantalum, tungsten).

[0085] Preferably, the thickness (eg, d ₁ ) of the homogeneous layer 120 is selected such that the heat capacity of the device structure is uniform. In one aspect, the thickness d ₁ of the homogeneous layer 120 is defined by the following formula:
d ₁ = (α ₁ ) ^0.5 × [d ₂ / ((α ₂ ) ^0.5 )]
here,
d ₂ = thickness of the feature 101 (see FIG. 5B)
α ₁ = k ₁ / (p ₁ C _p1 ) and α ₂ = k ₂ / (p ₂ C _p2 )
Where k ₁ is equal to the thermal conductivity of the material used to form the homogeneous layer, p ₁ is equal to the mass density of the material used to form the homogeneous layer 120, and C _p1 is equal to the homogeneous layer 120. Is equal to the heat capacity of the material used to form, k ₂ is equal to the thermal conductivity of the material used to form feature 101, and p ₂ is used to form feature 101. It is equal to the mass density of the material and C _p2 is equal to the heat capacity of the material used to form the feature 101.

FIG. 6A illustrates a series of method steps that can be used to form a homogeneous layer 120 on the surface 102 of the substrate 100. In step 190 shown in FIGS. 6A and 6B, the homogeneous layer 120 is formed by conventional vapor deposition (CVD), plasma CVD, atomic layer deposition (ALD), plasma ALD or spin coating type deposition processes, such as. A deposition process is used to deposit on surface 102 (eg, feature 101) of substrate 100. In step 192 shown in FIGS. 6A and 6C, the surface 102 of the substrate 100 containing the homogeneous layer 120 is planarized using a chemical mechanical polishing (CMP) process. In step 194 shown in FIGS. 6A and 6D, the homogeneous layer is then selectively used using a selective material removal process such as a wet etch or dry etch type process until the desired thickness d ₁ is achieved. Is etched. Next, a large amount of incident electromagnetic energy can be delivered to the substrate surface to provide uniform annealing / dissolution of the material contained in the dissolution region 113.

Absorbing layer on homogeneous layer
[0087] FIG. 5C is a cross-section of substrate 100 containing the device illustrated in FIG. 5B with additional layer 125 deposited thereon to adjust the optical properties of various regions on the surface of the substrate. FIG. In one aspect, layer 125 is added to improve the absorption of electromagnetic energy 150 delivered to various regions of substrate 100. In one embodiment, layer 125 is the same as coating 225 or layer 226 described above. As shown in FIG. 5C, the layer 125 is preferentially formed on the homogeneous layer 120 to improve the selectivity of the energy delivered to the silicon region 112. The desired thickness of the layer 125 may change as the wavelength of the transmitted electromagnetic energy 150 changes.

  [0088] Referring to FIGS. 6A-6G, in one embodiment, after performing steps 190-194, steps 196 and 198 can be used to form a selectively deposited absorber layer 125. . In step 196 shown in FIGS. 6E and 6F, layer 125 is deposited on feature 101 and homogeneous layer 120 formed in steps 190-194 above. In step 198 shown in FIGS. 6E and 6G, layer 125 is subjected to a material removal step, such as a planarization process, which is typically completed using a chemical mechanical polishing (CMP) process. Removed from the upper surface of the substrate. In one aspect, the deposited layer 125 is used to change the melting point contrast between the desired region or regions on the substrate surface by absorbing and transmitting different amounts of heat to the region between the dissolution region 103 and the dissolution region. These regions are not in direct contact with the layer 125 and the homogeneous layer 120.

Diffraction grating
[0089] The problem that arises when features of different sizes, shapes, and spacings are exposed to electromagnetic radiation is that the amount of energy applied to the feature, depending on the wavelength of the electromagnetic radiation, is the energy delivered to the desired region That is, constitutive or destructive interference can be experienced due to diffraction effects that undesirably change the amount or energy density (eg, Watts / m ² ). Referring to FIG. 7, the spacing of the features 101 may be different so that the wavelength of incident radiation varies across the surface, resulting in a variation in energy density delivered across the surface 102 of the substrate 100.

  [0090] In one embodiment, as shown in FIG. 7, a layer 726 is grown to a thickness that exceeds all the height of the feature 101 to form a device (eg, Reduce diffraction effects created at irregular intervals between features 101). In one aspect, although not shown, the surface 720 of the layer 726 is further planarized (eg, a CMP process) to reduce intrinsic shape variations of the surface 720 of the substrate 10. Generally, the peak / valley variation across the surface of the substrate (<1 / 4λ) less than about a quarter of the wavelength of energy delivered during the annealing process (see FIG. 7 "PV"). It is also desirable to have an average period (see “PP” in FIG. 7) between peaks across the surface of the substrate that is greater than about 5 times the wavelength of energy delivered during the annealing process (eg,> 5λ). In one example, when using an 800 nm wavelength laser source, it is desirable to reduce the intrinsic shape variation of surface 720 to a period between peak / valley variation of less than about 200 nm and peak variation of greater than about 4000 nm. In one aspect, layer 726 is a carbon layer deposited by a CVD deposition process, or the materials discussed in connection with layer 125, coating 225, and layer 226 described above.

  [0091] In one embodiment, the design of the device formed on the surface of the substrate exposed to incident electromagnetic radiation is such that the desired diffraction pattern is created to improve the melting point contrast between different zones. Designed and arranged. The physical arrangement of the various features is thus adjusted for one or more desired wavelengths of the incident radiation “B” (FIG. 7) used to anneal the surface of the substrate.

Formation of amorphous regions on the substrate
[0092] In one embodiment, one or more processing steps are performed to selectively form amorphous regions 140 with the original single crystal or polycrystalline material to create damage during subsequent implantation processing steps. Reduce the amount and increase the melting point contrast of the amorphous region 140 relative to other areas of the substrate. Dopant implantation into amorphous regions such as amorphous silicon layers homogenizes the desired dopant implantation depth with fixed ion energy because of the lack of density variation across the various planes found in crystal lattice structures (eg single crystal silicon) Tend to. Amorphous layer implantation tends to reduce the crystal damage normally seen in conventional implantation processes in crystalline structures. Thus, if the amorphous region 140 is subsequently redissolved using an annealing type process as described above, the formed region can be recrystallized to have a more homogeneous doping profile and fewer defects. The remelting process also removes the damage created from the injection process. Formation of the amorphous region 140 also reduces the melting point of the affected region, which can therefore improve the melting point contrast between the amorphous region 140 and the adjacent single crystal region 141.

  [0093] In one embodiment, a small dose of energy (item “B” in FIG. 8) is delivered to the substrate 10 to selectively modify and form an amorphous silicon layer in a desired region (eg, amorphous region 140). To do. In one aspect, a pulse or dose of electromagnetic energy is delivered to the desired region with a fairly short period of time, resulting in rapid dissolution and cooling of the affected amorphous region 140, creating an amorphous region in the substrate. In this case, the energy of one pulse is a short period that can generate an amorphous region by generating a high regrowth rate of the heating region. In one aspect, the regrowth rate of the heated region is greater than about 12 m / sec.

[0094] In one aspect, a pulse of energy is ^{delivered to} a desired region of the silicon substrate with a period of less than about ^10-8 seconds. In this aspect, the energy of one pulse ^delivers a peak power in the range of about 10 ⁹ to about 10 ¹⁰ W / cm ² with a period greater than 10 ⁹ W / cm ² and preferably less than about 10 ⁻⁸ seconds. It may be delivered from a laser. In one aspect, the delivered dose power, pulse duration and shape to create the amorphous silicon layer may be varied to achieve an amorphous region 140 of the desired size, shape and depth. In one aspect, the wavelength of the delivered energy dose is selected or changed to achieve a desired dissolution profile. In one aspect, the wavelength may be a UV or IR wavelength. In one aspect, the wavelength of the laser may be less than about 800 nm. In another aspect, the wavelength may be about 532 nm or 193 nm.

  [0095] In one embodiment, a mask is used to preferentially form amorphous areas in various regions of the substrate surface.

Electromagnetic radiation transmission
[0096] FIG. 9 is adapted such that the energy source 20 delivers a large amount of energy from the back surface 901 to the annealing region 12 of the substrate 10 to preferentially dissolve certain desired regions within the annealing region 12. 2 is a cross-sectional view of a region of a processing chamber illustrating one embodiment. FIG. In one aspect, one or more defined regions of the substrate, such as annealing region 12, are exposed to radiation from energy source 20 at a given time. In one aspect, multiple areas of the substrate 10 are sequentially exposed to a desired amount of energy delivered from the energy source 20 via the backside surface 901 to provide preferential dissolution of desired regions of the substrate. In one aspect, the annealing region 12 is sized to match the size of a die (eg, item number 13 in FIG. 1) or semiconductor device formed on the top surface 902 of the substrate 10. In one aspect, the boundaries of the annealing region 12 are aligned and sized to fit within the “kerf” or “scribe” lines that define the boundaries of each die. Accordingly, the amount of process variation due to different amounts of exposure to energy from the energy source 20 is minimized because the overlap between the sequentially disposed annealing regions 12 can be minimized. In one example, the annealing region 12 is a rectangular region having a size of about 22 mm × about 33 mm.

  [0097] In one embodiment, the substrate 10 is positioned in a substrate support region 911 formed in the substrate support 910 having an opening 912 that causes the back surface 901 of the substrate 10 to receive energy delivered from the energy source 20. Yes. In this configuration, the radiation “B” emitted from the energy source 20 to heat the region 903 is adapted to absorb a portion of the radiant energy. The energy source 20 is generally adapted to deliver electromagnetic energy to preferentially dissolve certain desired areas of the substrate surface. Typical electromagnetic energy sources include, but are not limited to, optical radiation sources (eg, lasers), electron beam sources, ion beam sources, and / or microwave energy sources. In one aspect, the substrate 10 is exposed to energy pulses from a laser that emits at one or more suitable wavelengths for a desired period of time. In one aspect, the energy pulses from the energy source 20 are optimized for the amount of energy delivered across the annealing region 12 and / or the amount of energy delivered over the pulse period to enhance preferential dissolution of certain desired areas. To be adjusted. In one aspect, the wavelength of the laser is adjusted so that a substantial portion of the radiation is absorbed by the silicon layer disposed on the substrate 10. For laser annealing processes performed on silicon-containing substrates, the wavelength of radiation is typically less than about 800 nm, but can be transmitted at deep ultraviolet (UV), infrared (IR), or other desirable wavelengths. In either case, the annealing process generally occurs in a given area of the substrate in a relatively short time, such as on the order of less than about 1 second.

[0098] In one aspect, the wavelength of radiation from the energy source 20 is relative to incident radiation rather than the area near the upper surface 902 where the bulk material from which the substrate is formed is preferentially dissolved by exposure to incident radiation. Selected to be more transparent. In one aspect, the preferentially dissolved region is a high volume delivered through the back side of the substrate, such as dopant material or ionized crystal damage (eg, crystal defects, Frenkel defects, depletion) created during the implantation process. It contains materials that absorb the energy. In general, the dopant material may be boron, phosphorus, or other general purpose dopant materials used in semiconductor processing. In one embodiment, the bulk material from which the substrate is formed is a silicon-containing material and the wavelength of emitted radiation is greater than about 1 micrometer. In another aspect, the energy source 20 contains a CO ₂ laser is adapted to emit principal wavelength band to concentrate to approximately 9.4 to 10.6 micrometers. In yet another aspect, the energy source 20 is adapted to deliver a wavelength in the infrared region, which is generally between about 750 nm and about 1 mm.

  [0099] In one embodiment, an absorbing coating (not shown) is disposed in the annealing region of the substrate 10, so that incident radiation transmitted through the back side of the substrate is absorbed before passing through the substrate. It is possible. In one aspect, the absorbent coating is a metal, such as titanium, titanium nitride, tantalum, or other suitable metallic material. In another aspect, the absorbent coating is a silicon carbide material, an amorphous carbon material, or other suitable material commonly used in semiconductor device manufacturing.

[0100] In one embodiment, since the two wavelengths of light are delivered to the desired region of the substrate, the first wavelength of light is free of the substrate from dopants and other ionized crystal damage found in the desired annealing region. Used to generate carriers (eg, electrons and holes), the generated free carriers absorb energy transmitted through the back side of the substrate at the second wavelength. In one aspect, the first wavelength is a “green light” (eg, from about 490 nm to about 570 nm) wavelength and / or a shorter wavelength. In one embodiment, the first wavelength is the desired power density (W / cm ² ) and the desired area of the substrate from the second source 920 on the opposite side of the substrate from the energy source 20 shown in FIG. Is sent out. In another embodiment, two wavelengths (eg, first and second wavelengths) are emitted from source 20 through the back side of the substrate. In yet another embodiment, two wavelengths (eg, first and second wavelengths) of the desired power density (W / cm ² ) are passed through the back side of the substrate through two separate electromagnetic radiation sources (not shown). Is sent from.

  [0101] While the above is directed to embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, which scope is determined by the following claims. The

FIG. 4 illustrates an isometric view of an energy source that is adapted to deliver a large amount of energy to a defined area of the substrate described in the embodiments herein. FIG. 4 illustrates a schematic side view of a region on the surface of a substrate described in the embodiments herein. FIG. 4 illustrates a schematic side view of a region on the surface of a substrate described in the embodiments herein. FIG. 4 illustrates a schematic side view of a region on the surface of a substrate described in the embodiments herein. FIG. 4 illustrates a schematic side view of a region on the surface of a substrate described in the embodiments herein. FIG. 4 illustrates a schematic side view of a region on the surface of a substrate described in the embodiments herein. FIG. 4 illustrates a schematic side view of a region on the surface of a substrate described in the embodiments herein. FIG. 2D illustrates a concentration versus depth graph for the region of the substrate illustrated in FIG. 2A within an embodiment herein. FIG. 2D illustrates a concentration versus depth graph for the region of the substrate illustrated in FIG. 2B within an embodiment herein. FIG. 2D illustrates a concentration versus depth graph for a region of the substrate illustrated in FIG. 2C within an embodiment herein. FIG. 3 is a schematic diagram of electromagnetic energy pulses described in the embodiments herein. FIG. 3 is a schematic diagram of electromagnetic energy pulses described in the embodiments herein. FIG. 3 is a schematic diagram of electromagnetic energy pulses described in the embodiments herein. FIG. 3 is a schematic diagram of electromagnetic energy pulses described in the embodiments herein. FIG. 3 is a schematic diagram of electromagnetic energy pulses described in the embodiments herein. FIG. 3 is a schematic diagram of electromagnetic energy pulses described in the embodiments herein. FIG. 3 is a schematic diagram of electromagnetic energy pulses described in the embodiments herein. FIG. 4 illustrates a schematic side view of a region on the surface of a substrate described in the embodiments herein. FIG. 4 illustrates a schematic side view of a region on the surface of a substrate described in the embodiments herein. FIG. 4 illustrates a schematic side view of a region on the surface of a substrate described in the embodiments herein. FIG. 2 illustrates a method of forming one or more desired layers on the surface of a substrate described in the embodiments contained herein. FIG. 6D illustrates a schematic side view of a region of the substrate described in connection with the method illustrated in FIG. 6A (step 190) within the embodiments described herein. FIG. 6D illustrates a schematic side view of a region of the substrate described in connection with the method illustrated in FIG. 6A (step 192) within the embodiments described herein. FIG. 6D illustrates a schematic side view of a region of the substrate described in connection with the method illustrated in FIG. 6A (step 194) within the embodiments described herein. FIG. 2 illustrates a method of forming one or more desired layers on the surface of a substrate described in the embodiments contained herein. FIG. 7D illustrates a schematic side view of a region of the substrate described in connection with the method illustrated in FIG. 6E (step 196) within the embodiments described herein. FIG. 6D illustrates a schematic side view of a region of the substrate described in connection with the method illustrated in FIG. 6E (step 198) within the embodiments described herein. FIG. 4 illustrates a schematic side view of a region on the surface of a substrate described in the embodiments herein. FIG. 4 illustrates a schematic side view of a region on the surface of a substrate described in the embodiments herein. FIG. 6 illustrates a schematic side view of a system having an energy source adapted to dispense a large amount of energy to a defined area of a substrate as described in embodiments herein.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Board | substrate, 12 ... Annealing area | region, 13 ... Die, 15 ... Heat exchange device, 15A ... Resistance heating element, 15B ... Fluid channel, 15C ... Temperature controller, 15D ... Cryogenic cooler, 17 ... Electric actuator, 20 ... Energy source 21 ... Controller, 100 ... Substrate, 102 ... Surface, 112 ... Silicon region, 113 ... Dissolving region, 120 ... Homogeneous layer, 125 ... Layer, 140 ... Amorphous region, 150 ... Electromagnetic energy, 200 ... Electronic device, 201 ... Dope Region 202 202 region 203 path 205 surface modified 210 211 unmodified area 215 gate 216 gate oxide layer 221 substrate bulk material 224 buried region 225 226 ... coating, 401 ... pulse, 720 ... surface, 726 ... layer, 91 ... substrate support, 911 ... substrate supporting area, 912 ... opening

Claims (15)

A method of heat treating a substrate,
Modifying the one or more regions of the substrate formed from the first material by disposing a second material in the one or more regions, wherein the one of the substrates by the second material; Modifying the above regions is adapted to reduce the melting point of the first material contained in the one or more regions;
Disposing a third material in the one or more regions of the substrate;
Delivering a large amount of electromagnetic energy to a surface of a substrate in thermal communication with the one or more regions, wherein the large amount of electromagnetic energy dissolves the first material in the one or more regions. A step adapted to:   The method of claim 1, wherein the first material is selected from the group consisting of silicon, germanium, gallium arsenide, gallium phosphide, and gallium nitride.   The method of claim 1, wherein the first material is a silicon-containing material and the second material is selected from the group consisting of germanium, arsenic, gallium, carbon, tin, and antimony.   The method of claim 1, wherein the third material is selected from the group consisting of arsenic, phosphorus, antimony, boron, aluminum, and indium.   The method of claim 1, wherein the second material is selected from the group consisting of argon, krypton, xenon and nitrogen. A method of heat treating a substrate,
Providing a substrate having one or more first regions that have been modified, wherein the melting point of the material contained in each of the first regions is contained in a second region of the substrate; Melting at a lower temperature than the material, wherein each of the second region and the first region is generally adjacent to the surface of the substrate;
Depositing a coating on the surface of the substrate, the coating having a different absorption and reflection coefficient than the surface of the substrate;
Removing a portion of the coating from the surface of the substrate generally adjacent to each of the first regions or the second region;
Delivering a large amount of electromagnetic energy to an area on the surface of the substrate containing the one or more first regions and the second region, wherein the large amount of electromagnetic energy is the one or more of the one or more regions. Preferentially dissolving the material in the first region.   Modifying the first region includes disposing an alloy material within the material of the one or more first regions, the alloy material comprising germanium, arsenic, gallium, carbon, tin 7. The method of claim 6, wherein the method is selected from the group consisting of and antimony. A method of heat treating a substrate,
Positioning the substrate on a substrate support, the substrate having a plurality of features formed on a surface of the substrate containing a first region and a second region;
Depositing a coating on the first and second regions, wherein the material from which the coating is formed has a desired heat capacity;
Removing a portion of the coating such that the thickness of the coating in the first region has a desired thickness, the average heat capacity of the entire substrate surface after removing the portion of the coating Are generally uniform steps;
Delivering a large amount of electromagnetic energy to an area containing the first region and the second region, the large amount of electromagnetic energy dissolving the material in the first region; and How to prepare.   Modifying the first region includes disposing an alloy material within the material of the one or more first regions, the alloy material comprising germanium, arsenic, gallium, carbon, tin 9. The method of claim 8, wherein the method is selected from the group consisting of: and antimony. A method of heat treating a substrate,
Providing the substrate having a first feature and a second feature formed on a surface of the substrate, wherein the second feature includes a first region and a second region. And steps to
Positioning the substrate on a substrate support;
Depositing a coating on the first and second features;
Removing a portion of the coating such that the coating is disposed in the second region and the surface of the first feature is exposed;
Delivering a large amount of electromagnetic energy to an area containing the first feature and the second feature, wherein the large amount of electromagnetic energy is within the first region of the second feature. Dissolving the material.   Modifying the first region includes disposing an alloy material within the material of the one or more first regions, the alloy material comprising germanium, arsenic, gallium, carbon, tin 11. The method of claim 10, wherein the method is selected from the group consisting of and antimony.   At least a portion of the coating is composed of fluorosilicate glass (FSG), amorphous carbon, silicon dioxide, silicon carbide, silicon carbon germanium alloy (SiCGe), titanium (Ti), titanium nitride (TiN), tantalum (Ta), cobalt ( The method according to claim 10, comprising Co), ruthenium (Ru) or silicon carbonitride (SiCN). A method of heat treating a substrate,
Delivering a first amount of electromagnetic energy to a first region on the surface of the substrate, wherein the first amount of electromagnetic energy dissolves the substrate material in the first region; and Making the crystal substrate material amorphous;
Injecting a second material into the amorphous first region;
Delivering a second amount of electromagnetic energy to the first region, the second amount of electromagnetic energy dissolving the material in the first region.   Further heating the substrate support so that the substrate positioned thereon is brought to a temperature of about 20 ° C. to about 600 ° C. before the second electromagnetic energy is delivered to the surface of the substrate. 14. A method according to any one of claims 1, 6, 8, 10 and 13 comprising.   Cooling the substrate support so that the substrate positioned thereon is brought to a temperature of about −240 ° C. to about 20 ° C. before the second electromagnetic energy is delivered to the surface of the substrate. The method of claim 13, further comprising:

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