TW202331024A - Lamp filament having a pitch gradient and method of making - Google Patents

Abstract

Examples disclosed herein relate to a to a pitch gradient in a lamp filament, and a method of making. In one implementation, a lamp has a bulb filled with a gas. A filament is disposed within the bulb. The filament has a plurality of coils that include a first coil having a first point. The plurality of coils includes a second coil having a second point, and a third coil having a third point. The pitch gradient is defined by a first pitch between the second point and the first point, and a second pitch between the third point and the second point. The second pitch is greater than the first pitch. The second point is 360 degrees away from the first point. The third point is 360 degrees from the second point. A terminal coil is electrically coupled to at least the first coil, the second coil, and the third coil.

Description

Filament with pitch gradient and method of making same

Examples disclosed herein relate to pitch gradients in filaments and methods of making them.

In substrate processing chambers such as epitaxial deposition chambers, the quality of the deposited material depends inter alia on the uniformity of the substrate temperature. Control of the heat source is one way to affect the thermal distribution of the temperature across the substrate. Maintaining a consistent heat distribution across the substrate allows for greater uniformity in the material deposited on the substrate between routine maintenance procedures.

When the heat source is a conventional lamp, the control of the size, shape and angle of the heat source corresponds directly to the heat distribution and thus to the quality of the material deposited on the substrate. Conventional methods of increasing lamp life include optimizing the gas within the lamp, or changing the materials making up the filament or lamp envelope. When a new or replacement lamp is used, the replacement lamp introduces variations in heat distribution due to the differences between the used lamp and the replacement lamp. Replacing lamps can therefore affect the thermal uniformity distribution across the substrate, so additional measures need to be taken to ensure consistent heat distribution to ensure that material deposition is not adversely affected by lamp replacement.

Accordingly, there is a need for an improved heat lamp for a substrate processing chamber.

Disclosed herein is a method and apparatus for forming a pitch gradient in a filament for use in a heater lamp configured to heat a semiconductor substrate. In one example a lamp is provided having a gas filled bulb. A filament is disposed within the bulb. The filament has a plurality of coils, and the coils include a first coil having a first point. The plurality of coils includes a second coil with a second point and a third coil with a third point. The first point, the second point and the third point form a pitch gradient. The pitch gradient is defined by a first pitch between the second point and the first point and a second pitch between the third point and the second point. The second pitch is greater than the first pitch. The second point is 360 degrees away from the first point. The third point is 360 degrees away from the second point. The terminal coil is electrically coupled to at least the first coil, the second coil and the third coil.

In one example, a semiconductor processing chamber is provided having a lamp configured to provide heat to an interior volume of the semiconductor processing chamber. The lamp has a gas-filled bulb. The filament is arranged in the bulb, and the filament includes a plurality of coils. The plurality of coils includes a first coil with a first point, a second coil with a second point, and a third coil with a third point. The first point, the second point and the third point form a pitch gradient. The pitch gradient is defined by a first pitch between the second point and the first point and a second pitch between the third point and the second point. The second pitch is greater than the first pitch, and the second point is 360 degrees away from the first point. The third point is 360 degrees away from the second point. The terminal coil is electrically coupled to at least the first coil, the second coil and the third coil.

In one example, a method of forming a lamp includes disposing a filament in a gas-filled bulb, the filament including a plurality of coils. The method includes forming a pitch gradient at a first coil having a first point, a second coil having a second point, and a third coil having a third point. The pitch gradient is defined by a first pitch between the second point and the first point and a second pitch between the third point and the second point. The second pitch is greater than the first pitch. The second point is 360 degrees away from the first point, and the third point is 360 degrees away from the second point.

A filament for a heating lamp is disclosed herein. The filament has a pitch gradient configured to help reduce filament deformation, thereby helping to extend lamp life. The filament is made of a material that radiates light and heat when an electric current passes through it. The filament can be placed in a gaseous environment that further extends filament life. Lamps can provide radiation in the visible to near-infrared range. The substrate absorbs radiation from the lamp, increasing its temperature and the suitability of the deposited material. Advantageously, extending lamp life reduces the frequency of lamp replacement with replacement lamps, thereby reducing costs and helping to maintain heat distribution for longer periods of time.

Known lamps may have a substantially uniform spacing between adjacent coils of the filament so that the filament has no gradient. The heating and cooling of the filament wire deforms the wire slightly, and thousands of processing runs can deform the entire filament. Thus, conventional filaments tend to sag in the direction of gravity until adjacent coils touch, thereby eliminating the spacing between the coils and causing lamp failure. In contrast, the methods and apparatus disclosed herein provide a pitch gradient between a plurality of pitches in the filament. Thus, the pitch variation along the filament significantly extends the lifetime of the lamp by maintaining the pitch between adjacent coils as the filament is subjected to metal fatigue caused by heating and cooling. Advantageously, lamps utilizing the filaments disclosed herein can extend lamp life to twenty (20) to twenty five (25) percent longer than conventional lamps.

FIG. 1 shows a schematic cross-sectional view of an exemplary processing chamber 100 configured to process one or more semiconductor substrates, according to one embodiment. The processing chamber 100 may be used to process one or more substrates therein, including processes of depositing materials on the substrate 140, heating the substrate 140, etching the substrate 140, or combinations thereof. The processing chamber 100 includes chamber walls 148 and an array of radiant heat assemblies 104 for heating components such as a substrate support 110 disposed within the processing chamber 100 . Each radiant heat assembly 104 includes a lamp 200 (shown in FIG. 2 ) and a lamp mounting module 118 .

As process gases or vapors permeate the surface of the substrate 140 , the radiant heat assembly 104 heats the substrate support 110 and the substrate 140 , facilitating deposition of material onto the device side of the substrate 140 . As shown in FIG. 1 , an array of radiant heat assemblies 104 may be disposed below and/or above substrate support 110 .

The substrate support 110 includes the substrate support 115 and is positioned within the processing chamber 100 between a ceiling 108 (eg, a window), which may be a dome or any other shape, and an energy transmission member 156 (eg, a window). It can also be a dome or any other shape. The top plate 108 and energy transfer members 156 , together with the body 112 disposed between the top plate 108 and the energy transfer members 156 , generally define an interior volume 111 of the processing chamber 100 . The top plate 108 and/or the energy transmissive member 156 may be optically transparent (transmit at least 95% of the high energy radiant radiation) to the high energy radiant radiation. Additionally, the top plate 108 and the energy transfer member 156 may be made of quartz. Additionally, in one or more examples, an array of radiant heat assemblies 104 may be disposed above top plate 108 .

Radiant heat assembly 104 is configured to heat substrate 140 during processing. Accordingly, the radiant heat assembly 104 may heat the substrate 140 to a temperature in the range of about 200 degrees Celsius to about 1,600 degrees Celsius. Each radiant heat assembly 104 may be coupled to a power distribution board through which power is supplied to each radiant heat assembly 104 . The radiant heat assemblies 104 are positioned within an enclosure configured to be cooled during or after processing by, for example, using a cooling fluid introduced into channels between the radiant heat assemblies 104 .

The substrate 140 is transferred into the processing chamber 100 and positioned onto the substrate holder 110 through a load port (not shown) formed in the main body 112 . A process gas inlet 114 and a gas outlet 116 are provided in the main body 112 .

A robot (not shown) enters the processing chamber 100 to engage at least the underside of the substrate 140 and remove the substrate 140 therefrom through the loadport. A new substrate can then be loaded onto the lift pins 152 by the robot, and then the substrate holder 110 can be activated to place the substrate 140 disposed on the substrate holder 110 . The lift pins 152 may include enlarged heads that allow the lift pins 152 to hang from openings in the substrate support 110 when in the processing position. The substrate support 110 divides the interior volume of the processing chamber 100 into a process gas area above the substrate support 110 and a purge gas area below the substrate support 110 when in the processing position.

The substrate temperature is measured by a sensor configured to measure the temperature of the bottom of the substrate support 110 . The sensor may be a pyrometer (not shown) disposed in a port formed in an enclosure of a processing chamber (eg, processing chamber 100 ).

The process gas supplied from the process gas supply source 151 is introduced into the process gas region through the process gas inlet 114 formed in the sidewall of the main body 112 . The process gas inlet 114 is configured to direct process gas in a generally radially inward direction. In one or more examples, the process gas inlet 114 is a side gas injector. The side gas injectors are positioned to direct process gases across the surface of the substrate support 110 and/or the substrate 140 . During a film formation process for forming a film layer on a substrate 140 , the substrate support 110 is located in a process position adjacent to and at approximately the same height as the process gas inlet 114 . The process gas generally flows over the upper surface of the substrate 140 and/or the substrate support 110 . The process gas exits the process gas region through a gas outlet 116 located on the opposite side of the process chamber 100 from the process gas inlet 114 . Removal of process gases through the gas outlet 116 is assisted by a vacuum pump 157 coupled to the gas outlet 116 .

The processing chamber 100 includes a sensing device 160 . The sensing device 160 may be mounted to the lid 106 of the processing chamber 100 . Alternatively, the sensing device 160 may be mounted to an element (not shown) outside the processing chamber 100 . Additionally, sensing device 160 may receive sensor data corresponding to thermal radiation of a film on a target element (eg, a portion of substrate support 110 ). The sensing device 160 may determine the thickness of the film from the sensor data or transmit the sensor data to the controller 130, and the controller 130 is configured to determine the thickness of the film from the sensor data.

The target element may be at least a portion of the surface 143 of the substrate support 110 . The target element may be any portion of surface 143 that is not covered by substrate 140 during processing. For example, the target element may be the surface 143 of the edge region of the substrate support 110 . Alternatively, the target element may be the interior of the inner surface 113 .

During the deposition process, as material is deposited onto substrate 140 to form a film, material is also deposited on the target element. For example, in a deposition process, when material is deposited onto substrate 140 to form a film, material is also deposited on a target element, such as surface 143 or inner surface 113 of substrate support 110 . Furthermore, during the etching process, as material is removed from the substrate 140 to change the thickness of the film on the substrate 140, material is also removed from the film formed on the target element. For example, during an etch process, as material is removed from substrate 140 , material is also removed from the film formed on one or more of surface 143 and/or inner surface 113 of substrate support 110 at a corresponding rate. Therefore, the film thickness on the target element corresponds to the film thickness on the substrate 140 . Therefore, monitoring the thickness of the film on the target element allows monitoring the thickness of the film on the substrate 140 .

Sensing device 160 includes sensor 162 , angled mounting element 164 , mounting block 166 , mounting plate 168 and reflector 170 . Sensors 162 may include radiation thermometers, emissivity sensors, and/or pyrometers, among others. For example, sensor 162 may be a radiation thermometer and the sensor data may correspond to the intensity of thermal radiation of the film deposited on the target.

Angled mounting element 164, mounting block 166, mounting plate 168, and reflector 170 may each be separate elements. Alternatively, two or more of the angled mounting element 164, mounting block 166, mounting plate 168, and reflector 170 may be combined into a single element. For example, angled mounting element 164 may be part of mounting block 166 . Additionally, reflector 170 may be part of mounting plate 168 . Additionally or alternatively, mounting block 166 may be part of mounting plate 168 . One or more of angled mounting elements 164, mounting blocks 166, mounting plate 168, and/or reflector 170 may be omitted. For example, mounting block 166 may be omitted and angled mounting element 164 may be mounted directly to mounting plate 168 .

The sensor 162 is mounted on an angled mounting element 164 such that the sensor 162 is mounted at an angle relative to the surface of the target element. For example, sensor 162 may be mounted at an angle of about 0 degrees to about 90 degrees relative to the target element. In one or more examples, sensor 162 may be mounted at an angle greater than about 90 degrees relative to the target element.

The sensor 162 may include an optical system 171 and a detector 172 . Optical system 171 may include one or more lenses that focus energy within the thermal radiation signal emitted by the film onto the target element and onto detector 172 . Detector 172 is sensitive to radiation and generates sensor data corresponding to radiation within the thermal radiation signal. Detector 172 may respond to various wavelengths of light. For example, detector 172 may be responsive to energy radiated from a target element within a wavelength range of about 700 nm to about 1300 nm. As another example, detector 172 may be responsive to energy radiated from a target element at a wavelength less than about 700 nm or greater than about 1300 nm. The sensor data generated by detector 172 may be proportional to the energy radiated by the target element. The sensor data can be processed to determine or infer the temperature of the target element.

Mounting plate 168 may be used to mount sensing device 160 to cover 106 or another component such that sensing device 160 can receive thermal radiation signals from a target component within processing chamber 100 . Reflector 170 includes a reflective interior surface and directs the thermal radiation signal onto sensor 162 . As mentioned above, the reflector 170 may be part of the mounting plate 168 .

The processing chamber 100 includes a controller 130 to control the operation of the processing chamber 100 during processing. For example, the controller 130 is configured to control the flow of various precursor and process gases, as well as purge gases from a gas source, during different operations of a substrate processing sequence. As further examples, the controller 130 is configured to control ignition of the spot heating modules, supply of gas, lamp operation or other process parameters, and other controller operations. The controller 130 is used to control the operation of the processing chamber 100 . For example, controller 130 may control operation of radiant heat assembly 104 , gas supply 151 , vacuum pump 157 , and/or sensor 160 . Controller 130 may be configured to perform method 500 (see FIG. 5 ). The present disclosure contemplates that a controller (which may be similar to controller 130 ) that does not control processing chamber 100 may be configured to implement method 500 (see FIG. 5 ).

Controller 130 may include processor 132 , memory 134 , and support circuitry 136 for processor 132 and assist in controlling the components of processing chamber 100 . The controller 130 can be any of any form of general purpose computer processor that can be used in an industrial setting to control the various chambers and sub-processors. Memory 134 stores software (source code or object code) that can be executed or caused to control the operation of processing chamber 100 in the following manner. Memory 134 is non-transitory and may be readily accessible such as random access memory (RAM), read only memory (ROM), or any other form of digital storage, locally or remotely one or more in memory. Memory 134 contains instructions that, when executed by processor 132 , facilitate performance of method 500 (shown in FIG. 5 ).

To assist in controlling the processing chamber 100, the processor 132 may be any form of general purpose computer processor or general purpose central processing unit (CPU), such as a programmable logic controller (PLC), that may be used in an industrial setting to control Various chambers and subprocessors. Memory 134 is coupled to processor 132, and memory 134 can be one or more of readily available memories, such as random access memory (RAM), dynamic random access memory (DRAM), static RAM (SRAM), ), Synchronous Dynamic RAM (SDRAM (for example, DDR1, DDR2, DDR3, DDR3L, LPDDR3, DDR4, LPDDR4, etc.)), Read Only Memory (ROM), Disk Drive, Hard Drive, Pen Drive, or any other form of Local or remote digital storage. Support circuitry 136 is coupled to processor 132 to support the processor. The supporting circuits 136 may include caches, power supplies, clock circuits, I/O systems, subsystems, and so on. Charged species generation, heating, and other programs can be stored in memory 134, usually as software routines. Software routines may also be stored and or executed by a second CPU (not shown) located at the remote end of the processing chamber 100 controlled by the processor 132 .

Memory 134 (non-transitory computer-readable medium) is in the form of a computer-readable medium containing instructions that, when executed by processor 132, assist in the operation of processing chamber 100 and/or performance of method 500 ( See Figure 5). The instructions in memory 134 are in the form of a program product, such as a program, that implements the methods of the present disclosure. The code may conform to any of several different programming languages. In one or more examples, the present disclosure can be implemented as a program product stored on a computer-readable storage medium for use with a computer system. The program(s) of the program product define the functions of the embodiments (including the methods described herein). Illustrative computer-readable storage media include (but are not limited to): (1) non-writable storage media (such as read-only memory devices in computers (such as compact discs read by CD-ROM drives), flash memory , ROM chips, or any type of solid-state non-volatile semiconductor memory) on which information is permanently stored on non-writable storage media; and (2) writable storage media (such as magnetic disc or hard drive or any type of solid state random access semiconductor memory) on which changeable information is stored. Such a computer-readable storage medium, when loaded with computer-readable instructions that direct the functions of the methods described herein, is an embodiment of the present disclosure.

FIG. 2 is a front view of an exemplary lamp 200 that may be used in the processing chamber 100 shown in FIG. 1B , according to one embodiment. The lamp 200 has a base 204 , a dome 220 and a pin portion 214 . In one or more examples, the dome 220 can be a generally cylindrical shaped dome, where one end of the cylinder can have a hemispherical end. The lamp 200 may also have a tip 222 at one end of the dome 220 . In one or more examples, dome 220 is made of quartz or other suitable material.

Lamp 200 includes a filament 248 disposed within dome 220 . Filament 248 has an outer diameter 264 . Filament 248 is formed from wire 308 (shown in FIG. 3 ). The filament 248 includes a coiled portion 252 extending in the y-direction 270 inside the dome 220 . In other words, the coiled portion 252 of the filament 248 extends in the y-direction 270 aligned with the long axis of the lamp 200 . The coiled portion 252 is helical in nature, but may have other shapes. The filament 248 is connected to a ground wire 260 .

The pin portion 214 includes a first pin 234 and a second pin 238 (eg, a pair of pins). The first pin 234 and the second pin 238 are configured to couple to a pair of electrodes 240 disposed within the light mounting module 118 . Base 204 may include circuitry and other components needed to couple filament 248 and/or ground wire 260 to first pin 234 and second pin 238 . The first and second pins 234 , 238 are configured to deliver energy to the filament 248 .

A first length 272 of lamp 200 is defined between the distal end of tip 222 and the bottom of pin portion 214 (excluding pins 234 , 238 ). The height 276 of the tip 222 is less than 1mm. The first length 272 of the lamp 200 is between approximately 120 mm and 135 mm. In one or more embodiments, first length 272 is approximately 125 mm. In one or more embodiments, first length 272 is approximately 127 mm. The width 246 between the first leg 234 and the second leg 238 is between about 6 mm and about 8 mm. Dome 220 has an outer diameter 250 of between about 11 mm to about 17 mm. The outer diameter 264 of the coiled portion 252 of the filament 248 is between about 3 mm and about 7 mm. Other geometries can be considered for various applications.

In operation, electrical current is applied to the filament 248, causing the filament 248 to radiate light and heat. In one or more examples of the present disclosure, the filament is made of tungsten or other suitable conductor. The tungsten filament radiates infrared radiation at temperatures up to about 3,422°C. It should be understood that other metals may be used without departing from the scope of the present disclosure. Dome 220 (eg, a quartz bulb) is filled with at least one gas configured to extend the life of filament 248 . The gas may have a low level of reactivity, such as one or more noble gases. Other gases may also be present in the bulb. The gas reduces the rate at which the filament 248 decomposes, thus extending the life of the lamp 200 .

FIG. 3 shows a filament 248 suitable for use with the lamp 200 of FIG. 2 according to one embodiment. A portion of filament 248 has a pitch gradient 324 . An upstream terminal 326 and a downstream terminal 328 are shown. In one or more embodiments, the wire 308 of the filament 248 has a diameter 351 of less than or equal to about 0.05 mm. Filament 248 may be configured such that current flows into upstream terminal 326 and out of the filament through downstream terminal 328 coupled to ground 260 . Considering an imaginary line 302 extending parallel to the central axis 301, the pitch is defined as the center-to-center distance from a first point 303 on a line 308 intersecting the imaginary line to a second point 305 on the line 308 intersecting the imaginary line . A second point 305 on line 308 is approximately 360 degrees from first point 303 along the helical circumference of line 308 . Pitch is defined as the difference between two adjacent points (eg first point 303 and second point 305 ). Pitch gradient 324 is defined as the difference between two or more pitches (eg, the difference between the magnitudes of two or more pitches 314-322). For example, the pitch gradient 324 may be the difference between the first pitch 314 and the second pitch 316 , eg, the difference between the magnitude of the first pitch 314 and the magnitude of the second pitch 316 . Thus, the pitch gradient 324 may comprise the difference between three or more points, such as the difference between the first point 303 and the second point 305 , and the difference between the second point 305 and the third point 307 . Along the circumference of line 308 , third point 307 is about 360 degrees from second point 305 (eg, away from a radial distance) and about 720 degrees from first point 303 . It can be appreciated that other points are approximately 360 degrees from adjacent points on line 308 . Wire 308 extends from central axis 301 at a constant radius 312 forming a helical pattern along the length of central axis 301 .

A first pitch 314 is defined as the distance between the first point 303 and the second point 305 . The second pitch 316 is defined as the distance between the second point 305 and the third point 307 . A third pitch 318 is defined as the distance between the third point 307 and the fourth point 309 . The fourth pitch 320 and the fifth pitch 322 are similarly defined as the distance between adjacent points 309-313. In the example shown, first pitch 314 is less than second pitch 316 , and second pitch 316 is less than third pitch 318 . As such, the pitch gradient 324 of the filament 248 increases in a direction extending from the first point 303 to the sixth point 313 . Accordingly, the pitch gradient 324 increases from the first pitch 314 to the fifth pitch 322 such that each adjacent pitch increases in the direction of the pitch gradient 324 . Pitch gradient 324 may be linear or non-linear.

In an example, the pitch gradient 324 of the filament 248 increases in the direction of gravity. The first point 303 is closer to the base 204 than the tip 222 of the dome 220 . Conversely, the sixth point 313 is closer to the tip 222 of the dome 220 than the base 204 is. When the filament 248 is disposed in the lamp 200 , the first pitch 314 is adjacent to the base 204 and is smaller than the second pitch 316 , and the second pitch 316 is smaller than the third pitch 318 . The third pitch 318 is closer to the tip 222 than the first pitch 314 . Advantageously, the pitch gradient 324 helps to enable the filament 248 to maintain the integrity of the coiled portion 252 when the lamp 200 is installed in the radiant heat assembly 104 . In one or more examples, the integrity of the coiled portion 252 is maintained about 20% longer than conventional lamps (not shown).

The heating and cooling of the wire 308 may cause the coiled portion 252 of the filament 248 to deform after thousands of treatments. In known lamps, gravity exacerbates this deformation as the material of the wire 308 heats and cools, making the deformation even greater. This repeated deformation of the conventional filament caused by temperature changes and the gravitational force of the wire mass leads to failure of the conventional lamp. Advantageously, the pitch gradient 324 helps resist repeated stress-induced deformation by heating and cooling of the filament 248, thereby enabling the filament 248 to maintain its integrity. In one or more examples, first pitch 314 , second pitch 316 , and third pitch 318 may be substantially equal after about 20,000 to about 25,000 processing runs. In one or more examples, the first pitch 314 to the fifth pitch 322 are substantially equal after about 20,000 to about 25,000 processing runs.

As noted above, the pitch gradient 324 may increase in the direction of gravity. Thus, when the filament 248 is installed in the lamp 200 of the processing chamber 100 , the first point 303 is closer to the tip 222 of the dome 220 than the second point 305 . Thus, the first pitch 314 is closer to the substrate support 110 or the substrate 140 than the second pitch 316 or subsequent pitches 318 - 322 . When the filament 248 is installed in the lamp 200 of the processing chamber 100 , the first point 303 is farther from the tip 222 of the dome 220 than the second point 305 . Thus, the first pitch 314 is farther from the substrate 140 (and substrate support 115 ) than the second pitch 316 and subsequent pitches 318 - 322 .

In one or more examples, the ratio between the last pitch and the first pitch of the pitches 314-324 is between about 2.0 and about 2.3, such as between about 2.05 and about 2.25. In one or more examples, the ratio is between about 2.1 and about 2.15. In one or more examples, with point 303 closest to base 204 and point 313 closest to tip 222 , pitch 314 is between about 1.0 mm and about 1.5 mm, and pitch 322 is between about 2.0 mm and Between about 3.45mm. In one example, pitch 316 is approximately 1.125 times the length of pitch 314 . As such, pitch gradient 324 is greater than zero (0). In one or more examples, the pitch gradient 324 is defined as: 0.005mm<{( _Pn+2 - _Pn+1 )-(Pn ₊₁ - _Pn )}>0.125mm, where n is given by fixed point, and n+1 is the immediately adjacent point, and point n is closer to the base 204. In one or more examples, the pitch gradient 324 is defined as: 0.005mm<{( _Pn+2 - _Pn+1 )-( _Pn+1 - _Pn )}>0.166mm. For example, P _n may be pitch 314 , P _{n + 1} is pitch 316 , P _{n + 2} is pitch 318 , and the initial point may be point 303 .

In one or more examples, the gradient pitch 324 can be increased such that a given pitch P _n = P ₀ +(n*s), where n is the number of given pitches in a given pitch set, P ₀ is the first pitch in the sequence of pitches, and s is the step. The step(s) may be between about 0.005mm and about 0.166mm, such as about 0.0156mm, 0.020mm or about 0.125mm. In one or more examples, the step(s) may be equal to the initial pitch P ₀ . In this example, P ₀ may be a distance equal to pitch 314, and P _n may be any of pitches 314-322. As noted above, the pitch gradient 324 may increase in the direction of gravity. Advantageously, the filament 248 with the pitch gradient 324 can have a duty cycle that is 20% longer than conventional filaments, thereby extending the useful life of the lamp 200 . In one or more examples, pitch gradient 324 may increase between successive pitches by about 2% and about 6%, such as about 2%, 3%, 4%, 5%, or about 6%.

FIG. 4 is a flowchart of an exemplary method for forming the filament 248 shown in FIG. 3 . The method begins at operation 402, where a filament having a plurality of coils is formed. In one or more examples, the wire is formed by mixing materials and drawing the material through a die (eg, a forming orifice) to form wire 308 . The wire is wound on a mandrel, such as a cylindrical rod, to form filament 248 . In one or more examples, the filament 248 undergoes annealing to soften the wire and make the filament 248 uniform. After the filament 248 is formed, the mandrel is removed after the annealing process. The mandrel can be dissolved in acid that will not damage the filament 248 . In one or more examples, the mandrel is formed from a metallic material that is different from the material of wire 308 . In one or more examples, filament 248 is partially formed with coiled portion 252 and ground 260 .

At operation 404, a pitch is formed between each set of coils in the plurality of coils. In one or more examples, the pitch is formed in the mandrel, as described above. Wire 308 is wound on the mandrel to form a helical filament having a plurality of coils. A pitch is formed between each set of coils along a predetermined length of line 308 . According to the method disclosed herein, the pitch between two adjacent coil groups is different. For example, for a given point 305 - 307 of filament 248 , a first pitch 314 is formed between first point 303 and second point 305 . A second pitch 316 is formed between the second point 305 and the third point 307 . A continuous coil with a continuous pitch is formed. The continuous coil may include one or more of the coils with points 303-313, and/or the continuous coil may be coupled to the coils with points 303-313. Successive pitches are defined as: _Pn = _P0 + (n*s), where n is the number of given pitches in a given set of pitches, _P0 is the first pitch, and s is a step (for a positive real number). The terminal coils are formed by terminal pitches, such as pitch 322 . The terminal coil is electrically coupled to the first coil and all coils in filament 248 . In one or more examples, pitch gradient 324 increases by approximately 2% of first pitch 314 . In one or more examples, the pitch gradient 324 increases by approximately 6% of the first pitch 314 between the first coil and the terminal coil. The terminal coil is a coil including the sixth point 313 and all points at a distance of 180 degrees (π radians) or more therefrom. Arranged in lamp 200 as shown, the terminal pitch is closest to tip 222 of dome 220 .

Method 400 proceeds to operation 406 where a pitch gradient is formed between the pitches formed in operation 404 . In one or more examples, the pitch gradient 324 is formed by varying the plurality of pitches formed along the length of the mandrel. For example, in conventional filaments, each pitch between adjacent coils is substantially equal. In the disclosed method, the pitch gradient 324 is formed by engraving pitches within the mandrel such that no two pitches are equal. Therefore, the difference between adjacent pitches is also not equal in the direction of coil increase, eg, extending from the base 204 to the tip 222 . Furthermore, the filament is formed such that no two of the plurality of pitches 314-322 are equal. As noted above, pitch gradient 324 may increase in a substantially linear fashion.

At operation 408, a filament is installed in the lamp housing. Filament 248 may be attached to an lead-in wire (not shown) that is coupled to electrode 240 disposed within base 204 . In one example, the lead-in wire includes hooks at its ends that may be crimped onto or welded to the ends of the upstream terminal 326 and the downstream terminal 328 . In yet another example, wires 308 are directly coupled to circuitry within base 204 . A bulb (eg, dome 220 ) is placed over filament 248 and the bulb is filled with gas to form lamp 200 , as disclosed in detail above.

Although operations 402-406 are described above as distinct operations, it should be understood that two or more operations 402-406 may occur together or substantially simultaneously. For example, a pitch gradient can be formed in the mandrel. When the wire 408 is wound around the mandrel, the wire evolves around the mandrel every 2π (360 degrees) from the starting point of the first coil to form a coil, thereby forming a plurality of coils. A second coil was formed as the wire continued around the mandrel at 4π (720 degrees) from the starting point of the first coil. A pitch is formed between a point on the first coil and a point on the second coil. As the wire continues around the mandrel at 6π (1080 degrees) from the starting point of the first coil, a third coil is formed. The pitch gradient 324 is formed when the pitch formed between the third coil and the second coil is greater than the pitch formed between the second coil and the first coil. Operations 402-406 continue until the desired filament length is reached.

A method and apparatus for measuring and testing lamp dimensions of a three-dimensional printing filament are disclosed above. Advantageously, lamps having the filaments disclosed herein increase lamp life by slowing filament deformation due to metal fatigue caused by the filament heating and cooling under gravitational stress. Although the foregoing relates to specific embodiments, other embodiments can be conceived without departing from the substrate scope of the foregoing, and the scope of the foregoing is determined by the scope of the following claims.

100: processing chamber 104: Radiant heat components 106: cover 108: top plate 110: substrate support 111: Internal volume 112: subject 113: inner surface 114: Processing gas inlet 115: substrate support 116: Gas outlet 118: Lamp installation module 130: Controller 132: Processor 134: memory 136: support circuit 140: Substrate 143: surface 148: chamber wall 151: Gas supply source 152:Lift pin 156: Energy transmission components 157: Vacuum pump 160: Sensing device 162: sensor 164: Angled Mounting Elements 166: Installation block 168: Mounting plate 170: reflector 171: Optical system 172: Detector 200: lights 204: base 214: Pin part 220: dome 222: tip 234: The first pin 238: Second pin 240: electrode 246: width 248: Filament 250: outer diameter 252: Winding part 260: Ground wire 264: outer diameter 270: y direction 272: first length 276: height 301: Central axis 302: imaginary line 303: first point 305: The second point 307: The third point 308: line 309: The fourth point 312: constant radius 313: sixth point 314: first pitch 316: Second pitch 318: Third pitch 320: Fourth pitch 322: fifth pitch 324: pitch gradient 326:Upstream terminal 328: Downstream terminal 351: diameter 400: method 402-408: Operation 500: method

Disclosed herein is a method and apparatus for forming a pitch gradient in a filament for use in a heater lamp configured to heat a semiconductor substrate. For a more detailed understanding of the above described features exemplified herein, the disclosure, briefly summarized above, can be seen more particularly by reference to various specific embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the drawings illustrate examples only and therefore should not be considered limiting of the scope of the disclosure. Accordingly, the figures allow for other equivalent examples.

FIG. 1 shows a schematic cross-sectional view of an exemplary processing chamber configured to process one or more semiconductor substrates, according to one embodiment.

Figure 2 shows a front view of a lamp that may be used as a lamp in the process chamber of Figure 1, according to one embodiment.

Fig. 3 shows a filament suitable for the lamp of Fig. 2 according to one embodiment.

FIG. 4 is a flowchart of an exemplary method for forming the filament shown in FIG. 3 , according to one embodiment.

To aid in understanding, identical reference numbers have been used wherever possible to designate common identical elements. It is contemplated that elements and features of one example may be beneficially incorporated in other examples without further recitation.

Domestic deposit information (please note in order of depositor, date, and number) none Overseas storage information (please note in order of storage country, institution, date, and number) none

248: Filament

252: Winding part

260: Ground wire

301: Central axis

302: imaginary line

303: first point

305: The second point

307: The third point

308: line

309: The fourth point

312: constant radius

313: sixth point

314: first pitch

316: Second pitch

318: Third pitch

320: Fourth pitch

322: fifth pitch

324: pitch gradient

326:Upstream terminal

328: Downstream terminal

351: diameter

Claims (20)

A lamp comprising the steps of: a light bulb filled with a gas; A filament, the filament is arranged in the bulb, the filament includes a plurality of coils, the plurality of coils includes: a first coil having a first point, a second coil having a second point, A third coil, the third coil has a third point, the first point, the second point and the third point form a pitch gradient defined by: a first pitch between the second point and the first point, and a second pitch, the second pitch is between the third point and the second point, wherein the second pitch is greater than the first pitch, the second point is 360 degrees away from the first point, and the third point is 360 degrees away from the second point, and A terminal coil electrically coupled to at least the first coil, the second coil and the third coil. The lamp as described in Claim 1, the lamp further comprises: a pair of electrodes electrically coupled to the filament; and A pair of pins is electrically coupled to the pair of electrodes, and the pair of pins is configured to transmit energy to the filament. The lamp of claim 1, wherein the filament comprises a filament having a diameter less than or equal to about 0.05 mm. The lamp as recited in claim 1, wherein a length of the lamp is about 127 mm. The lamp as recited in claim 1, wherein the pitch gradient increases between about 2% of the first pitch and about 6% of the first pitch between the first coil and the terminal coil. The lamp as claimed in claim 1, the plurality of coils further comprising: a continuous coil, the continuous coil has a continuous pitch, and the continuous pitch is defined as: P _n = P ₀ + (n*s), where n is a quantity of a given pitch in a given set of pitches, P ₀ is the first pitch, s is a step, and the step is a positive real number. The lamp as recited in claim 6, wherein the terminal coil is electrically coupled to the continuous coil. A semiconductor processing chamber comprising: A lamp configured to provide heat to an interior volume of the semiconductor processing chamber, the lamp comprising: a light bulb filled with a gas; A filament, the filament is arranged in the bulb, the filament includes a plurality of coils, the plurality of coils includes: a first coil having a first point, a second coil having a second point, A third coil, the third coil has a third point, the first point, the second point and the third point form a pitch gradient defined by: a first pitch between the second point and the first point, and a second pitch, the second pitch is between the third point and the second point, wherein the second pitch is greater than the first pitch, the second point is 360 degrees away from the first point, and the third point is 360 degrees away from the second point, and A terminal coil electrically coupled to at least the first coil, the second coil and the third coil. The semiconductor processing chamber as described in Claim 8, the semiconductor processing chamber further comprising: a pair of electrodes electrically coupled to the filament; and A pair of pins is electrically coupled to the pair of electrodes, and the pair of pins is configured to transmit energy to the filament. The semiconductor processing chamber of claim 8, wherein the pitch gradient is between about 2% of the first pitch and about 6% of the first pitch between the first coil and the end coil Increase. A method of forming a lamp, the method comprising the steps of: forming a filament to be disposed within a bulb filled with a gas, the filament comprising a plurality of coils; A first coil of the plurality of coils having a first point, a second coil of the plurality of coils having a second point and a third of the plurality of coils having a third point A pitch gradient is formed between the coils, wherein the pitch gradient is defined by: a first pitch between the second point and the first point, and a second pitch, the second pitch is between the third point and the second point, wherein the second pitch is greater than the first pitch, the second point is 360 degrees away from the first point, And the third point is 360 degrees away from the second point. The method of claim 11, the method further comprising: forming a continuous coil disposed within the bulb and electrically coupled to the plurality of coils, wherein the continuous coil has a continuous pitch, the continuous coil The pitch is defined as: P _n = P ₀ + (n*s), where n is an amount of a given pitch in a given set of pitches, P ₀ is the first pitch, s is a step, the The step is a positive real number. As the method described in claim item 12, the method further includes the following steps: A terminal coil is formed, the terminal coil is at least electrically coupled to the first coil and the continuous coil. The method of claim 13, wherein the pitch gradient increases between about 2% of the first pitch and about 6% of the first pitch between the first coil and the terminal coil. The method of claim 11, wherein the forming step of the filament comprises the steps of: mixing materials and drawing the materials through a die to form a thread. The method of claim 15, wherein the forming step of the filament further comprises the step of: winding the wire around a mandrel to form a filament. The method of claim 16, wherein the mandrel is formed of a metallic material different from a material of the wire. The method of claim 17, further comprising the step of: dissolving the mandrel in an acid. The method according to claim 16, further comprising the step of: annealing the filament. The method as recited in claim 16, wherein the forming step of the pitch gradient comprises the step of using an engraved pitch engraved into the mandrel.

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