Patent Publication Number: US-2017362702-A9

Title: Independent radiant gas preheating for precursor disassociation control and gas reaction kinetics in low temperature cvd systems

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 13/175,499 (Attorney Docket No. 11249USD01), filed Jul. 1, 2011, and issued as U.S. Pat. No. 8,663,390 on Mar. 4, 2014, which is a divisional of U.S. patent application Ser. No. 11/937,388 (Attorney Docket No. 11249), filed Nov. 8, 2007, and issued as U.S. Pat. No. 7,976,634 on Jul. 12, 2011, which claims benefit of U.S. Provisional patent application Ser. No. 60/866,799 (Attorney Docket No. 11249L), filed Nov. 21, 2006, all of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     Embodiments of the present invention generally relate to preheating gases for a semiconductor fabrication process. More specifically, to preheating gases used in deposition and etch reactions on a semiconductor substrate, such as an epitaxial deposition process or other chemical vapor deposition process. 
     2. Description of the Related Art 
     Epitaxial growth of silicon and/or germanium-containing films has become increasingly important due to new applications for advanced logic and DRAM devices, among other devices. A key requirement for these applications is a lower temperature process so that device features will not be damaged during fabrication. The lower temperature process is also important for future markets where the feature sizes are in the range of 45 nm to 65 nm, and avoidance of the diffusion of adjacent materials becomes critical. Lower process temperatures may also be required for both substrate cleaning prior to growth of the silicon and/or germanium-containing epitaxial film and during selective or blanket growth of the epitaxial film. By selective growth, it is generally meant that the film grows on a substrate which includes more than one material on the substrate surface, wherein the film selectively grows on a surface of a first material of said substrate, with minimal to no growth on a surface of a second material of said substrate. 
     Selective and blanket (non-selectively grown) epitaxial films containing silicon and/or germanium, and strained embodiments of such epitaxial films, which are grown at temperatures of less than about 700° C., are required for many current semiconductor applications. Further, it may be desirable to have the removal of native oxide and hydrocarbons prior to formation of the epitaxial film accomplished at temperatures in the range of about 650° C. or less, although higher temperatures may be tolerated when the removal time period is shortened. 
     This lower temperature processing is not only important to forming a properly functioning device, but it minimizes or prevents the relaxation of metastable strain layers, helps to prevent or minimize dopant diffusion, and helps to prevent segregation of dopant within the epitaxial film structure. Suppression of facet formation and short channel effects, which is enabled by low temperature processing (low thermal budget processing), is a significant factor for obtaining high performance devices. 
     Current techniques for selective and blanket epitaxial growth of doped and undoped silicon (Si), germanium (Ge), SiGe, and carbon containing films, are typically carried out using reduced pressure chemical vapor deposition (CVD), which is also referred to as RPCVD or low pressure CVD (LPCVD). The typical reduced pressure process, such as below about 200 Torr, is carried out at temperatures above about 700° C., typically above 750° C., to get an acceptable film growth rate. Generally, the precursor compounds for film deposition are silicon and/or germanium containing compounds, such as silanes, germanes, combinations thereof or derivatives thereof. Generally, for selective deposition processes, these precursor compounds are combined with additional reagents, such as chlorine (Cl 2 ), hydrogen chloride (HCl), and optionally hydrogen bromide (HBr), by way of example. A carbon-containing silane precursor compound, for example methylsilane (CH 3 SiH 3 ), may be used as a dopant. In the alternative, inorganic compounds, such as diborane (B 2 H 6 ), arsine (AsH 3 ), and phosphine (PH 3 ), by way of example, may also be used as dopants. 
     In a typical LPCVD process to deposit an epitaxial layer on a substrate, precursors are injected into a processing region in a chamber by a gas distribution assembly, and the precursors are energized above the surface of a substrate in the chamber by irradiation of the precursors in the processing region, which is typically low wavelength radiation, such as in the ultraviolet and/or infrared spectrum. Plasma generation may also be used to dissociate the reactants. The substrate temperature is typically elevated to assist in adsorption of reactive species and/or desorption of process byproducts, and it is desirable to minimize the delta between the precursor temperature in the processing region and the substrate temperature in order to optimize the energization of the precursors and enhance the deposition or desorption process. 
     To enable a more efficient dissociation process, it is desirable to preheat the precursors prior to delivery to the processing region to enable faster and more efficient dissociation of the precursors above the substrate. Various methods to heat the precursors have been employed, but challenges remain in stabilizing the preheat temperature prior to energization above the substrate surface. For example, the precursor temperature may be elevated to a desired temperature at or before introduction to the gas distribution assembly, but the precursor temperature may be lowered by thermal losses in flowing through the gas distribution assembly and/or along the flow path to the processing region above the substrate. 
     Therefore, there is a need in the art for an apparatus and method to minimize the temperature range delta between the introduction temperature of precursors and the processing region, and an apparatus and method of preheating precursors at the gas introduction point that also minimizes heat loss prior to dissociation of the precursor. 
     SUMMARY OF THE INVENTION 
     Embodiments described herein relate to an apparatus and methods for delivering a process gas to a processing region within a chamber. 
     In one embodiment, a method of delivering a preheated precursor gas to a processing region in a chamber is provided. The method includes providing a precursor gas to a gas distribution assembly in communication with the processing region, heating the precursor gas at the point of introduction in the gas distribution assembly using a radiant energy source, and maintaining at least a portion of the heat provided to the precursor gas along a flow path defined between the point of introduction and the processing region. 
     In another embodiment, a gas distribution assembly is provided. The gas distribution assembly includes an injection block having at least one inlet to deliver a precursor gas to a plurality of plenums from at least two gas sources, a perforated plate bounding at least one side of each of the plurality of plenums, at least one radiant energy source positioned within each of the plurality of plenums to provide energy to the precursor gas from one or both of the at least two gas sources and flow an energized gas though openings in the perforated plate and into a chamber, and a coolant source in communication with the at least one radiant energy source, wherein the radiant energy sources are independently controlled in each of the plurality of plenums. 
     In another embodiment, a gas distribution assembly is provided. The gas distribution assembly includes an injection block having at least one inlet to deliver a precursor gas to a plurality of plenums from at least two gas sources, a perforated plate bounding at least one side of each of the plurality of plenums, at least one radiant energy source positioned within each of the plurality of plenums to provide energy to the precursor gas from one or both of the at least two gas sources and flow an energized gas though openings in the perforated plate and into a chamber, and a variable power source coupled to each of the radiant energy sources positioned within each of the plurality of plenums. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. 
         FIG. 1  is a schematic cross-sectional view of one embodiment of a deposition chamber. 
         FIG. 2  is a schematic top view of a portion of the deposition chamber shown in  FIG. 1 . 
         FIG. 3  is a schematic side view of one embodiment of a gas distribution assembly. 
         FIG. 4  is an isometric schematic view of another embodiment of a gas distribution assembly. 
         FIG. 5  is an isometric schematic view of another embodiment of a gas distribution assembly. 
         FIG. 6  is an isometric schematic view of another embodiment of a gas distribution assembly. 
     
    
    
     To facilitate understanding, identical reference numerals have been used, wherever possible, to designate identical elements that are common to the figures. It is also contemplated that elements disclosed in one embodiment may be beneficially utilized on other embodiments without specific recitation. 
     DETAILED DESCRIPTION 
       FIG. 1  is a schematic cross-sectional view of a deposition chamber  100  configured for epitaxial deposition, which may be part of a CENTURA® integrated processing system available from Applied Materials, Inc., of Santa Clara, Calif. The deposition chamber  100  includes housing structure  101  made of a process resistant material, such as aluminum or stainless steel, for example 316 L stainless steel. The housing structure  101  encloses various functioning elements of the process chamber  100 , such as a quartz chamber  130 , which includes an upper chamber  105 , and a lower chamber  124 , in which a processing volume  118  is contained. Reactive species are provided to the quartz chamber  130  by a gas distribution assembly  150 , and processing byproducts are removed from processing volume  118  by an outlet  138 , which is typically in communication with a vacuum source (not shown). 
     A substrate support  117  is adapted to receive a substrate  114  that is transferred to the processing volume  118 . The substrate support  117  is disposed along a longitudinal axis  102  of the deposition chamber  100 . The substrate support may be made of a ceramic material or a graphite material coated with a silicon material, such as silicon carbide, or other process resistant material. Reactive species from precursor reactant materials are applied to surface  116  of the substrate  114 , and byproducts may be subsequently removed from surface  116 . Heating of the substrate  114  and/or the processing volume  118  may be provided by radiation sources, such as upper lamp modules  110 A and lower lamp modules  1108 . 
     In one embodiment, the upper lamp modules  110 A and lower lamp modules  1108  are infrared (IR) lamps. Non-thermal energy or radiation from lamp modules  110 A and  1108  travels through upper quartz window  104  of upper quartz chamber  105 , and through the lower quartz portion  103  of lower quartz chamber  124 . Cooling gases for upper quartz chamber  105 , if needed, enter through an inlet  112  and exit through an outlet  113 . Precursor reactant materials, as well as diluent, purge and vent gases for the chamber  100 , enter through gas distribution assembly  150  and exit through outlet  138 . 
     The low wavelength radiation in the processing volume  118 , which is used to energize reactive species and assist in adsorption of reactants and desorption of process byproducts from the surface  116  of substrate  114 , typically ranges from about 0.8 μm to about 1.2 μm, for example, between about 0.95 μm to about 1.05 μm, with combinations of various wavelengths being provided, depending, for example, on the composition of the film which is being epitaxially grown. In another embodiment, the lamp modules  110 A and  1108  may be ultraviolet (UV) light sources. In one embodiment, the UV light source, is an excimer lamp. In another embodiment, UV light sources may be used in combination with IR light sources in one or both of the upper quartz chamber  105  and lower quartz chamber  124 . An example of UV radiation sources used in combination with IR radiation sources can be found in U.S. patent application Ser. No. 10/866,471, filed Jun. 10, 2004, which published on Dec. 15, 2005, as United States patent publication No. 2005/0277272, which is incorporated by reference in its entirety. 
     The component gases enter the processing volume  118  via gas distribution assembly  150 . Gas flows from the gas distribution assembly  150  and exits through port  138  as shown generally at  122 . Combinations of component gases, which are used to clean/passivate a substrate surface, or to form the silicon and/or germanium-containing film that is being epitaxially grown, are typically mixed prior to entry into the processing volume. The overall pressure in the processing volume  118  may be adjusted by a valve (not shown) on the outlet port  138 . At least a portion of the interior surface of the processing volume  118  is covered by a liner  131 . In one embodiment, the liner  131  comprises a quartz material that is opaque. In this manner, the chamber wall is insulated from the heat in the processing volume  118 . 
     The temperature of surfaces in the processing volume  118  may be controlled within a temperature range of about 200° C. to about 600° C., or greater, by the flow of a cooling gas, which enters through a port  112  and exits through port  113 , in combination with radiation from upper lamp modules  110 A positioned above upper quartz window  104 . The temperature in the lower quartz chamber  124  may be controlled within a temperature range of about 200° C. to about 600° C. or greater, by adjusting the speed of a blower unit which is not shown, and by radiation from the lower lamp modules  1108  disposed below lower quartz chamber  124 . The pressure in the processing volume  118  may be between about 0.1 Torr to about 600 Torr, such as between about 5 Torr to about 30 Torr. 
     The temperature on the substrate  114  surface  116  may be controlled by power adjustment to the lower lamp modules  1108  in lower quartz chamber  124 , or by power adjustment to both the upper lamp modules  110 A overlying upper quartz chamber  104 , and the lower lamp modules  1108  in lower quartz chamber  124 . The power density in the processing volume  118  may be between about 40 W/cm 2  to about 400 W/cm 2 , such as about 80 W/cm 2  to about 120 W/cm 2 . 
     In one aspect, the gas distribution assembly  150  is disposed normal to, or in a radial direction  106  relative to, the longitudinal axis  102  of the chamber  100  or substrate  114 . In this orientation, the gas distribution assembly  150  is adapted to flow process gases in a radial direction  106  across, or parallel to, the surface  116  of the substrate  114 . In one application, the process gases are preheated at the point of introduction to the chamber  100  to initiate preheating of the gases prior to introduction to the processing volume  118 , and/or to break specific bonds in the gases. In this manner, surface reaction kinetics may be modified independently from the thermal temperature of the substrate  114 . 
       FIG. 2  is a schematic top view of a portion of a deposition chamber  100  similar the chamber shown in  FIG. 1 , with the exception of the substrate  114  not being shown. A gas distribution assembly  150  is shown coupled to the housing structure  101 . The gas distribution assembly  150  includes an injection block  210  coupled to one or more gas sources  140 A and  140 B. The gas distribution assembly  150  also includes a non-thermal heating assembly  220 , which includes a plurality of radiant heat sources, such as IR lamps  225 A- 225 F disposed at least partially in the injection block  210 . The injection block  210  also includes one or more plenums  224   N  disposed upstream of the openings  158  of a perforated plate  154 , such as inner plenum  224   2  and outer plenums  224   1  and  224   3 , and the IR lamps  225 A- 225 F are disposed at least partially in the plenums  224   N . 
     Although six IR lamps are shown, the gas distribution assembly  150  may include more or less IR lamps. The IR lamps  225 A- 225 F may include halogen type lamps, or rapid thermal processing (RTP) lamps with a wattage between about 300 watts to about 1200 watts, depending on the intensity of the radiation needed for the particular process, and/or the number of IR lamps used with the gas distribution assembly  150 . In the embodiment shown, the IR lamps  225 A- 225 F are RTP style lamps having a wattage between about 500 watts to about 750 watts, for example between about 500 watts to about 550 watts with about an 80 volt power application. In one application, the power density provided by each of the IR lamps  225 A- 225 F may be between about 25 W/cm 2  to about 40 W/cm 2  in the plenums  224   N . In one embodiment, the IR lamps  225 A- 225 F provide a variable temperature in each plenum  224   N  of about 50° C. to about 250° C. 
     In operation, precursors to form Si and SiGe blanket or selective films are provided to the gas distribution assembly  150  from the one or more gas sources  140 A and  140 B. The gas sources  140 A,  140 B may be coupled the gas distribution assembly  150  in a manner configured to facilitate introduction zones within the gas distribution assembly  150 , such as an outer zone that is shown as outer plenums  224   1  and  224   3 , and an inner zone, shown as inner plenum  224   2 . The gas sources  140 A,  140 B may include valves (not shown) to control the rate of introduction into the plenums  224   N . Alternatively, the plenums  224   N  may be in communication with one gas source, or other gas sources may be added to create more introduction zones. 
     The gas sources  140 A,  140 B may include silicon precursors such as silanes, including silane (SiH 4 ), disilane (Si 2 H 6 ,), dichlorosilane (SiH 2 Cl 2 ), hexachlorodisilane (Si 2 Cl 6 ), dibromosilane (SiH 2 Br 2 ), higher order silanes, derivatives thereof, and combinations thereof. The gas sources  140 A,  140 B may also include germanium containing precursors, such as germane (GeH 4 ), digermane (Ge 2 H 6 ), germanium tetrachloride (GeCl 4 ), dichlorogermane (GeH 2 Cl 2 ), derivatives thereof, and combinations thereof. The silicon and/or germanium containing precursors may be used in combination with hydrogen chloride (HCl), chlorine gas (Cl 2 ), hydrogen bromide (HBr), and combinations thereof. The gas sources  140 A,  140 B may include one or more of the silicon and germanium containing precursors in one or both of the gas sources  140 A,  140 B. For example, the gas source  140 A, which may be in communication with the outer plenums  224   1  and  224   3 , may include precursor materials, such as hydrogen gas (H 2 ) or chlorine gas (Cl 2 ), while gas source  140 B may include silicon and/or germanium containing precursors, derivatives thereof, or combinations thereof. 
     The precursor materials from the gas sources  140 A,  140 B are delivered to the plenums  224   N  and the non-thermal energy from the IR lamps  225 A- 225 F illuminates the precursor materials with IR energy in the plenums  224   N  at the point of introduction. The wavelength of the non-thermal energy resonates and excites the precursor materials by taking advantage of the vibrational stretch mode of the precursor materials, and the energy is absorbed into the precursor materials, which preheats the precursor materials prior to entry into the processing volume. The injection block  210 , which contains the IR lamps  225 A- 225 F, is made of a material with high reflectivity, such as stainless steel, which may also include a polished surface to increase reflectivity. The reflective quality of the material for the injection block  210  may also act as an insulator to minimize heating of the injection block, thus increasing safety to personnel that may be in close proximity to the injection block  210 . In one embodiment, the injection block  210  comprises stainless steel and the interior surfaces of the plenums  224   N  are polished. In another embodiment, the injection block  210  comprises aluminum and the interior surfaces of the plenums  224   N  are polished. 
     The precursor materials enter the processing volume  118  through openings  158  in the perforated plate  154  in this excited state, which in one embodiment is a quartz material, having the openings  158  formed therethrough. In this embodiment, the perforated plate is transparent to IR energy, and may be made of a clear quartz material. In other embodiments, the perforated plate  154  may be any material that is transparent to IR energy and is resistant to process chemistry and other process parameters. The energized precursor materials flow toward the processing volume  118  through a plurality of holes  158  in the perforated plate  154 , and through a plurality of channels  152   N . A portion of the photons and non-thermal energy from the IR lamps  225 A- 225 F also passes through the holes  158 , the perforated plate  154 , and channels  152   N , facilitated by the high reflective material and/or surface of the injection block  210 , thereby illuminating the flow path of the precursor materials (shown as arrow  325  in  FIG. 3 ). In this manner, the vibrational energy of the precursor materials may be maintained from the point of introduction to the processing volume  118  along the flow path. 
     Intensity of the IR wavelengths in the plurality of IR lamps  225 A- 225 F may be increased or decreased depending on the process. In one application, intensity of the IR lamps may be controlled by filter elements  405  ( FIG. 4 ), and window  610  ( FIG. 6 ). In another embodiment, a sheath  315  ( FIG. 3 ) may be disposed over at least a portion of the IR lamps  225 A- 225 F, and the sheath may be configured as a filter element to control the intensity of the lamps. In one example, the filter elements may be a sleeve, sheet, or lens adapted to modulate bandwidth by selective transmission of specific wavelengths. The filter elements may be used on at least one of the IR lamps  225 A- 225 F or all of the IR lamps  225 A- 225 F. Alternatively, different filter elements may be used on different IR lamps  225 A- 225 F. In one example, the outer plenums  224   1  and  224   3  may receive a first level of intensity by using a first filter configured to absorb or block specific spectra, while the inner plenum  224   2  receives a second level of intensity by using a second filter configured to absorb or block a different specific spectra. 
     In another application that may be used alone or in combination with filters, the IR intensity in the multiple zones defined by the plenums  224   N  may be individually controlled by leads  226 A- 226 F coupled to a power source  205  and a controller. For example, the outer plenums  224   1  and  224   3  may receive a first level of intensity, while the inner plenum  224   2  receives a second level of intensity by variation of signals provided to the IR lamps  225 A- 225 F. Alternatively, each IR lamp  225 A- 225 F may be controlled separately by variation of signals provided by the controller. The intensity of the IR lamps  225 A- 225 F may be controlled in an open-loop mode, or a closed-loop mode. Thus, the precursor materials enter the processing volume  118  in a preheated or energized state, which may lessen the adsorption or desorption time frame or disassociation time, which, in turn, increases throughput. 
       FIG. 3  is a schematic side view of one embodiment of a gas distribution assembly  150  as shown in  FIGS. 1 and 2 . An aperture  305  is formed in the injection block  210  to receive a portion of an IR lamp  225 C, which is at least partially inserted into the plenum  224   2 . Precursor materials are supplied to the plenum  224   2  by a port  320  disposed in the injection block  210 . The aperture  305  may be sized slightly larger than the IR lamp  225 C to allow space for a sheath  315  adapted to encase a portion of the IR lamp  225 C. In one embodiment, the sheath  315  is made of a material transparent to IR energy, such as quartz, magnesium fluoride, calcium fluoride, sapphire, as examples. In another embodiment, the sheath  315  may be adapted as a filter element to modulate bandwidth by selective transmission of specific wavelengths. Temperature sensing devices (not shown), such as thermocouples, may be disposed in the injection block  210  to monitor the sheath temperature and/or the temperature in the plenum  224   2 . The aperture  305  also includes a larger diameter portion at the end opposite the plenum  224   2  to receive a high temperature seal  323 , for example an o-ring made of a polymeric material adapted to withstand elevated temperatures, such as a Teflon® material, polyethernitrile, polyetheretherketone (PEEK), polyaryletherketone (PAEK), among others. 
     Referring to  FIGS. 2 and 3 , the IR lamps  225 A- 225 F are coupled to a cooling device  310  to cool the IR lamps  225 A- 225 F. In one application, the cooling device  310  includes a conduit, such as a tubular member  156  having an inlet port  260 A and an outlet port  260 B, and is adapted to provide a coolant to a plurality of IR lamps  225 A- 225 F. In other embodiments (not shown in  FIGS. 2 and 3 ), the cooling device may be housing coupled to a single IR lamp. The cooling device  310  may comprise a cooling fluid, such as a liquid or gas from a coolant source  311  that circulates through the tubular member  156  to facilitate heat transfer from the IR lamps  225 A- 225 F. The tubular member  156  also includes apertures  306  adapted to receive a portion of the IR lamps  225 A- 225 F. At least one of the apertures includes a fitting  308 , such as a stainless steel VCO fitting, adapted to receive a portion of the IR lamp and seal the tubular member  156 . In one embodiment, the cooling fluid from the coolant source  311  is nitrogen gas, which is circulated through the tubular member  156 . 
     In operation, in reference to  FIG. 3 , precursor materials from gas source  140 B are introduced to the plenum  224   2  by the port  320 , and the precursor materials are radiantly heated by the IR lamp  225 C at this point of introduction. The lower partial pressure in the processing volume  118  (not shown in this view) creates a flow path  325  through the opening  158  and the channel  152   N . The precursor materials are energized in the plenum  224   2  and remain energized along the flow path  325  by the non-thermal energy reflected and/or passing into the channel  152   N . Thus, preheating of the precursor materials, and maintenance of the energized precursor materials, is enhanced. Using this non-thermal energy minimizes or eliminates the need for resistive or convective heating elements in or near the precursor introduction point, which may improve safety of the use of the chamber, and minimizes the need for extended cooling systems for the chamber. 
       FIGS. 4-6  are isometric schematic views of various embodiment of a gas distribution assembly  150  that may be coupled with the chamber  100  of  FIG. 1 . The gas distribution assembly  150  includes an injection block  210  having at least one IR lamp  425  in communication with a gas source, such as gas source  140 A and/or  140 B coupled to ports  320 . While not shown, each port is in communication with a plenum  224   N  disposed within the gas injection block  210 . In the embodiments depicted in  FIGS. 4-6 , each IR lamp  425  is individually coupled to the injection block  210  by a housing  410  that provides electrical connections (not shown) and cooling capabilities. In one embodiment, each housing  410  includes a port  415  that may be coupled to the coolant source  311  ( FIG. 3 ). In one application, each port  415  functions as an inlet and an outlet for cooling fluid. 
     In the embodiment shown in  FIG. 4 , a plurality of IR lamps  425  are disposed in a radial direction to the chamber  100  ( FIG. 1 ). In this embodiment, each IR lamp  425  is disposed normal to a gas injection path as defined by the directional orientation of the ports  320 . Additionally, one or more IR lamps  425  may include a filter element  405  adapted to modulate bandwidth by selective transmission of specific wavelengths from the IR lamp  425 . The filter element  405  may be a sheath, a plate, a sheet, or any article or device adapted block specific wavelengths. 
     In the embodiment shown in  FIG. 5 , a plurality of IR lamps  425  are disposed in a parallel orientation relative to the longitudinal axis of the chamber  100  ( FIG. 1 ). In this embodiment, each IR lamp  425  is disposed substantially parallel to a gas injection path as defined by the directional orientation of the ports  320 . While not shown, one or more IR lamps  425  may include a filter element ( FIG. 4 ) adapted to modulate bandwidth by selective transmission of specific wavelengths from the IR lamp  425 . 
     In the embodiment shown in  FIG. 6 , a single IR lamp  425  is disposed in a radial direction to the chamber  100  ( FIG. 1 ). In this embodiment, the IR lamp  425  is disposed normal to a gas injection path as defined by the directional orientation of the ports  320 . Additionally, the gas injection block  210  may include a plate  610  positioned between the IR lamp  425  and plenums  224   N  (not shown in this view). In one embodiment, the plate  610  may be configured as a window made of a material that is transparent to IR light. In another embodiment, the plate  610  may be configured as a filter element adapted to modulate bandwidth by selective transmission of specific wavelengths from the IR lamp  425 . In yet another embodiment, the plate  610  may be adapted as a filter element having multiple zones  615 A,  615 B adapted block specific wavelengths in each zone. 
     EXAMPLES 
     In one example, a blanket SiGe film was formed on a 300 mm wafer in the chamber  100  using the gas distribution assembly  150  as shown in  FIG. 2 . The chamber was provided with a pressure of about 10 Torr and a surface temperature in the processing region  118  of about 750° C. with a power density of about 45 W/cm 2 . Dichlorosilane and germane was introduced to the processing region  118  from the gas distribution assembly  150  at about 0.5% and 0.01%, respectively. Non-thermal energy from the IR lamps  225 A- 225 F operating at a power of about 30 watts produced a temperature measured at the sheath  315  of about 138° C. This produced a noticeable decrease in film growth rate and an increase in the percentage of germanium in the film. 
     In another example, a selective SiGe film was formed on a 300 mm wafer in the chamber  100  using the gas distribution assembly  150  as shown in  FIG. 2 . The chamber was provided with a pressure of about 10 Torr and a surface temperature in the processing region  118  of about 750° C. with a power density of about 45 W/cm 2 . Dichlorosilane and germane was introduced to the processing region  118  from the gas distribution assembly  150  at about 0.5% and 0.01%, respectively. Hydrogen chloride was also provided at about 0.5%. Non-thermal energy from the IR lamps  225 A- 225 F operating at a power of about 30 watts produced a temperature measured at the sheath  315  of about 138° C. This produced a significant decrease in film growth rate and an improved film profile. 
     In another example, a selective SiGe film was formed on a 300 mm wafer in the chamber  100  using the gas distribution assembly  150  as shown in  FIG. 2 . The chamber was provided with a pressure of about 10 Torr and a surface temperature in the processing region  118  of about 750° C. with a power density of about 45 W/cm 2 . Silane and hydrogen chloride was introduced to the processing region  118  from the gas distribution assembly  150  at about 0.25% and 1.125%, respectively. Non-thermal energy from the IR lamps  225 A- 225 F operating at a power of about 25 watts produced a temperature measured at the sheath  315  of about 110° C. This produced a noticeable increase in percentage of germanium in the film and a decrease in film growth rate. 
     In another example, a selective SiGe film was formed on a 300 mm wafer in the chamber  100  using the gas distribution assembly  150  as shown in  FIG. 2 . The chamber was provided with a pressure of about 10 Torr and a surface temperature in the processing region  118  of about 750° C. with a power density of about 45 W/cm 2 . Silane and germane was introduced to the processing region  118  from the gas distribution assembly  150  at 0.25% and 1.225%, respectively. Hydrogen chloride was also provided at about 0.575%. Non-thermal energy from the IR lamps  225 A- 225 F operating at a power of about 25 watts produced a temperature measured at the sheath  315  of about 110° C. This produced a significant decrease in film growth rate (about 56.5 Å/minute) and an increase in the percentage of germanium in the film (about 0.25%). 
     While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.