KR20150126776A - Method of enhancing dopant incorporation in epitaxial film using halogen molecules as reactant in deposition - Google Patents

Abstract

Embodiments of the present invention generally relates to a method of forming silicone epitaxial layers on semiconductor devices. The methods comprises: a step of heating a substrate arranged in a treating volume of a treatment chamber; and a step of performing a depositing process to form a silicone epitaxial layer on the substrate by exposing the substrate to a catalytic gas containing halogen molecules, and one or more deposition gas including a silicone source and a dopant source. In the embodiment, the catalytic gas includes a chlorine gas.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a method for enhancing dopant incorporation in an epitaxial film using halogen molecules as a reactant during deposition,

Embodiments of the present disclosure generally relate to the field of semiconductor manufacturing processes and devices, and more particularly, to a method of depositing a silicon-containing film to form a semiconductor device.

Size reduction of metal oxide-semiconductor field-effect transistors (MOSFETs) enables continuous improvement in cost per unit function, density and speed performance of integrated circuits. come. In addition, the semiconductor industry is in the age of transitioning from 2D transistors, which are usually planar, to 3D transistors using 3D gate structures. In 3D gate structures, the channel, source and drain are raised from the substrate, and then the gate surrounds the channel in three planes. The goal is to limit the current only to the elevated channel, and to invalidate any path through which electrons can leak. One such type of 3D transistor is known as a FinFET (Fin field-effect transistor), where the channel connecting the source and drain is a thin "fin" As a result, the current is limited to the channel, thereby preventing leakage of electrons.

In the industry, selective epitaxial deposition processes have been used to form the necessary source / drain extensions, raised source / drain or epi layers of silicon-containing materials in 3D transistors. Generally, the selective epitaxial process involves a deposition reaction and an etching reaction. To achieve process selectivity by etching an amorphous film on a defective dielectric epitaxial film in a selective epitaxial process or to remove deposited gasses or deposited residues remaining from chamber components in a chamber cleaning process, Chlorine gas can be used as an etching chemical. Chlorine gas is highly active and can readily react with the deposition process gases (typically including hydrogen and hydrides) at low temperatures, so that to avoid affecting the film growth rate, chlorine gas and deposition process gases Are not commonly used together during the deposition step. The deposition efficiency or film growth rate of the deposition process gases can be adjusted by alternately performing deposition and etching reactions or introducing the etch chemistry and deposition process gases separately into the reaction chamber using controlled time and process conditions , But such approaches are complex and time consuming and ultimately affect throughput and overall productivity.

It would therefore be desirable to provide simultaneous processes capable of reacting the etch chemistries with the deposited process gases during the deposition reaction, while providing the required film growth rates and film properties.

Embodiments of the disclosure generally relate to a method for forming silicon epitaxial layers on semiconductor devices. In one embodiment, the method includes heating a substrate disposed within a processing volume of the processing chamber; And forming a silicon epitaxial layer on the substrate by exposing the substrate to a catalyst gas, a silicon source and a dopant source containing halogen molecules of formula XY, wherein X and Y are halogen atoms. In one example, X is chlorine.

In another embodiment, the method includes heating a substrate disposed within a processing volume of the processing chamber; And forming a silicon epitaxial layer on the substrate by flowing a catalytic gas containing halogen molecules of the formula XY to the process chamber simultaneously or concurrently with the silicon source and phosphorus source, Atoms. In one example, X is chlorine.

In another embodiment, a method of forming a film on a substrate in a processing chamber is provided. The method comprises forming an epitaxial layer on a substrate by flowing a catalytic gas containing halogen molecules of the formula XY and at least one deposition gas comprising a deposition gas source and a dopant source into the process chamber, Lt; / RTI > are halogen atoms. The film-forming gas source may include one or more Group III precursor gases, a Group V precursor gas, a Group IV precursor gas, or a Group VI precursor gas. In one example, X is chlorine.

In order that the features of the disclosure described above may be understood in detail, a more particular description of the disclosure, briefly summarized above, may be referred to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the present disclosure is capable of other embodiments of equivalent effect, and therefore, the appended drawings illustrate only typical embodiments of the disclosure and are not therefore to be considered to be limiting of its scope .
FIG. 1A is a schematic side cross-sectional view of an exemplary process chamber that may be utilized to practice various embodiments of the disclosure.
FIG. 1B is a schematic side cross-sectional view of the chamber of FIG. 1A rotated 90 degrees.
FIG. 2 is an isometric view of one embodiment of a gas process kit comprising one or more liners as shown in FIGS. 1A and 1B. FIG.
3 is an isometric view of the gas distribution assembly shown in FIG.
FIG. 4 is a partial isometric view of one embodiment of a process kit that may be utilized in the process chamber of FIG. 1A.
FIG. 5 is a partial isometric view of another embodiment of a process kit that may be utilized in the process chamber of FIG. 1A.
6 is a flow diagram illustrating an exemplary epitaxial process utilized to form a layer on a substrate in accordance with embodiments of the present disclosure.
7A is a graph illustrating the tensile stress of an epitaxial layer formed according to certain embodiments of the disclosure.
7B is an enlarged graph "E" of FIG. 7A showing the details of the XRD profile for the epitaxial layer.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that the components disclosed in one embodiment may be advantageously utilized in other embodiments without specific reference.

Embodiments of the disclosure generally relate to methods for forming silicon epitaxial layers on semiconductor devices. These methods include forming a silicon epitaxial layer on a substrate using chlorine gas as a reactant or catalyst during an epitaxial deposition process. The deposited silicon epitaxial layer has a concentration of about 1 x 10 &^lt; ²¹ > atoms or more per cubic centimeter. Concentrations of phosphorus greater than about 1 x 10 &^lt; ²¹ > atoms per cubic centimeter cause significant tensile strain in the deposited layer, thereby improving channel mobility. The resistivity of the epitaxially grown layer is significantly lower compared to epitaxial processes that do not use chlorine gas in the deposition stage.

Illustrative chamber  hardware

IA is a schematic side cross-sectional view of an exemplary process chamber 100 that may be utilized to implement various embodiments of the deposition process discussed in this disclosure. The chamber 100 may be used to perform chemical vapor deposition, such as epitaxial deposition processes, but the chamber 100 may also be used for etching or other processes. Non-limiting examples of suitable process chambers may include an RP EPI reactor, an Elvis chamber, and a Lennon chamber, both of which are commercially available from Applied Materials, Inc. of Santa Clara, California. In the following, although the process chamber 100 is described as being utilized to implement the various embodiments described herein, other semiconductor process chambers from different manufacturers may also be utilized to implement the embodiments described in this disclosure . The process chamber 100 may be added to the available CENTURA ^® integrated processing system from Applied Materials, Inc. of Santa Clara, California.

The chamber 100 includes a housing structure 102 made of a process resistant material such as aluminum or stainless steel. The housing structure 102 surrounds various functional elements of a process chamber 100 such as a quartz chamber 104 that includes an upper chamber 106 and a lower chamber 108 and a processing volume 110 It is included in it. A substrate support 112 made of a graphite material or a ceramic material coated with a silicon material such as silicon carbide is adapted to receive the substrate 114 in the quartz chamber 104. Reactive species from the precursor reactive material materials may be applied to the processing surface 116 of the substrate 114 and subsequently the byproducts may be removed from the processing surface 116. Heating of the substrate 114 and / or the processing volume 110 may be provided by radiation sources such as the upper lamp modules 118A and the lower lamp modules 118B. In one embodiment, the upper lamp modules 118A and lower lamp modules 118B are infrared lamps. Radiation from the lamp modules 118A and 118B proceeds through the upper quartz window 120 of the upper chamber 106 and through the lower quartz window 122 of the lower chamber 108. If necessary, cooling gases for the upper chamber 106 enter through the inlet 124 and exit through the outlet 126.

The reactive species are provided to the quartz chamber 104 by a gas distribution assembly 128 and processing byproducts are removed from the processing volume 110 by an exhaust assembly 130 that typically communicates with a vacuum source (not shown) . The diluent, purge and vent gases for the chamber 100 as well as the precursor reactant materials enter through the gas distribution assembly 128 and exit through the exhaust assembly 130. The chamber 100 also includes a plurality of liners 132A-132H (only the liners 132A-132G are shown in FIG. 1A). The liner 132A-132H shields the process volume 110 from the metal walls 134 surrounding the process volume 110. [ In one embodiment, the liner 132A-132H constitutes a process kit that covers all metal components that may be exposed to this process volume in communication with or otherwise in communication with the process volume 110.

A lower liner 132A is disposed in the lower chamber 108. [ The upper liner 132B is at least partially disposed in the lower chamber 108 and adjacent the lower liner 132A. An exhaust insert liner assembly 132C is disposed adjacent the top liner 132B. In FIG. 1A, an exhaust insert liner 132D is disposed adjacent the exhaust insert liner assembly 132C and may replace a portion of the top liner 132B to facilitate installation. An injector liner 132E is shown on the side facing the exhaust insert liner assembly 132C and the exhaust insert liner 132D in the process volume 110. [ The injector liner 132E is configured as a manifold for providing at least one fluid, such as a gas or a plasma of a gas, One or more fluids are provided to the injector liner 132E by the injection insert liner assembly 132F. The baffle liner 132G is connected to the injection insert liner assembly 132F. The baffle liner 132G is connected to the first gas source 135A and the optional second gas source 135B and is connected to the injection insert liner assembly 132F and to the openings 136A and 136B formed in the injector liner 132E. Lt; / RTI >

One or more gases may flow from the first gas source 135A and the second gas source 135B through the baffle liner 132G, the injection insert liner assembly 132F and the one or more openings 136A formed in the injector liner 132E And 136B. ≪ / RTI > One or more openings 136A and 136B formed in the injector liner 132E are connected to outlets configured for a laminar flow path 133A or a jetted flow path 133B. The openings 136A and 136B may be configured to provide separate or multiple gas flows having various parameters such as velocity, density, or composition. In one embodiment in which the plurality of openings 136A and 136B are adapted, the openings 136A and 136B are part of the gas distribution assembly 128 to provide a sufficiently large gas flow to substantially cover the diameter of the substrate (E.g., injector liner 132E). ≪ / RTI > For example, each of the openings 136A and 136B may be arranged as far as possible within at least one linear group to provide a gas flow that generally corresponds to the diameter of the substrate. Alternatively, the openings 136A and 136B may be arranged in substantially the same plane or level to flow the gas (s) in a planar laminar flow manner, as discussed below with respect to Fig.

Each of the flow paths 133A, 133B is configured to flow to the exhaust insert liner 132D across axis A 'in a generally planar laminar flow manner. The axis A is substantially perpendicular to the longitudinal axis A "of the chamber 100. The flow paths 133A and 133B flow into a plenum 137 formed in the exhaust insert liner 132D, The plenum 137 is connected to an exhaust or vacuum pump (not shown) in a direction substantially parallel to the longitudinal axis A " To the manifold 139 which directs the exhaust flow path 133C to the exhaust manifold. At least an injection insert liner assembly 132F is disposed through the injection cap 129 and may be partially supported by the injection cap.

1B is a schematic side cross-sectional view of the chamber 100 of FIG. ≪ RTI ID = 0.0 > 1A < / RTI > For the sake of brevity, not all components similar to the chamber 100 described in FIG. 1A will be described. In FIG. 1B, slit valve liner 132H is shown disposed through metal walls 134 of chamber 100. 1B, a top liner 132B is shown adjacent the lower liner 132A instead of the injector liner 132E shown in FIG. 1A. 1B, the upper liner 132B may be replaced by a lower liner 132A (not shown) on the side opposite the slit valve liner 132H in the chamber 100, instead of the exhaust insert liner 132D shown in Fig. ). ≪ / RTI > In the rotated view shown in FIG. 1B, the upper liner 132B covers the metal walls 134 of the upper chamber 106. The top liner 132B also includes an inwardly extending shoulder 138. The shoulder < RTI ID = 0.0 > 138 < / RTI > The inwardly extending shoulder 138 forms a lip that supports an annular preheating ring 140 that locks the precursor gases into the upper chamber 106.

FIG. 2 is an isometric view of one embodiment of a gas process kit 200 including one or more liners 132A-132H as shown in FIGS. 1A and 1B. The liners 132A-132H are modular and are intended to be replaced singly or collectively. For example, one or more of the liners 132A-132H may be replaced with other liners adapted for different processes, without replacing the other liners 132A-132H. Therefore, the liner 132A-132H facilitates configuring the chamber 100 for different processes without replacing all of the liner 132A-132H. The process kit 200 includes a lower liner 132A and an upper liner 132B. Both the lower liner 132A and the upper liner 132B include a generally cylindrical outer diameter 201 that is sized to be received in the chamber 100 of Figures 1A and 1B. Each of the liner 132A-132H may be configured to be coupled to the chamber 132 by interlocking devices such as gravity, and / or mating recesses formed in or on a portion of the liner 132A-132H, As shown in FIG. The inner surfaces 203 of the lower liner 132A and the upper liner 132B form a portion of the processing volume 110. The top liner 132B includes cutout portions 202A and 202B sized to receive an exhaust insert liner 132D and an injector liner 132E as shown in the cross section in Figure 1A. Each of the cutout portions 202A, 202B define recessed regions 204 of the upper liner 132B adjacent the inwardly extending shoulder 138.

In one embodiment, each of the injection insert liner assembly 132F and the exhaust insert liner assembly 132C includes two sections. The injection insert liner assembly 132F includes a first section 206A and a second section 206B connected at one side by a baffle liner 132G. Similarly, the exhaust insert liner assembly 132C includes a first section 208A and a second section 208B. Each of the sections 206A and 206B of the injection insert liner assembly 132F receives gases from the first gas source 135A and the second gas source 135B through the baffle liner 132G. The gases flow through the injection insert liner assembly 132F and are routed to the plurality of first outlets 210A and the plurality of second outlets 210B in the injector liner 132E. In one aspect, the injection insert liner assembly 132F and the injector liner 132E constitute a gas distribution manifold liner. Thus, the gases from the first gas source 135A and the second gas source 135B are separately introduced into the processing volume 110. [ Each of the gases can be dissociated before or after exiting the outlets 210A and 210B and flowing across the process volume 110 for deposition onto a substrate (not shown). The dissociated precursors remaining after deposition are introduced into the exhaust insert liner assembly 132C and exhausted.

The liner 132A-132H is formed by removing the upper quartz window 120 from the metal walls 134 of the chamber 100 to access the upper chamber 106 and the lower chamber 108, ). ≪ / RTI > In one embodiment, at least a portion of the metal walls 134 may be removable to facilitate replacement of the liners 132A-132H. The baffle liner 132G is connected to the injection cap 129 which can be fixed to the outside of the chamber 100. The lower liner 132A, which includes an inner diameter larger than the horizontal dimension of the substrate support 112, is installed in the lower chamber 108. The lower liner 132A may rest on the lower quartz window 122. After the lower liner 132A is positioned on the lower quartz window 122, the exhaust insert liner assembly 132C, the injection insert liner assembly 132F, and the slit valve liner 132H may be installed. The injection insert liner assembly 132F may be connected to the baffle liner 132G to facilitate gas flow from the first gas source 135A and the second gas source 135B. After installation of the exhaust insert liner assembly 132C, injection insert liner assembly 132F and slit valve liner 132H, the top liner 132B may be installed. The annular preheating ring 140 may be located on a shoulder 138 that extends into the interior of the top liner 132B. In order to facilitate gas flow from the injection insert liner assembly 132F to the injector liner 132E an injector liner 132E is provided in the aperture formed in the top liner 132B and connected to the injection insert liner assembly 132F . The exhaust insert liner 132D may be installed above the exhaust insert liner assembly 132C in the aperture formed in the top liner 132B against the injector liner 132E. In some embodiments, the injector liner 132E may be replaced with another injector liner configured for a different gas flow scheme. Similarly, the exhaust insert liner assembly 132C can be replaced with another exhaust insert liner assembly configured for different exhaust flow schemes.

An exemplary gas distribution assembly

3 is a cross-sectional view of the gas distribution of FIG. ≪ RTI ID = 0.0 > 1A < / RTI > showing the embodiments of the injector liner 132E, injection insert liner assembly 132F and baffle liner 132G (collectively referred to as gas distribution manifold liner 300) Is an isometric view of assembly 128. The gas distribution assembly 128 shown in FIG. 3 and the various process kits 200 shown in FIGS. 4 and 5 can be used to implement various embodiments of the deposition process discussed in this disclosure. In one embodiment, shown in Figure 3, an injector liner 132E is connected to the injection insert liner assembly 132F and is configured to dispense the gases. The gas distribution manifold liner 300 may be configured to be interchangeable with other gas distribution manifold liners.

Process gases from the first gas source 135 A and the second gas source 135 B flow through the injection cap 129. The injection cap 129 includes a plurality of gas passages connected to ports (not shown) formed in the baffle liner 132G. In one embodiment, the lamp modules 305 may be disposed in the injection cap 129 to preheat the precursor gases within the injection cap 129. Baffle liner 132G includes conduits (not shown) for flowing gases into injection insert liner assembly 132F. The injection insert liner assembly 132F includes ports (not shown) for routing gases to the first outlets 210A and second outlets 210B of the gas distribution manifold liner 300. [ In one embodiment, the gases from the first gas source 135A and the second gas source 135B are separated until they exit the first outlets 210A and the second outlets 210B It remains. In one aspect, gases are preheated in one or more of baffle liner 132G, injection insert liner assembly 132F, and gas distribution manifold liner 300 and injection cap 129. In one embodiment, The preheating of the gases may be accomplished by one or a combination of the top lamp modules 118A, the bottom lamp modules 118B (both shown in FIG. 1A), and the lamp modules 305 on the injection cap 129 Lt; / RTI > In one aspect, gases are heated by energy from lamp modules 305, upper lamp modules 118A, and / or lower lamp modules 118B on injection cap 129, Lt; RTI ID = 0.0 > 210A < / RTI > and second outlets 210B.

Depending on the dissociation temperature of the process gases used in the first gas source 135A and the second gas source 135B, only one of the gases may be ionized upon exiting the gas distribution manifold liner 300, The gas is heated but remains gaseous when exiting the gas distribution manifold liner 300. A detailed description and various examples of injection caps having a plurality of gas passages are described in U.S. Patent Application Publication No. 2008/0210163, published on Sep. 4, 2008, which is incorporated herein by reference in its entirety.

FIG. 4 is a partial isometric view of one embodiment of a process kit 200 that may be utilized in the chamber 100 of FIG. 1A. The process kit 200 may include one embodiment of an injector liner 132E that is shown as a gas distribution manifold liner 400 and may be connected to an injection insert liner assembly 132F. The baffle liner 132G is shown between the sections 206A and 206B of the injection insert liner assembly 132F and the injection cap 129. [ The gas distribution manifold liner 400 may include a dual zone inject capability wherein each zone provides different flow characteristics, such as speed. The dual zone injection includes a first injection zone 410A and a second injection zone 410B disposed in different planes that are vertically spaced. In one embodiment, each of the injection zones 410A and 410B is spaced to form an upper zone and a lower zone. Alternatively, the first outlets 210A and the second outlets may be disposed in substantially the same plane or level as shown in Fig. The process kit 200 shown in Figure 5 is similar to the process kit 200 shown in Figure 4 except for the other embodiment of the injector liner 132E shown as gas distribution manifold liner 500. [ Do.

Referring again to FIG. 4, the first injection zone 410A includes a plurality of first outlets 210A, and the second injection zone 410B includes a plurality of second outlets 210B. Each of the first outlets 210A is disposed on a first surface 420A of the gas distribution manifold liner 400 while each of the second outlets 210B is disposed on a first surface 420A of the gas distribution manifold liner 400. In one embodiment, Is disposed on the second surface 420B of the gas distribution manifold liner 400 which is recessed from the gas distribution manifold liner 400. [ For example, the first surface 420A may be formed at a radius less than the radius used to form the second surface 420B.

In one embodiment, the injection zones 410A and 410B are adapted to provide different fluid flow paths, wherein fluid metrics such as fluid velocity may be different. For example, the first outlets 210A of the first infusion section 410A may provide fluid at a higher rate to form the stream path 133B, 2 outlets 210B may provide a laminar flow path 133A. The laminar flow paths 133A and 133B are configured to provide the gas pressure, the size of the outlets 210A and 210B, the outlets 210A and 210B and the chambers 505A and 505B (Figs. 5A and 5B) (E.g., cross-sectional dimensions and / or lengths) disposed between the outlets 210A and 210B and the chambers 505A and 505B disposed between the outlets 210A and 210B and the chambers 505A and 505B May be provided by one or a combination of angles and / or numbers of bends. In addition, the velocity of the fluids can be provided by adiabatic expansion of the precursor gases as fluids enter the processing volume 110.

In one aspect, the dual zone injection provided by the first injection zone 410A and the second injection zone 410B facilitates various levels of injection for different gases. In one embodiment, to provide a precursor to the processing volume 110 (shown in FIG. 1A) at different vertical distances over the processing surface 116 of substrate 114 (both shown in FIG. 1A) The first injection zone 410A and the second injection zone 410B are spaced apart in different planes. This vertical separation can provide enhanced deposition parameters, by taking into account the adiabatic expansion of certain gases that may be utilized. In some embodiments (not shown), the first outlets 210A of the first infusion section 410A are oriented such that at least one of the first outlets 210A is at an angle to the processing surface of the substrate . This angle can be from about 0 degrees to about 145 degrees and can be selected to provide a desired amount of cross-flow interaction between the first process gas and the second process gas. A detailed description of various examples of tilted gas outlets is set forth in U.S. Patent Application Publication No. 2011/0174212, published July 21, 2011, which is incorporated herein by reference in its entirety.

Exemplary methods using chlorine gas as a catalyst for deposition Epitaxial  process

FIG. 6 is a flow chart illustrating an exemplary epitaxial process 600 utilized to form a silicon-containing layer on a substrate in accordance with embodiments of the present disclosure. It should be noted that the concept described in Figure 6 also applies to methods of forming other materials, such as those that do not contain silicon-containing elements in the deposited film. For example, embodiments of the present disclosure may be applicable to pure Ge, GeSn, GeP, GeB or GeSnB. Throughout this application, the term "silicon-containing" material, compound, film or layer should be interpreted to include a composition that includes at least silicon and includes germanium, carbon, boron, arsenic, gallium, and / . Other elements such as metals, halogens or hydrogen can also be incorporated into silicon-containing materials, compounds, membranes or layers, typically in parts per million (ppm) concentrations. Process 600 is described below with respect to the embodiments of process chamber 100 described above with respect to FIGS. 1A-5.

Process 600 begins at box 602 by loading a patterned substrate, such as substrate 114, into a process chamber, such as process chamber 100. The patterned substrates are substrates that contain electronic features formed within the processing surface 116 of the substrate 114 or on the processing surface 116. The patterned substrate may comprise monocrystalline surfaces, and / or a second surface that is non-monocrystalline, such as a polycrystalline or amorphous surface. Monocrystalline surfaces include a deposited single crystal layer or a crystalline bare crystalline substrate typically made of a material such as silicon, germanium, silicon germanium or silicon carbon. The polycrystalline or amorphous surfaces may include amorphous silicon surfaces as well as dielectric materials such as oxides or nitrides, especially silicon oxide or silicon nitride. It is understood that the substrate may comprise a plurality of layers or may include partially fabricated devices such as, for example, transistors, flash memory devices, and the like.

In box 604, the substrate is heated to a predetermined temperature. The process chamber may be maintained at a temperature ranging from about 250 ° C to about 1,000 ° C, which may be tailored to the particular process being performed. Suitable temperatures for performing the epitaxial process 600 may depend on the specific precursors used to deposit and / or etch the silicon-containing materials. In various embodiments, the temperature for preheating the process chamber is below about 750 占 폚, for example below about 550 占 폚. In one example, the substrate is heated to a temperature of from about 550 [deg.] C to about 750 [deg.] C. In another example, the substrate is heated to a temperature between about 300 [deg.] C and about 550 [deg.] C. In another example, the substrate is heated to a temperature of about 300 캜 to about 750 캜. Increased temperatures can generally lead to increased throughput, but they can be achieved by minimizing the thermal budget of the final device by heating the substrate to a minimum temperature sufficient to thermally decompose the process reagents and deposit a layer on the substrate . The process chamber may be maintained at a pressure of from about 0.1 Torr to about 760 Torr, for example, from about 1 Torr to about 100 Torr, for example, from about 40 Torr to about 50 Torr. Depending on the process mode or when no low pressure deposition chambers are used, it is believed that pressures greater than about 100 Torr, for example from about 300 Torr to about 760 Torr, are expected.

At box 606, a deposition process is performed by exposing the patterned substrate to a deposition gas to form an epitaxial layer on the surface of the substrate. The deposition gas may include one or more deposition gases, and optionally one or more of a dopant precursor gas, an etchant gas, or a carrier gas. The deposition gas is supplied from the gas source 135A and / or the gas source 135B, through the baffle liner 132G, the injection insert liner assembly 132F, and into the injector liner 132E, (Or through the first outlets 210A and / or the second outlets 210B as shown in Figures 2-5) to the processing volume 110 via one or more openings 136A and / or 136B . The deposition gas is directed toward the plenum 137 formed in the exhaust insert liner 132D in the flow path 133A or 133B that is substantially parallel to or inclined to the processing surface 116, 0.0 > 116 < / RTI >

In those instances where a silicon-containing material is desired, the deposition gas may comprise at least a silicon source and a carrier gas, and may optionally include at least one second element source, such as a germanium source and / or a carbon source. In cases where a germanium-containing material is desired, the deposition gas may comprise at least a germanium source and a carrier gas (no silicon source present). If desired, the deposition gas may comprise one or more precursor gases selected from Group III precursor gases, Group V precursor gases, Group VI precursor gases, or Group IV precursor gases. In various instances, the deposition gas may further comprise a dopant compound to provide a source of a dopant, such as phosphorus, boron, arsenic, gallium, and / or aluminum. In one embodiment, at least one catalytic gas is also introduced into the process chamber and is thermally driven to catalyze the deposition gas during deposition. As discussed below, such catalysis has been observed to advantageously increase the tensile strain and lower the resistivity of the epitaxially grown layer.

The silicon source may be provided to the process chamber during box 606 at a rate ranging from about 5 sccm to about 500 sccm. In some embodiments, the silicon source is provided to the process chamber at a rate from about 10 sccm to about 300 sccm, such as from about 50 sccm to about 200 sccm, for example, about 100 sccm. Silicon sources useful in the deposition gas for depositing silicon-containing compounds include silanes, halogenated silanes and organosilanes. Silanes include silanes (SiH ₄ ), and higher silanes having the empirical formula Si _x H _{(2x + 2)} such as disilane (Si ₂ H ₆ ), trisilane (Si ₃ H ₈ ), and tetrasilane ₄ H ₁₀ ), or other higher order silanes such as polychlorosilanes. The halogenated silane can be a compound having the empirical formula X ' _y Si _x H _{(2x + 2-y)} where X' = F, Cl, Br or I such as hexachlorodisilane (Si ₂ Cl ₆ ) Chlorosilane (SiCl ₄ ), dichlorosilane (Cl ₂ SiH ₂ ), and trichlorosilane (Cl ₃ SiH). The organosilane is a compound having the empirical formula R _y Si _x H _{(2x + 2-y)} where R = methyl, ethyl, propyl or butyl such as methylsilane ((CH ₃ ) SiH ₃ ), dimethylsilane ( CH _{3) 2} SiH _2), ethylsilane _{((CH 3 CH 2) SiH} 3), disilane _{((CH 3) Si 2 H} 5), dimethyl silane _{((CH 3) 2 Si 2} H 4) and Hexamethyl disilane ((CH ₃ ) ₆ Si ₂ ).

The silicon source may be provided with a carrier gas into the process chamber. The carrier gas may have a flow rate of about 1 SLM (standard liters per minute) to about 100 SLM, such as about 3 SLM to about 30 SLM. Suitable carrier gases may be inert carrier gases, such as nitrogen (N ₂ ), hydrogen (H ₂ ), argon, helium, or combinations thereof. The carrier gas may be selected based on the process temperature during the epitaxial process and / or the precursor (s) used. Nitrogen can be used as a carrier gas in embodiments featuring low temperature (e. G., <800 ° C) processes. Low temperature processes may be accessible in part due to the use of chlorine gas in the deposition process, which is discussed further below. Nitrogen remains inert during the low temperature deposition processes. Therefore, nitrogen is not incorporated into the deposited silicon-containing material during low temperature processes.

The deposition gas may further comprise at least one dopant compound to provide a source of an elemental dopant such as phosphorus, boron, arsenic, gallium or aluminum. The dopants provide deposited silicon-containing compounds with various conductive characteristics, such as directional electron flow in the controlled and required pathways required by the electronic device. The films of silicon containing compounds are doped with certain dopants to achieve the desired conductivity characteristics.

The dopant source may be provided to the process chamber during box 606 at a rate in a range from about 0.1 sccm to about 600 sccm, such as from about 0.5 sccm to about 150 sccm, such as from about 3 sccm to about 100 sccm. Phosphorus containing dopants useful as dopant sources may include phosphine (PH ₃ ). Boron-containing dopants useful as dopant sources include borane and organoborane. Boran contains compounds with the empirical formula R _x BH _(3-x) , while R = methyl, methylene, and the like, while borane comprises borane, diborane (B ₂ H ₆ ), triborane, tetraborane and pentaborane, Ethyl, propyl or butyl, and x = 1, 2 or 3. Alkyl borane trimethyl borane _{((CH 3) 3 B)} , dimethyl borane _{((CH 3) 2 BH)} , triethylborane _{((CH 3 CH 2) 3} B) and diethyl borane ((CH ₃ CH _{2) 2} BH). In addition, the dopant are arsine (arsine) (AsH _3), and alkyl phosphines, such as the empirical formula may include those having the _{R x PH (3-x)} , where R = methyl, ethyl, propyl or butyl, x = 1, 2, or 3; Alkylphosphines include trimethylphosphine ((CH ₃ ) ₃ P), dimethylphosphine ((CH ₃ ) ₂ PH), triethylphosphine ((CH ₃ CH ₂ ) ₃ P) and diethylphosphine ₃ CH ₂ ) ₂ PH). Al and gallium dopant sources may include alkylated and / or halogenated derivatives such as those described by empirical formula R _x MX _(3-x) , where M = Al or Ga and R = methyl, ethyl, Or butyl, X = Cl or F, and x = 0, 1, 2 or 3. Examples of aluminum and gallium dopant sources include trimethyl aluminum (Me ₃ Al), triethylaluminum (Et ₃ Al), dimethylaluminum chloride (Me ₂ AlCl), aluminum chloride (AlCl _3), trimethyl gallium (Me ₃ Ga), tree Ethyl gallium (Et ₃ Ga), dimethyl gallium chloride (Me ₂ GaCl) and gallium chloride (GaCl ₃ ).

In cases where a phosphorus containing silicon epitaxial layer is desired, the deposition gas may comprise a silicon source, a phosphorus source and a carrier gas. Suitable silicon sources, phosphorus sources and carrier gases are discussed above. In some cases, the deposition gas may further comprise a germanium source. Although other silicon and phosphorous sources are expected, it is generally desirable that oxygen addition to the processing atmosphere be minimized or avoided.

During box 606, at least one catalytic gas is also introduced into the process chamber 100 and is thermally driven to catalyze the deposition gas. The catalytic gas may be provided to the process chamber at a rate ranging from about 3 sccm to about 400 sccm, such as from about 30 sccm to about 300 sccm, such as from about 60 sccm to about 150 sccm. In most cases, the catalyst gas flows simultaneously or concurrently with the deposition gas during the deposition stage (i. E. Co-flow mode). In some cases, the deposition gas can be continuously introduced into the process chamber, and the catalyst gas is provided at a predetermined interval (s). Exemplary catalyst gases may be those containing halogen molecules. In one embodiment, the catalytic gas is chlorine gas (Cl ₂ ). Since chlorine gas is a highly reactive gas capable of easily reacting with hydrogen and hydrides such as silane, dichlorosilane, disilane, PH ₃ , B ₂ H ₆ and the like even at a low temperature (for example, <500 ° C.) . Since chlorine can be activated at temperatures as low as about 300 ° C, the total epitaxial process temperature can be reduced, for example, by 50 ° C to 100 ° C compared to epitaxial processes that do not use chlorine as a reactant or catalyst . In particular, it has been surprisingly found that the use of chlorine gas as a reactant or catalyst in an epitaxial deposition process can enhance phosphorus incorporation in the epitaxially grown silicon layer during deposition, even though the supply of phosphorus precursors is low Lt; / RTI &gt; As compared to the in situ doping silicon ( "SiP") epitaxial layer, Cl ₂ - - is not used a Cl ₂ gas while depositing SiP Epi process, the catalytic action is a tensile strain while reducing the resistivity of the epitaxially grown layer Which ultimately increases the electron mobility in the channel and reduces the source / drain contact resistance for the metal oxide semiconductor field effect transistor.

Table 1 below illustrates the use of Cl ₂ gas as a catalytic gas during the layer deposition process according to embodiments of the present disclosure (Examples 3-7) or without catalyst gas (i.e., without Cl ₂ gas as in Example 1-2) The film properties of the formed SiP epitaxial layer are shown. In all the examples shown in Table 1, disilane (abbreviated as DS) was provided at a flow rate of 100 sccm, and nitrogen gas serving as a carrier gas was provided at a flow rate of 3 SLM. The phosphine was provided at three different flow rates of 5.1 sccm, 15 sccm, and 50 sccm. In all examples, the process chamber was heated and maintained at about 500 캜, and the chamber pressure was about 40 Torr. The process conditions described herein and throughout this disclosure are based on a 300 mm diameter substrate.

As can be seen in Examples 1 and 3, when chlorine gas was provided during the deposition process, the tensile strain of the epitaxially grown layer was advantageously increased from 0.03% to 0.10%, and the film resistivity was from 0.838 mΩ-cm to 0.332 m? -cm. More importantly, the phosphorus concentration was significantly increased from about 1.6 x 10 ²⁰ atoms per cubic centimeter to about 7.6 x 10 ²⁰ atoms per cubic centimeter. Also, the layer thickness was increased from about 556 ANGSTROM to about 707 ANGSTROM for a period of 150 seconds. The fact that the deposited epitaxial layer is thicker and the concentration of phosphorus is higher is considered to be an etchant chemistry, so that chlorine gas, which is not conventionally used in the deposition process, can be added to the layer without unduly affecting the growth rate. Suggesting that it strengthens.

Without being bound by any particular theory, various active intermediate precursors (e.g., SiCl _x , PCl _x ) spontaneously generated during an exothermic reaction between Cl ₂ and hydrogen and / or hydride gases, dopant gases, Is believed to be able to account for these desirable properties, such as higher tensile strain, better layer thickness growth, lower resistivity and higher dopant concentration in the deposited epitaxial layer. Additionally, at a concentration of at least about 1 x 10 &^lt; ²¹ &gt; atoms per cubic centimeter, the deposited epitaxial layer is not a purely doped silicon layer, rather it is an alloy between silicon and silicon phosphide Pseudocubic Si ₃ P ₄ ). The silicon / silicon phosphide alloy is believed to contribute to the increased tensile stress of the deposited epitaxial layer. The likelihood of forming a silicon / silicon phosphide alloy increases with increasing phosphorus concentration because the probability of adjacent phosphorus atoms interacting is increased.

Returning to Table 1, as the flow of chlorine gas increases from 30 sccm to 60 sccm (Example 4), 90 sccm (Example 5), and 150 sccm (Example 6), the tensile strain in the deposited epitaxial layer increases from 0.10% to 0.16% 0.21% and 0.31%, respectively, and the resistivity of the deposited epitaxial layer was also reduced from 0.332m? -Cm to 0.321m? -Cm, 0.287m? -Cm and 0.234m? -Cm, respectively. In the meantime, the phosphorus concentration and the layer thickness were also increased in comparison with Example 1 in which chlorine gas was not used as a reactant or catalyst at the time of deposition. Example 5 shows that when the phosphine gas is only flowing at 5.1 sccm and the chlorine gas is delivered to the process chamber at a rate of 90 sccm, the deposited epitaxial layer is in a higher amount (10 times higher than example 1 50 sccm) of the phosphine gas flowed and the chlorine gas had no tensile strain, higher phosphorus concentration and lower resistivity equivalent to Example 2, which was not provided. Therefore, the high flow of the phosphine gas itself does not induce a high tensile strain such as that induced by PH ₃ + Cl ₂ in the deposited epitaxial layer. Example 5 clearly shows that even with low PH ₃ gas supply, a highly strained and highly doped SiP epitaxial layer with low resistivity with low resistivity can still be achieved.

Example 7 shows another embodiment where both phosphine gas and chlorine gas flow rates are increased compared to Example 1 (PH ₃ increased from 5.1 sccm to 15 sccm and Cl ₂ increased from 0 sccm to 150 sccm). As can be seen, the resulting phosphorous-doped silicon epitaxial layer had a significantly increased tensile strain from 0.03% to 0.70%. In addition, the resulting layer had a resistivity of about 0.3 mOhm-cm compared to 0.838 mOhm-cm for the layer of Example 1. The layer thickness also increased from 556 ANGSTROM to 621 ANGSTROM, indicating that the chlorine gas also did not affect the overall film growth rate, but rather enhanced the epitaxial layer with a higher tensile strain and lower resistivity.

It should be noted that while the higher flow rates of the source gas can improve the tensile strain and resistivity of the deposited epitaxial layer, the examples given in Table 1 are based on a chamber pressure of 40 Torr. High flow rates of the source gas provided during low pressure deposition can lead to "surface poisoning" of the substrate, which inhibits epitaxial formation. Typically, when processing at pressures exceeding 300 Torr, for example from about 300 Torr to about 760 Torr, surface poisoning is not experienced due to the silicon source flux overcoming the poisoning effect. Thus, it may be advantageous to increase the process pressure for epitaxial processes that utilize a high dopant flow rate.

Examples 8 and 9 demonstrate that the deposited epitaxial layer has higher tensile strains (0.36% and 0.39%) and lower resistivity (0.239 &lt; RTI ID = 0.0 &gt; m &lt; 2 &gt; -cm and 0.256 m-cm). Excess chlorine gas tends to consume some disilane and PH ₃ gases in the gas phase and thus has some adverse effect on the layer thickness, but the total layer thickness is at least the strongest etchant gas in the layer It is not significantly affected to the extent expected. The lower tensile strain with excess chlorine gas can be attributed to the weaker deposition of less phosphorus atoms into the film.

7A is a graph showing the tensile stresses of the layers formed according to Examples 1, 3, 4, 5, 6, 8 and 9 shown in Table 1 above, as determined by high resolution X-ray diffraction. 7B is an enlarged graph "E" of FIG. 7A showing the details of the XRD profile for the DS cavity flow SiP with Cl ₂ flowing at different flow rates. Peak A corresponds to the tensile stress of the monocrystalline silicon substrate while Peak B corresponds to the tensile stress of the silicon germanium layer (350 ANGSTROM) which shows that peaks DI are visible and meaningful for data analysis As a reference layer. The peaks C, D, E, F, G, H, and I represent the tensile strength of the phosphorus containing epitaxial layer formed using Cl ₂ provided at a flow rate of 0 sccm, 30 sccm, 60 sccm, 90 sccm, 150 sccm, 200 sccm and 300 sccm during the deposition stage Respectively. Generally, the peaks CI have a shift of from about 350 seconds to about 850 seconds each, due to the tensile strain generated from the high dopant concentration. In addition, well defined edges of the peaks DI show high quality high strain SiP epitaxial layers with homogeneous composition with the addition of chlorine.

In operation, the catalytic gas flows simultaneously or together with the deposition gas during the epitaxial layer growth process. The catalytic gas may be introduced into the injector liner 132E from the gas source 135A and / or gas source 135B through the baffle liner 132G, the injection insert liner assembly 132F, May be provided through one or more openings 136A and / or 136B (or through first outlets 210A and / or second outlets 210B as shown in Figures 2-5). In some embodiments, the catalyst gas and the deposition gas are separately introduced into the gas process kit 200 and into the processing volume 110 (i.e., the catalyst gas and the deposition gas are mixed after entering the process chamber). In some embodiments, the catalyst gas and the deposition gas are premixed and mixed as a gas mixture (i.e., the catalyst gas and the deposition gas are premixed before entering the process chamber) before entering the gas process kit 200. The catalytic gas may be introduced into the processing volume 110 through one or more of the first outlets 210A (Figs. 2-5), while the deposition gas may flow into the second outlets 210B (Figs. 2-5) May flow through more than one, or vice versa. In one example, the catalytic gas and the deposition gas are co-flowed into the process volume 110 in substantially the same plane, i.e., the catalyst gas flows through at least one of the first outlets 210A, And flows through at least one of the illustrated second outlets 210B. Therefore, the catalyst gas and the deposition gas are mixed after entering the process chamber.

The epitaxial process at box 606 may be repeated until a predetermined thickness and / or film profile is achieved.

At box 608, the deposition process is terminated and a post-deposition baking process is selectively performed on the deposited epitaxial layer. A post-deposition bake process may be performed in-situ within the process chamber 100, or in a different thermal process chamber. The post-deposition bake process may be performed at a temperature of about 550 [deg.] C to about 800 [deg.] C in a process chamber of about 300 Torr for about 60 seconds to about 180 seconds, for example about 120 seconds. These process conditions can be varied to obtain the desired film properties. During the post-deposition bake process, inert gases and / or carrier gases, such as nitrogen, hydrogen, or other suitable gases may be introduced into the process chamber. The inert / carrier gas may be provided at a flow rate of about 3 SLM. By evacuating some of the dopants (e.g., phosphorous) from the deposited epitaxial layer during the post-deposition bake process, the epitaxial layer after baking exhibits a slight increase in resistivity and a slight decrease in tensile strain .

At box 610, an annealing process may optionally be performed to recover the degraded film properties during the post-deposition bake process. Alternatively, the annealing process of box 610 may be omitted, so that desired film properties are recovered by the process of box 608. [ The annealing processes described herein may refer to processes performed at temperatures greater than about &lt; RTI ID = 0.0 &gt; 600 C. &lt; / RTI &gt; The annealing processes may be performed using laser annealing processes, spike annealing processes, rapid thermal annealing processes, and / or furnace anneal processes. In one embodiment of the disclosure, a laser annealing process such as a dynamic surface annealing (DSA) process is performed. Laser annealing processes can transfer a constant energy flux from an energy source to a small area on the surface of the substrate while the substrate can be translated or scanned (or vice versa) against the energy delivered to this small area. The energy source may deliver electromagnetic radiation energy to perform the annealing process at desired areas of the substrate. Typical sources of electromagnetic radiation include, but are not limited to, optical radiation sources, electron beam sources, ion beam sources and / or microwave energy sources, any of which may be monochronistic or polychrome May be polychronistic, and may have any desired coherency. In one embodiment, the energy source is an optical radiation source using one or more laser sources. The lasers can be any type of laser, such as gas lasers, excimer lasers, solid state lasers, fiber lasers, semiconductor lasers, etc., and they can be configurable to emit light at a single wavelength or at two or more wavelengths simultaneously.

The laser annealing process can occur on a given area of the substrate for a relatively short period of time, such as, for example, about 1 second or less. In various embodiments, the laser annealing process is performed on the order of milliseconds. Millisecond annealing allows precise control over the placement of phosphorous in the deposited epitaxial layer, while providing improved yield performance. The temperature for the laser annealing process must be carefully chosen to avoid any adverse effects on the resistivity and tensile strain of the deposited layer.

Advantages of the present invention include high quality silicon (or germanium) epitaxial films exhibiting high tensile strain and low resistivity. By using chlorine gas as the reactant or catalyst during the epitaxial deposition process, phosphorus can be significantly incorporated into the layer without unduly affecting the growth rate, even with a small supply of phosphorus precursors. The high phosphorus concentration induces stress in the deposited epitaxial layer, thereby increasing the tensile strain, which results in increased carrier mobility and improved device performance.

While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure can be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow .

100: chamber
102: Housing structure
104: quartz chamber
106: upper chamber
108: Lower chamber
110: Processing volume
112: substrate support
114: substrate
116: Treatment surface
118A: lamp modules
118B: lamp modules
120: upper quartz window
122: Lower quartz window
124: inlet
126: Outlet
128: gas distribution assembly
129: Injection cap
130: Exhaust assembly
132A:
132B: upper liner
132C: exhaust insert liner assembly
132D: Exhaust liner
132E: injector liner
132F: injection insert liner assembly
132G: Baffle Liner
132H: Slit valve liner
133A:
133B:
133C: exhaust flow path
134: metal walls
135A: Gas source
135B: Gas source
136A: openings
136B:
137: Plenum
138: Shoulder
139: Manifold
140: ring preheating ring
200: Process Kit
201: Cylindrical outer diameter
202A: Cutout portions
202B: Cutout portions
203: internal surfaces
204: recessed regions
206A: first section
206B: second section
208A: first section
208B: second section
210A: first outlet
210B: second outlet
300: Gas distribution manifold liner
305: lamp modules
350: Silicon germanium layer
400: Gas Distribution Manifold Liner
410A: injection zone
410B: injection zone
420A: first surface
420B: second surface
500: Gas distribution manifold liner
505A: chamber
505B: chamber
600: Process
602: box
604: Box
606: box
608: Box
610: Box

Claims (15)

A method of forming a film on a substrate,
Heating the substrate disposed within the processing volume of the processing chamber; And
Forming a silicon epitaxial layer on the substrate by exposing the substrate to a catalyst gas, a silicon source and a dopant source containing halogen molecules of formula XY, wherein X and Y are halogen atoms,
&Lt; / RTI &gt; 2. The method of claim 1, wherein X is chlorine. The method of claim 1, wherein the silicon source comprises silane, dichlorosilane, disilane, trisilane, tetrasilane, or polychlorosilane. 2. The process of claim 1, wherein the catalyst gas is provided to the process chamber at a flow rate between about 3 sccm and about 300 sccm for a 300 mm diameter substrate, the dopant source having a flow rate of about 3 sccm to about 100 sccm for a 300 mm diameter substrate To the processing chamber. The method of claim 1, wherein the dopant source comprises phosphorous, boron, arsenic, gallium, or aluminum. 5. The method of claim 4, wherein the processing chamber is maintained at a pressure of about 1 Torr to 760 Torr. 2. The method of claim 1, wherein the substrate is heated to a temperature between about 300 [deg.] C and about 750 [deg.] C. 2. The method of claim 1, wherein the catalyst gas, the silicon source, and the dopant source are intermittently co-flowed into the process volume in substantially the same plane. A method of forming a film on a substrate,
Heating the substrate disposed within the processing volume of the processing chamber; And
Forming a silicon epitaxial layer on the substrate by flowing a catalyst gas containing halogen molecules of the formula XY simultaneously or concurrently with the silicon source and the phosphorous source, Halogen atoms -
&Lt; / RTI &gt; 10. The process of claim 9, wherein the catalyst gas is provided to the process chamber at a flow rate of about 3 sccm to about 300 sccm for a 300 mm diameter substrate, the source being a flow rate of about 3 sccm to about 100 sccm for a 300 mm diameter substrate To the processing chamber. 1. A method of forming a film on a substrate in a processing chamber,
Forming an epitaxial layer on the substrate by flowing a catalytic gas containing halogen molecules of formula XY and one or more deposition gases comprising a deposition gas source and a dopant source into the process chamber, Halogen atoms -
&Lt; / RTI &gt; 12. The method of claim 11, wherein the film forming gas source comprises a Group III precursor gas, a Group V precursor gas, a Group IV precursor gas, or a Group VI precursor gas, wherein the dopant source is phosphorus, boron, arsenic, gallium Or aluminum. 12. The method of claim 11, wherein the catalyst gas is provided to the processing chamber at a flow rate between about 3 sccm and about 300 sccm for a 300 mm diameter substrate. 12. The method of claim 11, wherein the dopant source is provided to the process chamber at a flow rate between about 3 sccm and about 100 sccm for a 300 mm diameter substrate. 12. The method of claim 11, wherein the catalytic gas, the film forming gas source, and the dopant source are co-flowed simultaneously or intermittently with a process volume in which the substrate is disposed.

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