TWI518747B - Multilayer substrate structure and method and system of manufacturing the same - Google Patents

Description

Multilayer substrate structure and manufacturing method and system thereof [Priority application]

U.S. Provisional Application No. 61/662,918, filed on June 22, 2012, and U.S. Provisional Application No. 61/659,944, filed on Jun. 14, 2012, filed on Jun. US non-provisional application No. 13/794,372, filed on March 11, 2013, US non-provisional application No. 13/794,327, filed on March 11, 2013, and US non-provisional application filed on March 11, 2013 The priority of the application is hereby incorporated by reference in its entirety in its entirety in its entirety in its entirety in its entirety in

Illustrative embodiments of the present invention generally relate to semiconductor materials, methods and apparatus, and more particularly to a multilayer substrate structure for epitaxial growth of a III-V compound semiconductor and a method for fabricating the same A system of multilayer substrate structures.

Group III-V compound semiconductors such as gallium nitride (GaN), gallium arsenide (GaAs), indium nitride (InN), aluminum nitride (AlN), and gallium phosphide (GaP) are widely used in electronic devices (eg, In the manufacture of microwave frequency integrated circuits, light-emitting diodes, laser diodes, solar cells, high-power high-frequency electronic components, and optoelectronic devices. It is desirable to increase the size (e.g., diameter) of the substrate to increase throughput and reduce cost. Because large-sized III-V compound semiconductors are very expensive to grow, they generally contain metals and metals. A wide variety of foreign materials of oxides, metal nitrides, and semiconductors (for example, niobium carbide (SiC), sapphire, and niobium) are used as substrates for epitaxial growth of III-V compound semiconductors.

However, due to the lattice mismatch between the GaN layer and the underlying substrate (an external material) and the thermal expansion coefficient mismatch, the epitaxial growth of the III-V compound semiconductor (eg, GaN) on the substrate (eg, sapphire) is epitaxial. The crystal quality of the layers (such as grain boundaries, misalignment and other extended defects, and point defects) present challenges. After returning to room temperature for processing, or returning to room temperature for processing, the difference in thermal expansion coefficient between the GaN layer and the underlying substrate causes large bending on the wafer, and a serious mismatch in lattice constant causes high occurrence. Dislocation density, unnecessary strain, and defects that diffuse into the epitaxial GaN layer. To overcome these problems, a stress relaxation strategy is utilized, such as growing a buffer layer between the GaN layer and the sapphire substrate, or offsetting the compressive strain and the tensile strain by alternately providing various appropriate material layers. However, due to the addition of the buffer layer or the stress relief layer, and due to the same deposition technique as that used in the growth of the active device layer, the dislocation density is still high, and the manufacturing cost and complexity are significantly increased. .

When an external material containing a metal, a metal oxide, a metal nitride, and a semiconductor such as tantalum carbide (SiC), sapphire, and hafnium is used as a substrate for epitaxial growth of a semiconductor, molecular beam epitaxy can be utilized. Epitaxy; MBE) technology or metal organic chemical vapor deposition (MOCVD) technology, and in some cases, atomic layer deposition (ALD) or atomic layer epitaxy; ALE) A thin semiconductor film is deposited on the substrate. However, not all atoms, ions, or molecules have the opportunity to be regularly arranged, resulting in many atoms. Undesirable bond orientation is formed and the crystal quality is significantly reduced and has a negative impact on the electronic properties of the semiconductor material. The crystal quality is usually described by a crystal size, a grain size, a carrier lifetime, and a diffusion length.

While certain techniques, such as Zone melt recrystallization (ZMR), are intended to improve the quality of crystalline materials, such techniques may have the disadvantage that the temperature used to melt a portion of the deposited film may be higher than The highest temperature that the underlying substrate can withstand. In order to prevent the underlying substrate from being heated to the melting point of the deposited film, the heating time can be shortened. However, shortening the heating time means that the crystal structure can be grown in the vertical direction while being solidified, rather than growing in the vertical direction and the lateral direction at the same time. Therefore, epitaxial growth can be performed mainly in the vertical direction rather than in the lateral direction, thereby forming small grain regions along the substrate.

In accordance with an exemplary embodiment of the present invention, a multilayer substrate structure includes: a substrate; a thermal matching layer formed on the substrate; and a lattice matching layer over the thermal matching layer. The thermal matching layer comprises at least one of molybdenum, molybdenum-copper, mullite, sapphire, graphite, aluminum oxynitride, tantalum, niobium carbide, zinc oxide, and rare earth oxide. The lattice matching layer comprises a first chemical element and a second chemical element to form an alloy. The first chemical element has a similar crystal structure and chemical properties to the second chemical element. The thermal expansion coefficient of the thermal matching layer is approximately equal to the thermal expansion coefficient of one member of the III-V compound semiconductor.

In accordance with an exemplary embodiment of the present invention, a method of fabricating a multilayer substrate structure includes providing a substrate and growing a thermal matching layer on the substrate. The thermal matching layer comprises at least one of molybdenum, molybdenum-copper, mullite, sapphire, graphite, aluminum oxynitride, cerium, lanthanum carbide, zinc oxide, and rare earth oxide. The method also includes growing a lattice above the thermal matching layer Matching layer. The lattice matching layer comprises a first chemical element and a second chemical element to form an alloy. The first chemical element has a similar crystal structure and chemical properties to the second chemical element. The thermal expansion coefficient of the thermal matching layer is approximately equal to the thermal expansion coefficient of one member of the III-V compound semiconductor.

According to an exemplary embodiment of the present invention, a method of depositing a film on a substrate includes: guiding a source material from a material source to a surface of the substrate by a line of sight deposition method; and disposing the substrate and the source material A shielding plate between the blocks blocks a predetermined portion of the substrate to form a blocked substrate portion and an unblocked substrate portion, thereby preventing source material from being deposited onto the initial blocked portion of the substrate; Relatively moving between the shielding plate and the substrate, so that the blocked substrate portion is reduced and the unblocked substrate portion is enlarged, thereby forming a moving lateral growth boundary, thereby achieving lateral epitaxial growth on the substrate. .

In accordance with an exemplary embodiment of the present invention, a system for depositing a film on a substrate includes a lateral control shutter. The lateral control shutter is disposed between the substrate and a source material and is configured to block a portion of the substrate to prevent deposition of the source material onto the blocked portion of the substrate. The lateral control shutter and/or one of the substrates moves relative to the other to form a moving lateral growth boundary edge, thereby achieving lateral epitaxial deposition on the substrate and forming a large surface on the substrate One of the particle sizes is deposited on the film.

100‧‧‧Multilayer substrate structure

102‧‧‧Substrate

102a‧‧‧Hot matching layer

104‧‧‧ epitaxial layer

106‧‧‧ lattice matching layer

108‧‧‧Amorphous layer

500‧‧‧ system

502‧‧‧film

504‧‧‧Substrate

506‧‧‧Horizontal control baffle/transverse baffle

508‧‧‧Material source

510‧‧‧heat source

512‧‧‧Drop control shutter

602‧‧‧Directional angular distribution

604‧‧‧ cosine angle distribution

706‧‧‧Horizontal control shutter

712‧‧‧ left end

714‧‧‧Area

716‧‧‧Separate grain

720‧‧‧ surface relief structure

722‧‧‧ seed crystal

724‧‧‧Area

A‧‧‧ transverse direction

L1‧‧‧The distance between the material source and the substrate

L2‧‧‧ lateral control of the distance between the baffle and the surface of the substrate

The exemplary embodiments of the present invention have been generally described above, and the drawings are not necessarily drawn to scale, in which: FIGS. 1A-1D illustrate an exemplary multilayer substrate structure according to an exemplary embodiment. Example sectional view; 2A illustrates a schematic diagram of a hexagonal closest packed structure; FIG. 2B illustrates a schematic diagram of a unit lattice showing a lattice constant; FIG. 3 illustrates a periodic table; and FIG. 4 illustrates a phase transition according to an exemplary embodiment. Phase diagram of the relationship between temperature and atomic percentage of constituent elements; FIG. 5 illustrates an exemplary system for depositing a film on a substrate according to an exemplary embodiment; and FIGS. 6A to 6C illustrate gasification in a sputtering deposition process An exemplary angular distribution of materials; and Figures 7A-7D illustrate an exemplary method of growing large extended crystals on a substrate in accordance with an exemplary embodiment of the present invention.

Hereinafter, various embodiments will be described more fully with reference to the accompanying drawings. The present invention is to be construed as being in the full part of the description of the invention. The same reference numerals throughout the drawings denote the same elements.

FIG. 1A illustrates a cross-sectional view of one example of an exemplary multilayer substrate structure 100, in accordance with an exemplary embodiment. The multilayer substrate structure 100 can include a substrate 102 and an epitaxial layer 104 epitaxially grown on the substrate 102. Depending on the application, substrate 102 can comprise a semiconductor material, a compound semiconductor material, or other type of material (eg, a metal or a non-metal). For example, the material may comprise molybdenum, molybdenum-copper, mullite, sapphire, graphite, aluminum oxynitride, tantalum, tantalum carbide, zinc oxide, and rare earth oxides, and/or other suitable materials.

The epitaxial layer 104 may include a III-V compound semiconductor such as aluminum nitride (AlN), gallium nitride (GaN), indium gallium nitride (InGaN), and indium nitride (InN). As noted above, there may be a lattice constant mismatch between the substrate 102 and the epitaxial layer 104. In order to reduce or eliminate defects caused by lattice constant mismatch, the epitaxial layer 104 grown on the substrate 102 may use a lattice matching layer 106 having a thickness ranging from 5 nm to 100 nm. Adapted to the lattice constant mismatch between the substrate 102 and the epitaxial layer 104. The lattice matching layer 106 may include two or more constituent elements (for example, two constituent elements: a first chemical element and a second chemical element) to form an alloy. The first chemical element can be miscible with the second chemical element in the alloy. The constituent elements constituting the alloy may have a similar crystal structure at room temperature, such as a hexagonal closest packed structure, as shown in Fig. 2A. Each of the constituent elements may have a respective lattice constant, including lattice parameters along the a- axis, b- axis, and c- axis, and lattice parameters of the inter-axis angles α, β, and γ, as shown in FIG. 2B. In addition to the crystal structure, the respective constituent elements constituting the alloy may have similar chemical properties. In one embodiment, both the first chemical element and the second chemical element may belong to the group IV element in the periodic table of elements shown in FIG. 3 (ie, titanium (Ti), zirconium (Zr), hafnium (Hf). ) and 鈩 (Rf)). In this way, the alloy may be made of the elements Ti and Zr, or the elements Ti and Hf, or the elements Zr and Hf, and may have a crystal structure similar to that of the alloy at room temperature, or may be any of them. Made in combination. The alloy may comprise a third chemical element or more elements having a similar crystal structure and similar chemical properties.

There may be a linear relationship between the first chemical element and the second chemical element and their respective lattice parameters associated with each other at normal temperature, such that the lattice constant of the lattice matching layer 106 is approximately equal to the lattice of the epitaxial layer 104. constant. The molar ratio of the first chemical element to the second chemical element is, in atomic percent, from P ₁ to (1-P ₁ ). Since the composition of the alloy will control the lattice parameter values of the resulting alloy, the molar ratio may vary from application to application. In one embodiment, when the epitaxial layer 104 comprises GaN and the alloy comprises Ti mixed with Zr, the atomic percentage P _{Zr of Zr} may be greater than 75% and less than 90%. For example, P _Zr can be about 86%. Therefore, the atomic percentage P _{Ti of Ti} is (1-P _Zr ). One of the first lattice parameters of Zr (for example, the a- axis lattice parameter a _Zr ) is 3.23 Å (Å). One of the second lattice parameters of Ti (for example, the a- axis lattice parameter a _Ti ) is 2.951 Å. As a result, the lattice constant P _A along the a- axis of the alloy is P _Zr × a _Zr + (1-P _Zr ) × a _Ti = 86% × 3.23 + 14% × 2.951 = 3.19 Å, which is approximately equal to when P _GaN = 3.189 Å is the most densely packed GaN a- axis lattice constant P _GaN . The atomic percentage of the first chemical element to the second chemical element may be about 43% to 57% or 99% to 1%, depending on the constituent elements and other factors.

When the epitaxial layer 104 includes different compound semiconductors (for example, AlN, InGaN, InN, and/or other III-V compound semiconductors), the constituent elements of the lattice matching layer 106 and/or the constituent elements of the alloy may be The molar ratio is adjusted such that the lattice constant of the lattice matching layer 106 is adapted to the lattice constant of the epitaxial layer 104. For example, when the epitaxial layer 104 contains AlN and the constituent elements of the lattice matching layer 106 are Zr and Ti, the atomic percentage of Zr can be adjusted to be less than 75% and higher than 50%. In another embodiment using the same constituent elements, when the epitaxial layer 104 contains InGaN, the atomic percentage of Zr may be greater than 90%. In addition to the material of the epitaxial layer 104, the thickness of the epitaxial layer 104 can cause a change in the choice of constituent elements and cause a change in the molar ratio of the respective constituent elements to obtain a 100% lattice match. Although the thickness of the epitaxial layer 104 may vary, the thickness of the epitaxial layer 104 ranges from 5 nanometers to 500 nanometers. In other words, the thickness and material of the epitaxial layer 104 may determine the selection of the respective constituent elements and the molar ratio of the respective constituent elements in forming the lattice matching layer 106. Using any epitaxial technique (eg vacuum evaporation, sputtering, molecular beam epitaxy and pulsed laser deposition, metal organic chemical vapor deposition, atomic layer deposition and/or any other suitable epitaxial deposition method), epitaxial Layer 104 is epitaxially grown on lattice matching layer 106 to transfer the crystalline pattern of lattice matching layer 106 to epitaxial layer 104. One of the following deposition techniques can be utilized at the bottom layer (eg, A lattice matching layer 106 is formed on the plate 102): for example, vacuum evaporation, sputtering, molecular beam epitaxy and pulsed laser deposition, atmospheric pressure chemical vapor deposition, and atomic layer deposition.

Because for some optoelectronic devices and power semiconductor applications, the hexagonal closest packed phase (alpha phase) has the potential advantage over the body centered cubic phase (β phase), it may be desirable to grow the epitaxial layer 104 with an alpha phase to A crystalline pattern similar to the lattice matching layer 106 is achieved. Figure 4 shows the correlation between the alpha-beta phase transition temperature and the atomic percentage of Zr and Ti, according to an exemplary embodiment. For example, when P _Zr is 50%, P _Ti =1-P _Zr = 50%, and the α-β phase transition temperature is about 605 degrees Celsius. When P _Zr is 84% (this example has been exemplified above), the α-β phase transition temperature may be about 780 degrees Celsius. In one of the applications of the multi-quantum-well (MQW) device on the epitaxial layer 104 (for example, an ultra-high brightness light-emitting diode), it can be performed in a temperature range of 700 degrees Celsius to 850 degrees Celsius. Epitaxial deposition methods (eg, metal organic chemical vapor deposition and atomic layer deposition and/or any other suitable method for epitaxial growth). In the present embodiment, when the α-β phase transition temperature is in the range between 700 degrees Celsius and 780 degrees Celsius, the multilayer substrate structure can be heated by any heating method/heat source to crystallize the lattice matching layer 106. The pattern is transferred to the epitaxial layer 104 in an alpha phase while avoiding the occurrence of a beta phase transition. Next, since the epitaxial layer 104 has been formed, and the epitaxial layer 104 is permanently set to the alpha phase; therefore, during subsequent quantum well growth, the temperature used to heat the multilayer substrate structure and to heat any additional component layers It can be raised above 780 degrees Celsius or below 780 degrees Celsius. The temperature can be raised initially to a temperature higher than the α-β phase transition temperature and then immediately lowered below the α-β phase transition temperature to generate a phase change free energy such that the crystal is formed in a large lateral region, and thereby A single crystal alpha phase is obtained in the lattice matching layer.

By employing the lattice matching layer 106, the stress can be reduced and thereby contribute to the growth of the epitaxial layer 104 of a high crystalline quality, which may otherwise be due to the lattice between the substrate 102 and the epitaxial layer 104. The difference in the constant occurs in the epitaxial layer 104 formed during epitaxial growth. If the stress cannot be released by the lattice matching layer, the stress can cause defects in the crystal structure of the epitaxial layer 104. The defects of the crystal structure of the epitaxial layer 104, in turn, make it difficult for the high quality crystal structure to be generated in the epitaxial process for the growth of any subsequent elements. The lattice matching layer 106 is also disclosed in U.S. Patent Application entitled "Crystal Matching Layer for Use in a Multi-Layer Substrate Structure".

As noted above, substrate 102 can comprise: a semiconductor material, a compound semiconductor material, or another type of material (eg, a metal or a non-metal). In certain embodiments, the substrate 102 can be in the form of a polycrystalline solid. In a polycrystalline substrate, replacing a single crystal with a polycrystal will adversely affect the lattice matching layer 106, and thus expand between the lattice matching layer 106 and the epitaxial layer 104 (in a plurality of crystal grains and a plurality of crystal orientations) The difference in lattice constant of an average lattice constant) and the resulting defects (such as threading dislocation or grain boundaries), which in turn leads to deterioration of the crystal quality of the epitaxial layer 104. To reduce or eliminate this negative effect of the polycrystalline substrate, an amorphous layer 108 can be employed between the polycrystalline substrate 102 and the lattice matching layer 106, as shown in FIG. 1B. By adding the amorphous layer 108 between the polycrystalline substrate 102 and the lattice matching layer 106, the influence of the polycrystalline substrate 102 on the lattice matching layer 106 can be reduced. As a result, only the crystal form of the lattice matching layer 106 is transferred to the epitaxial layer 104. The amorphous layer 108 may include, but is not limited to, hafnium oxide, tantalum nitride, tantalum nitride, boron nitride, tungsten nitride, glassy amorphous carbon, tantalate glass (eg, borophosphosilicate glass). And one of the other suitable materials. The amorphous layer 108 may have a thickness of 5 nm to 100 nm.

In some embodiments, the coefficient of thermal expansion of the substrate 102 can be different than the coefficient of thermal expansion of the layers described above, thereby causing large substrate bending. For example, when the coefficient of thermal expansion of the substrate 102 is greater than the coefficient of thermal expansion of the layer, biaxial compressive strain may occur (eg, when the substrate contains sapphire). When the coefficient of thermal expansion of the substrate is less than the coefficient of thermal expansion of the layer, tensile strain occurs (e.g., when the substrate contains germanium). In order to overcome the disadvantages caused by the thermal expansion coefficient mismatch, the substrate can be used as a thermal matching layer 102a (see FIGS. 1C and 1D) by including certain chemical elements on the substrate to adapt to the substrate (in this case). In the embodiment, the thermal mismatch between the thermal matching layer 102a) and the lattice matching layer 106 shown in FIG. 1C, or the thermal mismatch between the substrate and the amorphous layer 108 shown in FIG. 1D. In one embodiment, the thermal matching layer 102a can comprise molybdenum or a related alloy thereof. The coefficient of thermal expansion of molybdenum is about 5.4 x 10 ^-6 /K, which is approximately equal to the coefficient of thermal expansion of certain III-V compound semiconductors (such as GaN). A variety of methods for growing metals, crystals, and alloys thereof can be utilized to fabricate substrates. Examples thereof may include Czochralski, float zone (FZ), directional solidification (DS), zone melt recrystallization (ZMR), sintering, isostatic pressing ( Isostatic pressing), electrochemical plating, plasma torch deposition, and/or other suitable methods. The thickness of the heat matching layer 102a is in the range of 5 nm to 1 mm.

By using a thermal matching layer and a lattice matching layer, the strain caused by thermal expansion mismatch and lattice mismatch can be reduced or completely eliminated. Therefore, the dislocation density in the resulting epitaxial layer 104 can be less than 10 ² /cm ² (<100 dislocations per square centimeter). In the development of light emitting diodes (LEDs), reducing or eliminating strain can meet the need to overcome the so-called "green gap.""Greengap" is an industrial term for LED light output from a multi-quantum well light-emitting diode (in a multi-quantum well light-emitting diode, in which indium is alloyed with GaN to form a green light-emitting diode). Reduce or decrease. In a component area of 1 to 5 square millimeters, when the forward current is greater than 50 milliamperes, due to excessive strain of the substrate, stress-induced extension defects, and point defects diffused into the active multiple quantum well device layer The defect density, such a decrease in the output of the green light.

Since the human eye is most sensitive to green and the green light strongly affects human perception of white light quality, this embodiment is capable of growing high crystal quality components on layer 104. Moreover, exemplary embodiments of the present invention can provide a cost effective way of fabricating a green light emitting diode crystal template. Therefore, the achievement of the "green gap" enhances the high-performance of the white light-emitting diode based on the mixed light of red, green and blue, which is compared with the phosphor-based down conversion luminescence used today. The diode has the highest theoretical efficiency.

Figure 5 illustrates an example of "example," "example," as used herein, "as an example, instance, or illustration" for depositing a film on a substrate. System 500. To facilitate epitaxial deposition of a film 502 on a substrate 504 in a lateral direction A, a lateral control shutter 506 is used and a lateral control shutter 506 is disposed between the substrate 504 and a material source 508. Material source 508 is used to deposit the source material onto the surface of the substrate using a suitable deposition method. Depending on the deposition method utilized, the source material may be vaporized from a solid source or liquid source to an atomic or molecular form and delivered to the substrate as a vapor via a vacuum or low pressure gas or plasma environment. The gasification material can be an element, an alloy or a compound in various charged states. When the gasification material has a mean free path greater than one meter, the trajectory of the vaporized material can be considered a direct line-of-sight. Therefore, the deposition process utilized is defined as line of sight deposition. The line of sight deposition method may be physical vapor deposition or chemical vapor deposition, including vacuum evaporation, sputtering, pulsed laser deposition, molecular beam epitaxy, atomic layer deposition, atomic layer epitaxy, plasma torch deposition, and/or Any other suitable method. The chemical vapor deposition can be atmospheric pressure chemical vapor deposition and/or any other suitable chemical vapor deposition method. Depending on the source structure, vacuum evaporation includes thermal evaporation, laser beam or spot lamp evaporation, arc discharge evaporation and electricity. The beam is evaporated. Similarly, depending on the source configuration, the sputtering method can include one of DC sputtering, magnetron sputtering, RF sputtering, and pulsed laser sputtering.

In any of the above deposition methods, the distance L1 between the material source 508 and the substrate 504 can be less than the mean free path of the gas molecules, thus allowing most of the molecules in the gas to arrive in a collimated manner. To uniformly form the film 502 on the surface of the substrate 504, the distance L2 between the lateral control shutter 506 and the substrate surface may be less than the mean free path of the gas molecules. In this case, the mean free path is defined as the average distance traveled by one gas molecule before colliding with another gas molecule. The substrate 504 may include hafnium oxide, tantalum nitride, amorphous boron nitride, amorphous tungsten nitride, glassy amorphous carbon, amorphous rare earth oxide, amorphous zinc oxide, and bismuth hydrochloric acid glass.

Different deposition processes can have different flux angular distributions at the substrate. There are a number of ways in each deposition process that help to improve the angular distribution at the substrate. Taking a sputtering deposition process as an example, in a typical sputtering deposition process, most of the atoms that strike the substrate may not strike the substrate at a normal incident angle, because the atoms are from the material source (ie, the sputtering target). ) is emitted at a cosine angle, as shown in Figure 6A. To form an angular distribution closer to the normal at the substrate, a collimator can be used and placed between the substrate and the sputter target in a magnetron sputtering system. The collimator is used to reduce the illogical flux from the sputter target, thereby enhancing the orientation of the deposit. The angular distribution of the collimated incidence is shown in Figure 6B. In an ion assisted deposition process, one of the sputtered atoms is partially ionized. The plasmad atoms can be concentrated near θ = 0 degrees to form a directed angular distribution (eg, orientation angle distribution 602) while the neutral species typically has a cosine angle distribution 604. The overall angular distribution is considered as a superposition of the cosine and the orientation angle distribution, as shown in Figure 6C.

In a vapor deposition process, the angle of incidence of the material vaporized onto the substrate can affect the film Quality, crystal orientation and other characteristics. Depending on the angular distribution of the incident atomic flux produced by the material source and the desired angular distribution of the atoms at the substrate, the vaporized material can be deposited onto the substrate surface at normal or incident angles. Referring again to Figure 5, the source material can be deposited at an angle of incidence of -15 degrees to +15 degrees. The average angle of incidence of the deposited atomic flux may vary depending on the deposition geometry, the type of gasification source, and the relative motion between the substrate and the source of the material.

As shown in Figure 5, the lateral control shutter 506 is used to control the growth of the film. The lateral control shutter 506 can define a lateral boundary (not numbered) of the deposited film 502 and cover certain predetermined portions of the substrate 504 to prevent deposition of source material onto portions of the substrate surface. In operation, the lateral boundary of the deposited film 502 is moved and controlled by moving one of or the other of the laterally controlled shutter 506 or substrate 504 to advance the growth edge of the film, thereby facilitating lateral orientation on the substrate. Epitaxial deposition. In one example shown in FIG. 5, the lateral control shutter 506 is moved relative to the substrate 504 in direction A. In another example, the lateral control shutter can remain stationary and the substrate moves relative to the lateral control shutter. In yet another example, the laterally controlled shutter and the substrate can be moved at different speeds to achieve relative motion therebetween. System 500 can also include a drive system (not shown) to control the relative movement of the lateral control shutter to the substrate. System 500 can include a drag control shutter 512 that is used to help obscure any unnecessary deposits on the single crystal left behind the growing edge of film 502. The latter helps maintain a uniform film thickness on film 502. If a drag control shutter is used, the drag control shutter 512 can be configured to avoid further epitaxy deposition onto the newly crystallized film 502 on the substrate 504.

Since the properties of many films, such as the particle size of the deposited material deposited on the substrate, are affected by the deposition temperature, temperature control is desired. Depending on the deposition method used, system 500 can include different types of heat sources (eg, heat source 510 in FIG. 5) to control substrate temperature and / or provide elevated temperatures that can be used in the deposition process. For example, in a vacuum deposition process, a heat source is typically used to heat gasify the source material, desorb the deposited material from the target surface, heat the substrate for cleaning and subsequent processing, melt the source material, and The thermal kinetic energy is increased on the surface of the substrate or the surface mobility of the adatom or molecule participating in the deposition process is enhanced. Heat can be generated in a vacuum chamber by a number of different techniques. In an example of a sputter deposition process, the substrate can be heated by ion bombardment, electron, optical radiation, induction heating, or other heating techniques. The heat source can be embedded in the system or external to the system. Exemplary heat sources can include a radiant heater (infrared heating, laser, etc.), hot wire radiant heating, focus lamp heating, induction heating, direct metal pedestal heaters, or ceramic pedestal heaters.

When a film of a single crystal material is deposited on a substrate, epitaxial growth occurs, and when a single seed is isolated on the surface of the substrate or when the substrate is a single crystal, it can be replicated as a growth material. The crystal structure of the substrate. Since the lateral growth of the crystal plays an important role in determining the material properties (eg, the dislocation density and strain caused by the lattice mismatch between the deposited material and the substrate), a lateral control shield can be used to promote the deposition of the material along the Epitaxial growth in the transverse direction. Due to a lateral control of the relative movement between the shutter and the substrate, at the beginning, epitaxial growth occurs in a direction substantially orthogonal to the surface of the substrate (eg, in a vertical direction), and then along substantially parallel to the surface of the substrate The direction (eg, in a parallel direction) is grown. A lateral crystal epitaxial growth is illustrated in Figure 7A. In FIG. 7A, the lateral control shutter 706 is moved from the left end 712 of the substrate toward the other end of the substrate (not shown), thereby causing epitaxial growth to begin from the left end 712. A plurality of grains at a plurality of points on the left end 712 can be grown and used as seed crystals for subsequent crystal growth. The crystal grows vertically in the beginning. As the lateral control shutter 706 moves relative to the substrate, the crystal can grow in both the lateral and vertical directions.

The particle size of the deposited film plays an important role in its electronic properties. As the particle size increases, the number of grain boundaries per unit area and the number of boundary interfaces decrease. For example, high density grain boundaries (eg, small particle sizes or extended defects in the crystal structure) reduce the conductivity and thermal conductivity of the deposited film. Therefore, it is desirable to increase the particle size as much as possible. An exemplary embodiment of obtaining a minimum grain boundary and a minimum number of grains on a substrate is illustrated in Figures 7B-7D.

As shown in FIG. 7B, the lateral control shutter 706 is disposed between the substrate (not shown) and the source of material (not shown) and covers a portion of the substrate leaving an area (eg, region 714) exposed thereto. Material source. Region 714 can have a sharp corner or an edge. In this embodiment, the sharp angle is the angle of the substrate formed by adjusting the lateral control shutter and the placement of the substrate. By this arrangement, a self-selected seed 716 can be grown at the sharp corner. This grain acts as a crystal to initially crystallize and provides a point at which deposition begins. As the lateral control shutter 706 and the substrate move relative to each other in the lateral direction, the crystal grows both in the vertical direction and the lateral direction on the entire surface of the substrate. In another example, more than one type of grain may be grown at the sharp corners, and lateral advancement helps drive the grain boundaries in an outward direction, thereby effectively forming a very large lateral dimension over the entire substrate. The minimum number of grains.

In one embodiment shown in FIG. 7C, the substrate surface may be formed by patterning epitaxy during deposition of the film on the surface of the substrate or during recrystallization of the molten material on the surface of the substrate. A portion has a pattern to form a long-range order, thereby forming a surface relief structure (eg, surface relief structure 720). The surface relief structure 720 can serve as a template for growing a grain on the substrate and causing a desired crystal orientation in the newly grown film. Then using the grain to initiate crystallization and Used to provide an origin for the deposition of the deposited film. Similar to the embodiment shown in FIG. 7B, as the relative movement between the lateral shield 506 and the substrate in the lateral direction, the single crystal grains grow simultaneously in both the vertical and lateral directions on the entire surface of the substrate. The surface relief structure 720 can be fabricated by various lithography techniques such as photolithography, electron beam lithography, nanoimprint lithography, or focused-ion-beam (FIB) lithography. And/or any other suitable lithography technique. Alternatively, the surface relief structure 720 can also be transferred or added to the corners of the substrate or the edges of the substrate by a laser heating process or ablation. In this embodiment, the seed crystals may protrude outward in the plane of the substrate as the growing edge advances away from the corner.

In addition to the surface relief structure 720, a crystal 722 can be added to one of the substrates, such as a corner of the substrate. The seed crystal can be used for initial crystallization and provides an origin at which deposition of the deposited film begins. Similarly, as the growing edge advances away from the corner, the added seed crystal can protrude outwardly in the plane of the substrate.

Similar to FIG. 7B, FIG. 7D illustrates that a die begins to grow laterally outward at a sharp corner of one of the regions 724 of the substrate, wherein the region is exposed to a source of material. Compared with FIG. 7B, in the present embodiment, the sharp angle is not made by adjusting the placement of the substrate and the lateral control shutter. Instead, the sharp corner is formed by shielding the baffle with one of the shapes. A grain can be grown at the sharp corners, and the grain is initially crystallized as a crystal and provides an origin for the deposition to begin. An additional advantage of using one of the illustrated triangles, or a crescent having the same curvature, is that the grain boundaries will grow perpendicular to the shape of the edge of the baffle by grain competition. As the growing edge moves forward away from the seed crystal, this will necessarily cause any grain parallel to the plane of the substrate to grow wider.

In the above embodiments, the shielding plate can have various shapes according to different applications. shape. For example, as shown in FIG. 7D, the shielding plate may have a polygonal shape or a circular arc shape. A portion of the perimeter of the polygon defines a shape having a sharp corner at which the seed crystals are grown. The baffle can be rectangular, square, circular, triangular, crescent shaped or a "herringbone" shape and/or any other suitable shape. The mask can be used for any epitaxial film growth in which the crystal can be allowed to grow in both the lateral and vertical directions on a substrate. For example, a mask can be used to grow a lattice matching layer in a multilayer substrate structure.

The various modifications and other examples of the embodiments described herein will be apparent to those skilled in the <RTIgt; Therefore, it is to be understood that the embodiments are not limited to the particular embodiments disclosed, and are intended to include modifications and other embodiments. In addition, while the above description and the associated drawings are illustrative of various example embodiments in the context of some example combinations of elements and/or functions, it should be understood that they may be substituted without departing from the scope of the appended claims. The embodiments provide different combinations of elements and/or functions. In this regard, for example, various combinations of the various components and/or functions may be included in the various aspects of the accompanying claims.

100‧‧‧Multilayer substrate structure

102a‧‧‧Hot matching layer

104‧‧‧ epitaxial layer

106‧‧‧ lattice matching layer

108‧‧‧Amorphous layer

Claims (36)

A multi-layer substrate structure comprising: a substrate having at least a portion of a pattern to form a surface relief structure, thereby causing a desired crystal orientation during formation of a deposited film, wherein the surface relief structure acts as a template for growing a grain on the substrate, wherein the grain is used for initial crystallization and provides an origin for depositing the deposited film; and a lattice matching layer is formed on the substrate The lattice matching layer comprises: a first chemical element having a hexagonal closest packed structure at room temperature, and the hexagonal closest packed structure is at an α-β phase transition higher than room temperature Transitioning to an integral core-cubic structure at a temperature, the hexagonal closest packed structure of the first chemical element having a first lattice parameter; and a second chemical element having a hexagonal maximum at room temperature a densely packed structure having a chemical property similar to the first chemical element, the hexagonal closest packed structure of the second chemical element having a second lattice parameter, the second chemical element being Miscible to form a chemical element having a hexagonal closest packed at room temperature for the alloy, wherein the alloy is one of the lattice constant approximately equal to the lattice constant of the compound semiconductor member of one of one of the Group III-V. The multi-layer substrate structure of claim 1, wherein at a constant temperature, there is a linear relationship between the first chemical element and the second chemical element and their respective associated lattice parameters to allow the lattice constant of the alloy to be approximately equal to The lattice constant of this member of the III-V compound semiconductor. The multi-layer substrate structure of claim 1, wherein the first chemical element and the second chemical element are at least One of them belongs to the group IV element in the periodic table. The multi-layer substrate structure of claim 1, wherein the molar ratio of the first chemical element to the second chemical element is about 14% to 86% in atomic percent. The multilayer substrate structure of claim 1, wherein the molar ratio of the first chemical element to the second chemical element is about 43% to 57% by atomic percent. The multilayer substrate structure of claim 1, wherein the molar ratio of the first chemical element to the second chemical element is about 99% to 1% by atomic percent. The multi-layer substrate structure of claim 1, wherein the lattice matching layer further comprises a third chemical element, wherein the third chemical element has a crystal structure similar to the first chemical element and the second chemical element and a similar chemistry a property, and wherein the third chemical element is miscible with the first chemical element and the second chemical element to form an alloy, at a constant temperature, at the first chemical element, the second chemical element, and the third chemical There is a linear relationship between the elements and their respective associated lattice parameters to allow the lattice constant of the alloy to be approximately equal to the lattice constant of the member of the III-V compound semiconductor. The multilayer substrate structure of claim 1, wherein the III-V compound semiconductor comprises one of aluminum nitride (AlN), gallium nitride (GaN), indium gallium nitride (InGaN), and indium nitride (InN). The multi-layer substrate structure of claim 1, further comprising a thermal matching layer formed on the substrate, the thermal matching layer comprising molybdenum, molybdenum-copper, mullite, sapphire, graphite, aluminum oxynitride, antimony, At least one of tantalum carbide, zinc oxide, and rare earth oxide, wherein the thermal expansion layer has a coefficient of thermal expansion that is approximately equal to a coefficient of thermal expansion of a member of the group III-V compound semiconductor. The multi-layer substrate structure of claim 1, further comprising an amorphous layer between the thermal matching layer and the lattice matching layer, wherein the amorphous layer comprises ceria, tantalum nitride, boron nitride, tungsten nitride, nitrogen One of bismuth, glassy amorphous carbon and silicate glass. A method of fabricating a multilayer substrate structure, the multilayer substrate structure comprising: a substrate having at least a portion of the substrate having a pattern to form a surface relief structure, thereby causing a desired crystal during formation of a deposited film Orientation, wherein the surface relief structure acts as a template for growing a grain on the substrate, and wherein the grain is used for initial crystallization and provides an origin for depositing the deposited film; and a crystal a lattice matching layer formed on the substrate, the lattice matching layer comprising: a first chemical element having a hexagonal closest packed structure at room temperature, the hexagonal closest packed structure being higher than Converting to an integral core-cubic structure at one of the room temperature α-β phase transition temperatures, the hexagonal closest packed structure of the first chemical element having a first lattice parameter; and a second chemical element, the second chemical element Having a hexagonal closest packing structure at room temperature and having a chemical property similar to the first chemical element, the hexagonal closest packing structure of the second chemical element having a second lattice The second chemical element may be miscible with the first chemical element to form an alloy having a hexagonal closest packing structure at room temperature, wherein one of the alloys has a lattice constant approximately equal to that of the III-V compound semiconductor One of the members has a lattice constant. The method of claim 11, further comprising: forming a thermal matching layer, the lattice matching layer is grown on the thermal matching layer, the thermal matching layer comprising molybdenum, molybdenum-copper, mullite, sapphire, At least one of graphite, aluminum oxynitride, cerium, lanthanum carbide, zinc oxide, and rare earth oxide. The method of claim 11, further comprising a coefficient of thermal expansion of the first chemical element along a plane The second chemical element is interpolated along a thermal expansion coefficient of the plane to obtain a first-order estimate of the thermal expansion coefficient of the alloy along the same plane, wherein the thermal expansion coefficient of the alloy is about III-V compound semiconductor The coefficient of thermal expansion of the member along the same plane. The method of claim 11, further comprising: heating the multilayer substrate structure to a temperature lower than an α-β phase transition to allow epitaxial growth of an epitaxial layer on the lattice matching layer with the correct α phase. The method of claim 11, further comprising: heating the multilayer substrate structure to a temperature higher than an α-β phase transition temperature and immediately lowering the temperature lower than the α-β phase transition temperature, so that a phase change free energy is generated to make a large lateral direction The region is crystallized, whereby a single crystal α phase is obtained in the lattice matching layer. A method of forming a deposited film on a substrate, comprising: directing a source material from a material source to a surface of the substrate by a line of sight deposition method; and forming a shielding plate between the substrate and the source material Blocking a predetermined portion of the substrate to form a barrier substrate portion and an unblocked substrate portion, thereby preventing source material from being deposited onto the initial blocked portion of the substrate; and locating the mask with the substrate Relative movement between the portions of the substrate to be reduced and the portion of the unblocked substrate being enlarged, thereby forming a moving lateral growth boundary, thereby achieving lateral epitaxial growth on the substrate to form the deposited film, wherein At least a portion of the substrate has a pattern to form a surface relief structure that in turn causes a desired crystal orientation during formation of the deposited film, wherein the surface relief structure acts as a crystal for growth on the substrate a template of particles, and wherein the grains are used for initial crystallization and provide an origin for the deposition of the deposited film. The method of claim 16, further comprising: using one or more dies as the dies on the substrate Crystals are grown on. The method of claim 16, wherein the unblocked substrate portion of the substrate has a sharp corner; and the method further comprises: growing the seed grain around the sharp corner. The method of claim 16, further comprising: causing at least a portion of the substrate to have the pattern by applying a lithography process, a laser heating process, and ablating one of them. The method of claim 16, further comprising adding the seed crystal to a desired location on the substrate. The method of claim 16, further comprising: blocking a second portion of the substrate by a drag control shutter to control or avoid forming on the portion of the substrate that is blocked by the drag control shutter Epitaxial deposition was performed on the deposited film. A system for forming a deposited film on a substrate, comprising: a lateral control shutter disposed between the substrate and a source material and configured to block a portion of the substrate to prevent deposition of the source material to The blocked portion of the substrate, wherein the lateral control shutter and/or one of the substrates moves relative to the other to form a moving lateral growth boundary edge, thereby achieving lateral epitaxial deposition on the substrate And forming a deposited film having a large particle diameter on a surface of the substrate, wherein at least a portion of the substrate has a pattern to form a surface relief structure, thereby causing a desired crystal in the process of forming the deposited film Orientation, wherein the surface relief structure acts as a template for growing a grain on the substrate, and wherein the grain is used for initial crystallization and provides an origin for the deposition film to begin to deposit. The system of claim 22, further comprising a towed control shutter, wherein the size of the opening between the lateral control shutter and the trailing control shutter is adjusted such that the deposited film has a desired uniform thickness. The system of claim 22, wherein the lateral control shutter has a baffle edge, and the shape of the baffle edge is rectangular, square, circular, triangular, crescent, chevron, straight edge, arc, and One of the polygons. The system of claim 22, wherein the source material is positioned relative to the lateral control shutter to deposit the source material to the surface of the substrate using a line of sight deposition method. The system of claim 22, further comprising a collimator, wherein the straightener is disposed between the source material and the substrate. The system of claim 22, further comprising a heat source comprising an infrared heater, a hot wire radiant heater, a laser, a focus lamp heater, a grating charged particle beam, an induction heater, and a One of a direct metal base heater and a ceramic base heater. A method of forming a deposited film on a substrate, comprising: directing a source material from a material source to a surface of the substrate by a line of sight deposition method; and forming a shielding plate between the substrate and the source material Blocking a predetermined portion of the substrate to form a blocked substrate portion and an unblocked substrate portion, thereby preventing source material from being deposited onto the initial blocked portion of the substrate; and causing the mask to The substrate is relatively moved such that the blocked substrate portion is reduced and the unblocked substrate portion is enlarged, thereby forming a moving lateral growth boundary, and then lateral epitaxial growth is performed on the substrate to form the deposited film. At least a portion of the substrate has a pattern to form a surface relief structure, thereby causing a desired crystal orientation in forming the deposited film, wherein the surface relief structure acts as a template for growing a grain on the substrate And wherein the grain is used for initial crystallization And provide an origin for the deposition of the deposited film. The method of claim 28, further comprising: growing crystals on the substrate by using one or more crystal grains as the crystal grains. The method of claim 28, wherein the unblocked substrate portion of the substrate has a sharp corner; and the method further comprises: growing the seed crystal around the sharp corner. The method of claim 28, further comprising: causing at least a portion of the substrate to have the pattern by applying a lithography process, a laser heating process, and ablating one of them. The method of claim 28, further comprising adding the seed crystal to a desired location on the substrate. The method of claim 28, further comprising: blocking a second portion of the substrate by a drag control shutter to control or avoid forming on the portion of the substrate that is blocked by the drag control shutter Epitaxial deposition was performed on the deposited film. The method of claim 28, further comprising: utilizing a collimator disposed between the source material and the substrate to straighten the source material. The method of claim 28, wherein the line of sight deposition method comprises one of physical vapor deposition and chemical vapor deposition. The method of claim 28, further comprising: heating the substrate by one of infrared heating, hot wire radiant heating, laser, focus lamp heating, induction heating, direct metal pedestal heater, and ceramic pedestal heater.