TWI293774B - Wafer carrier for growing gan wafers - Google Patents

Description

1293774 IX. INSTRUCTIONS OF THE INVENTION: TECHNICAL FIELD OF THE INVENTION The present invention relates to the fabrication of semiconductor materials and devices, and more particularly to an apparatus for growing epitaxial layers of materials such as gallium nitride. [Prior Art] A semiconductor wafer is often placed by placing a wafer (also referred to as a substrate) in a reaction chamber of a chemical vapor deposition (CVD) reactor and then growing one or more Lei on the wafers. The crystal layer is manufactured. During this process, wafers are placed in the CVD reactor and a quantity of controlled gas is introduced at a controlled rate on the wafers in order to grow epitaxial layers on the wafers. Reactant chemical. CVD reactors are available in a variety of designs, including: horizontal reactors in which the wafer is mounted at an angle to the incoming reactant gas; a planetary self-rotating horizontal reactor in which the reactant gases are passed across the wafer And a vertical reactor in which the wafers are rotated at a relatively high rate in the reaction chamber while the reactant gases are being injected down onto the wafers. The reactant chemicals are generally placed by placing the reactant chemicals in a device (referred to as a water jet) and then passing a carrier gas through the water jet. The reaction chamber is introduced as a precursor. The carrier gas picks up the reactant chemistry molecules to provide a reactant gas and then feeds the reactant gas into the reaction chamber of the CVD reactor using a layer flow controller. The conditions under which the reactant gases are introduced into the reaction chamber have a significant effect on the characteristics of the epitaxial layer grown on the aa circle such as 100085.doc 1293774. These conditions may be modified to optimize the properties of the epitaxial layer grown on the wafers, typically including concentration, vapor pressure, flow paths of the reactant gases, chemical activity, and temperature. For example, by changing the design of the flow flange for introducing reactant gases into the reaction chamber, the flow path of the reactant gases can be varied. In many cases, the properties of the epitaxial layers grown on the substrates are investigated to determine the optimal flow path for growing a particular type of layer. When depositing an epitaxial layer on a wafer, the wafers are typically placed on a wafer carrier in a reaction chamber, which in turn may be placed on a rotatable susceptor. At Emc〇re, Inc., Somerset, NJ, developed a special alpha re-meter that heats the susceptor and heats the susceptor by a heat source (eg, a resistive wire or a resistive lamp) located below the susceptor Round carrier. In these reactors, the growth of the uniform epitaxial layer is achieved by rapidly rotating the wafer carrier and the susceptor on which the wafers are mounted. The thickness, composition and quality of the deposited layer determine the characteristics of the resulting semiconductor device. Therefore, the deposition process must be able to deposit a film of uniform composition and thickness on the front side of each wafer. With the use of larger wafers, and with the simultaneous use of devices that deposit coatings on several wafers, the need for uniformity is becoming more stringent. In a deposition process using a conventional wafer carrier, due to thermal resistance generated by the susceptor, an interface between the wafer and the wafer carrier, and a material for forming the susceptor, the aa circular carrier, and the wafer The different emissivity, so the surface temperature of the wafers is generally cooler than the surface temperature of the wafer carrier. Unfortunately, this temperature difference reduces the quality of the resulting semiconductor wafer. For example, the higher temperature of the surface of the wafer carrier causes the temperature on the surface of the wafer to be less than 100085.doc 1293774 (especially along the outer gj circumference), such that the layer deposited along the peripheral portion of the wafer is generally of poor quality. And the value is limited. Moreover, in a configuration using a pedestal, excessive heating wire power is required to heat the pedestal, thereby subjecting the wafer carrier to heat. In the prior art device shown in Figure 1A, a wafer 1 is mounted on top of a wafer carrier 12. Further, the wafer carrier 12 is mounted on a susceptor 14 mounted on a rotatable support spindle "top. The wafer 10, the wafer carrier 12 and the susceptor 14 The upper end is generally located in a closed reactor chamber. A heating assembly 18 can be disposed under the susceptor 14 to heat the crucible base, the wafer carrier 12 and the wafer cassette mounted on the susceptor. Preferably, the workpiece 6 is rotated such that the uniformity of the reactant gases flowing through the wafers is increased. The rotating mandrel 16 generally causes the uniformity of the reactant gases flowing through the wafer 1 and the entire crystal. The temperature uniformity of the circle is increased. The wafer carrier 12 includes a circular reservoir 20 on its upper surface 22 to hold the wafer cassette in place during rotation of the wafer carrier 12 during the deposition process. The diameter of the circular receptacles 20 is about 0.020 greater than the diameter of the wafer, and the depth is about 〇 (8) 2" greater than the thickness of the wafers. The wafer carrier 12 also typically includes an annular flange 24 for lifting the wafer carrier 12 and transporting the wafer carrier 12 into and out of the reaction chamber. On the bottom surface thereof, the wafer carrier 12 may include an annular wall 26 for positioning and holding the wafer carrier 12 on the susceptor 14 when the wafer carrier is rotated during the deposition process. Referring to FIG. 1B, wafer 10 is heated by heating assembly 18 during the deposition process. Therefore, the temperature of the earlier deposited stupid layer is generally two more than the later deposited meerkat layer of 100085.doc 1293774. This situation often causes the peripheral edge 28 of each wafer to be distorted (i.e., rolled up and away from the wafer carrier 12) from the wafer carrier 12, as shown. Thus, the peripheral edge 28 of the wafer 10 is no longer in contact with the wafer and is again heated to the same level of heating as the inner portion of the wafer. ^B The present invention is not limited by any particular theory of operation, but we are convinced that the 5 ray distortion is due to the fact that the bottom temperature of the wafers is higher than the top temperature of the wafers or because it is placed during growth. Caused by other stresses on the wafers. In addition, when the curled outer portion of the wafers is moved away from the heating assembly due to the twisting of the wafer, the inner portions of the wafers are heated, so that the wafers are heated unevenly. Therefore, the stray layers are not uniform over the entire crystal, and the distortion of the wafer 10 must be discarded. One reason for this is that the operational characteristics of the semiconductor devices taken from the outer portions of the warped wafers will be different from the semiconductor devices taken from the inner regions of the wafers. Another problem with the configuration shown in Figures 1A and 1B is that the base (4) prevents effective heating of the crystal carrier 12. This is a problem when it is necessary to obtain a relatively high temperature (10), for example, when growing a gallium nitride crystal If] 0 main, ^ ^ day HJ). At high temperatures, the heating wire may melt or deform. Therefore, there is a need for a device that can deposit a more uniform layer on top of the entire surface of each crystal. More specifically, there is a need for a wafer apparatus that will maintain the wafers substantially flat during the formation of the wafer layer to prevent curling of the wafer edges. In the case of the configuration, wherein the heating element directly heats the wafer carrier, and/or a pedestal or other object is located between the heating element and the wafer carrier 100085.doc 1293774. This configuration allows the temperature of the heating wire to be maintained at a lower level while still heating the wafer carrier to a sufficient level. SUMMARY OF THE INVENTION The present invention discloses an apparatus for growing an epitaxial layer on a wafer, and more preferably a device for growing a gallium nitride wafer. The present application incorporates one or more of the concepts in the concept of the U.S. Patent Application Serial No. 09/619,254, filed on Jul. 19, 2000, the disclosure of which is hereby incorporated by reference.

It is an object of the present invention to address the problems that arise with certain prior art devices. Specifically, in prior art devices, a pedestal is used to support the wafer carrier. The susceptor is typically positioned between the wafer carrier and a heating wire for heating the wafer carrier. According to those skilled in the art, the susceptor captures heat from the heating wire, which requires heating the heating wire to a higher temperature to produce the same wafer temperature. This is because the pedestal draws a portion of the heat and prevents heat from being transferred directly from the heating wire to the wafer carrier. The present invention solves this problem by eliminating the need for the susceptor by using a wafer carrier that is specifically designed to couple to the upper end of a mandrel. The wafer carrier includes a plate having a top surface and a bottom surface, and a central opening having a plurality of hollow, radially extending shafts extending from a central opening to an outer circumference of the plate. In a particular preferred embodiment, a grinder is used to create the central opening. A drill can be used to bring the hollow, radially extending shafts, wherein each shaft is drilled from the outer circumference of the plate I to the central opening. The wafer carrier also includes a continuous doorway that is completely milled through the plate for receiving wafer carrier discs with 100085.doc -10- 1293774. Each such sigma is specifically designed to support - a substantially porous disc. The porous disks are held in the wafer carrier openings by fixing rings to the plates (by holding the fixing members such as screws to hold the fixing plates). Preferably, the center opening has a separating member inserted therein. The separating member includes a central hub made of a material that does not diffuse into the core shaft material and thus does not adhere to the core shaft. For example, the center hub may be made of graphite or other Tauman material that does not diffuse into a mandrel made of molybdenum. In operation, the wafer carrier is placed on the upper end of the mandrel by aligning the central opening with the top of the mandrel. The wafer is positioned on the porous disk of the wafer carrier before or after the wafer carrier is placed in a reaction chamber. A vacuum is then drawn, possibly via the mandrel, and in turn through a central opening of the wafer carrier and a hollow, radially extending mandrel in communication with the central opening. The vacuum is then drawn through the porous disks to prevent the edges of the wafer substrate from twisting during an epitaxial growth process. As mentioned above, the device does not have an object such as a pedestal between the wafer carrier and the heating wire. Therefore, heating the wafer carrier ' directly by the heating wire does not waste excessive heat by heating an additional object such as a susceptor. Therefore, when growing the gallium nitride wafer, a preferred temperature of 1,5 〇0C is obtained on the top surface of the wafer carrier, and the heating wire only needs to be heated to about 1,900 to 2,0 〇. Hey. Conversely, if there is an object such as a pedestal between the wafer carrier and the far-heating line, then the study shows that 'the desired ibQOC is to be obtained on the top surface of the wafer carrier, which must be 100085.doc - 11 - 1293774. At these relatively high levels, the heating wire will be melted and/or heated to about 2,500 to 2,600. C temperature (ie 2,500 to 2,600 ° C), the heating line _ shape 0

Therefore, the present application solves at least two of the growth of the roof layer. The problem is solved by aspirating the vacuum through the porous discs to prevent the edges of the wafers from being distorted, in the case of the US towel No. 09/619,254 filed on July 19, 2000. This problem is discussed and the disclosure of this case is hereby incorporated by reference. Another problem addressed is the use of specially designed devices for the purpose of better heat transfer between the heating wire and the wafer carrier without the presence of objects between the wafer carrier and the heating wire. Wafer carrier. Therefore, it is not necessary to heat the heating wire to a very high temperature (for example, '2'5〇〇 to 2, _. 〇. This is especially advantageous for growth gasification because GaN must grow at a particularly high temperature. Preferably, the mother-substantially porous disc is made of a material selected from the group consisting of graphite, training and turning, and the porosity is preferably about 7 to the deposition to possibly include a core The shaft opening communicates with one of the pumps to create a vacuum or suction within an elongated opening extending through the mandrel. Once a low pressure region is created within the mandrel opening, the central opening of the shawl carrier and the hollow shaft are both Will create a vacuum or low pressure region. Position the wafer on top of the wafer-made porous disk and introduce - or multiple reactant gases into the vacuum opening in the central opening of the carrier Or the suction force is less than the pressure level within the reaction. Thus, a suction is formed at the interface between the wafer and the porous discs. Such suction prevents the circumference of the wafers 100085.doc -12- 1293774 Edge edge when depositing the epitaxial layers The film or carrier is detached from the wafer carrier, as is the case with prior art deposition chambers (e.g., prior art embodiments illustrated in Figure 1A), thereby forming a uniform across the entire surface of the wafer. An epitaxial layer to provide a reliable semiconductor device obtainable from the peripheral regions of the wafers. These and other preferred embodiments of the present invention will now be described in more detail in certain preferred embodiments. The porous element has a porosity of about 7 to 14%. The wafer carrier may be made of a material that can withstand the amount of enthalpy in the reaction chamber (for example, turned, tungsten, group, and tantalum). Made of cranes, buttons and chains. The porous element may be made of a material that can withstand the heat in the reaction chamber (for example, tantalum carbide and graphite). The blind opening π in the plate is preferably centered on the plate. The at least one axial small blind blind extends outwardly. In a particular preferred embodiment, the extended extension is rolled over the seal. The shaft preferably radiates outward from the blind opening to The at least-axis is better The suction is used to draw the true enthalpy to create a suction on the surface of the porous element. In the preferred embodiment, the blind opening of the plate has the same function as the hub. - the upper end of the mandrel is combined. The line is preferably made of a non-diffusing material such as graphite as the other preferred one of the present invention.

The circular carrier comprises, in LA, and also in the ,1, a plate for growing a wafer, which has _筮, μ number of open π, which extends from the surface: the second surface to the second surface a second surface; and 100085.doc -13- 1293774 a porous element, J: in the system, each of the plurality of openings in the open wafer carrying "= pieces: adapted to support - or a plurality of wafers. The surface extends toward the first surface. The blind: the core opening ' extends outwardly from the second opening of the plate, and the plurality of axes 'open from the blind center and one of the holes : having a first end communicating with the blind center opening - the blind end opening is a second end of the two of the two members communicating to provide a flow. The fluid between the elements in the equiaxed / hole 70 Peripheral or multiple components: the yoke may extend around - 哕 blind, n in the porous elements. In operation, the preferred system is to pump through the U and the axes. True m forms a suction on the surface of each of the porous elements I. In the specific embodiment, the π-the-diameter is the first a second diameter is located on the second surface of the plate, and the first diameter is greater than the second diameter. The wafer carrier is preferably further inserted into the first diameter opening in the panel The porous members are fixed in position 151. The dedicated retaining ring is preferably made of a material capable of withstanding heat in the reaction chamber (e.g., molybdenum and tungsten). Another embodiment of the present invention In one example, the t-stack for growing the stupid layer on the wafer includes a rotatable mandrel having an upper end disposed within the reaction and extending between the upper end and the lower end of the mandrel Preferably, the open and the set 4 includes a rotatable wafer carrier fixed to the upper end of the mandrel. The rotatable wafer carrier preferably includes: a plate having a first surface and a first surface a second surface; at least one opening extending from the first surface of the plate to the second surface; a porous member that is placed at least in the opening of the & 100085.doc -14 - 1293774, wherein the porous The component is a plurality of wafers; and a caution door is used to press the fork or - from the first The surface faces the second surface, the blind opening being in communication with an opening extending between the upper end and the lower end of the mandrel. The apparatus preferably further includes at least an axis extending between the blind opening and the porous π member 'to provide fluid communication between the blind opening and the porous member. In operation, a vacuum is drawn through the opening π of the d, the blind opening and the at least-axis to form a suction on one surface of the porous member .

Preferably, the apparatus further includes a heating element opposite the second surface of the plate such that the porous element is directly exposed to the heating element such that the porous element is unobstructed by the heating element Direct heating. Preferably, the lower end of the mandrel is coupled to a vacuum pump such that the pressure level on one of the surfaces of the porous member is less than the pressure level within the reaction chamber. [Embodiment] FIG. 2 shows an apparatus for growing an epitaxial layer on a wafer. The apparatus includes a deposition chamber 100 including a sidewall 1〇2, and a top flange 1〇4 including one or more openings 106 for introducing reactant chemistries (eg, reactant gases) into the deposition An interior region 108 of one of the chambers 100. The deposition chamber 1 also includes a bottom sealed flange 110. The deposition chamber 1 is made of stainless steel, and the top and bottom flanges 104 and 110 are in sealing engagement with the side walls 102. The reactant gases introduced via the openings 106 in the top flange 104 are generally evenly distributed by one or more showerheads 114. The reactant gases interact with each other within the deposition chamber 100 to form an epitaxial layer on the wafer. After the reactants 100085.doc -15-1293774 gas interact with each other and are deposited on top of the wafer, the waste material is removed via an exhaust opening 116 extending through one of the bottom sealing flanges 110. In a particular embodiment, the reactant exhausts are removed via the exhaust opening 116 using the pump 11 8 . The pressure level within the interior region 108 of the deposition chamber 1 is adjusted by the throttle valve 120. When the epitaxial layers are grown on the wafer, the wafers 122 are positioned within the deposition chamber 100 and over the wafer carrier 124. Each wafer carrier 124 has a top surface 126, a bottom surface 129, and one or more wafer receiving cavities 128 that are adapted to receive one or more wafers 122 therein. Each of the wafer receiving cavities 128 has a diameter greater than or equal to the outer diameter of the wafer 122 stored therein. Wafer carrier 124 also includes a hollow space 130 formed in bottom surface 129 of wafer carrier 124. The hollow space 13〇 may be centrally located on the wafer carrier 124. The wafer carrier 124 is formed from a substantially porous material (e.g., graphite, SiC, molybdenum, or other well known materials commonly used in wafer carriers). The wafer carrier 124 preferably has a porosity of between about 7 and 14%. The wafer carrier 124 includes an outer flange 132 that defines an outer perimeter of the wafer carrier 124. The wafer carrier 124 is adapted to be positioned atop a rotatable base 134 having a top surface 136 and a bottom surface 138 away from the top surface 136. The base 134 also includes a central opening 14 延伸 extending between the top and bottom surfaces 136, 138. The base 134 is coupled to a rotatable mandrel 142 having an upper end 144 disposed within the interior of the deposition chamber 100 and a lower end 146 located outside the deposition chamber. The uppermost end of the mandrel 142 preferably includes a flange portion 148 mounted to a bottom surface 138 of the base 134 100085.doc - 16 - 1293774. The mandrel 142 can be rotated via pulleys 152, 154 and conveyor belt 156 by a motor 15 turns. The mandrel 142 has an elongated opening 158 extending therethrough that is aligned with a central opening 14〇 extending through the base 134. When the crystal carrier 124 is provided on top of the pedestal 134, the hollow space 130 located at the bottom surface ι 29 of the wafer carrier 124 is preferably substantially aligned with the mandrel opening i 58 and the pedestal opening i4 。. When the wafer carrier 124 and the pedestal 134 are rotated, the outer flanges 132 hold the wafer carrier 124 on top of the pedestal 134. The lowermost end of the mandrel 142 is preferably coupled to the pump 118 for aspiration through the mandrel opening 158. The differential pressure controller ι62 adjusts the pressure within the interior region 108 of the deposition chamber ι and the pressure level within the mandrel opening 158, the pedestal opening ι4, and the hollow space 130 such that the pressure level within the hollow space 13〇 It is always smaller than the pressure level in the inner area 1 〇8 of the deposition chamber 1 。. A vacuum seal is provided between or deposited with the mandrel 142 or around the mandrel 142, for example, by using one or more vacuum rotary feedthroughs 160 and 164. The well-known vacuum rotary feed is manufactured by Ferrofluidic, Advanced Fluid Systems, and Rigaku. As mentioned above, the wafer carrier 124 includes a hollow space 130 formed at the bottom surface 129 of the wafer carrier 124. When the pump 118 is activated, a vacuum is created in the mandrel opening 158, the base opening 140, and the hollow space 13A. The wafer carrier includes one or more channels 135 to communicate with the hollow space 130 such that a low pressure or vacuum within the hollow space 130 can extend through the entire area of the substantially porous wafer carrier. Thus, the pressure level at the interface between the wafers 122 and the wafer carrier (i.e., within the chambers 128) is less than the pressure level within the interior region of the reaction chamber 100, 1 〇 8 100085.doc -17-1293774. As used herein, the term "interface of wafer 122 and wafer carrier" means the area of the wafer carrier that is in direct contact with the wafer placed on the carrier. The lower pressure at the interface draws the wafers 122 into the cavity 128, thereby preventing distortion of the peripheral edge of the germanium wafer 122, which occurs in prior art devices as shown in Figure (3). We have been convinced that maintaining the wafers 122 substantially flat during the deposition of reactant gases on the wafers 122 (i.e., preventing such edge distortion) will result in uniform formation across the entire area of the wafers. A semiconductor wafer of an epitaxial layer. Thus, it is possible to use a half of the body formed on the edge of the wafer instead of being discarded as in the prior art. 3 through 5 show a wafer carrier (2) in accordance with a particular preferred embodiment of the present invention. The wafer carrier 224 is preferably made of any material that can withstand the temperature and chemical environment present in a deposition chamber. In a preferred embodiment, the wafer carrier 224 is formed from materials such as turns, tungsten, sets, and crucibles. The wafer carrier includes a plate 225 having a top surface and a bottom surface 228 remote from the top surface 226. _25 is ground to form a continuous opening 23G extending completely through the plate. In the embodiment shown in Figure (1), the plate (2) has four equally spaced openings through the bottom surface 228 adjacent to one of the bottom:: " the mouth includes the surface of the plate 225 The radius of the top of the adjacent one == blue, and the (four) plate is greater than the radius of the bottom ring blue / 3 4 4 top annular flange 2 3 4 -I flange 232. A disc made of a substantial material is positioned in each of the conductive openings 230. A material made of a substantially porous material may be made of a material such as = 100085.doc -18. 1293774 and graphite. The bottom annular flange 232 defines a first well region for sealing the wafer 236. The top annular flange 234 defines a second well region for receiving an annulus 238 that is inserted into the first well of the 5H to secure the porous disc 236 in place. The fixed 238 can be made of any material (e.g., molybdenum or tungsten) that can withstand the temperature and chemical environment of a deposition chamber. The retaining ring 238 is held in place by a securing member (e.g., a screw Μ.). The plate 225 also has a radially extending hollow shaft 242 extending from the outer circumference of the plate 224 toward a central opening 244 of the plate. As will be explained in greater detail below, the radially extending hollow shaft 242 allows vacuum to be drawn through it. A hollow shaft 242 can be formed using a drill. As mentioned above, the plate 225 includes a blind central opening 244 formed in its bottom surface 228. The blind center opening includes an annular flange 246 to define a bottom well 248 adapted to receive a separate machined member 25". The machined member 25 is fixed in the center hole 244 by a fixing member 252 such as a screw. The machined part 25A includes a central hub 252 made of a non-diffusing material (e.g., a ceramic material). In a preferred embodiment J, the 4 centering line $252 is made of graphite. In other preferred embodiments, the mid-hub 252 is made of any material that does not diffuse into the mandrel material, thereby preventing the wafer carrier 224 from adhering to the mandrel. The hollow shafts 242 define openings in the outer circumference of the plate 225. The openings 254 can be closed by a sealing member 256. The sealing element may include any material from which the open end 254 of the hollow shaft 242 forms a hermetic seal. In a particular preferred embodiment, the sealing member 256 may be a fixing member such as a screw that screws into the opening 254. In operation, the central opening 244 of the wafer carrier 224 is placed in alignment with the upper end of a mandrel such that the opening between the middle and the upper end of the shaft is fluidly connected. The round substrate is positioned on the porous disk 2% of the wafer carrier 224. The vacuum is drawn through the mandrel (not shown), and further, through the center: 244, the hollow shaft 242, and the porous disc inserted into the wafer carrier are pumped. Thus, when the layer of wormholes is grown on the wafer substrates, the outer circumferential edges of the wafer substrates 236 are towed against the top surface of the porous disk 236. As described above, the straight space passing through the porous disk 236 prevents the outer edge of the wafer substrate and the wafer generated on the wafer substrate from being twisted, and the distortion may change the curled region of the wafer. Sex. Providing a device that does not have an interposer (e.g., - pedestal) between the wafer carrier and the heating wire also increases heating efficiency. Although the invention is not limited by the specific theory of operation, it is believed that the provision of an object (e.g., - pedestal) between the wafer carrier and the heating wire will result in the wafer growth procedure. It can occur under conditions where the heating wire is at a much lower temperature. In a specific embodiment of the technique, an object such as a susceptor is positioned between the wafer carrier and the heating wire to obtain a temperature of U5 〇〇c on the top surface of the wafer carrier. The heating wire must be heated to a temperature of about 2,500 to 2,600 Å. Mountain - King Aooo C. This temperature generally exceeds the maximum recommended temperature for the heat line and generally causes the heating wire to melt and deform. In the present invention, an object such as a susceptor is not used, by heating the heating wire to only i, _ to 2, coffee. The c degree can reach the temperature of 1,150 ° C required for the wafer carrying 100085.doc -20- 1293774. This is because the preferred embodiment of the present application provides for direct heat transfer between the heating wire and the wafer carrier. Thus, the present invention provides direct heating of the wafer substrate 224 by means of a heating wire placed in a reaction chamber. As used herein, the term "direct heating" means that no object (e.g., a pedestal) is positioned between the wafer carrier and the heating wire. By having the heater wire directly heat the wafer substrate, the wafer substrate can be more efficiently heated and achieve the relatively high temperatures required to grow a particular wafer, unlike the conditions found in prior art devices. The heating wire is melted and/or deformed. The present invention has been described with reference to the specific embodiments thereof, but it is understood that the specific embodiments are intended to illustrate the principles and applications of the invention. It is understood that various modifications may be made to the specific embodiments of the invention and the invention may be practiced without departing from the spirit and scope of the invention as defined by the appended claims. Industrial Applicability The present invention is applicable to growing an epitaxial layer and fabricating a semiconductor device. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1A is a cross-sectional view of a prior art wafer carrier including a wafer mounted on top of the wafer carrier, a pedestal, and a rotator A mandrel and a heating device for heating the base. Figure 1B shows the prior art wafer carrier of Figure 1a with a stray layer grown on top of the wafers. Figure 2 shows a cross-sectional view of a deposition chamber including a wafer carrier, a rotatable base, and a rotatable mandrel. 100085.doc - 21 - 1293774 Figure 3 is a cross-sectional view of a wafer carrier in accordance with a particular preferred embodiment of the present invention. 4 shows a top perspective view of the wafer carrier of FIG. Figure 5 shows a perspective view of one of the wafer carriers of Figure 3. [Main component symbol description] 10 wafer 12 wafer carrier 14 pedestal

16 Rotatable support mandrel 18 Heating assembly 20 Circular receptacle 22 Wafer carrier 12 upper surface 24 Annular flange 26 Ring wall 28 Peripheral edge 100 Deposition chamber 102 Side wall 104 Top flange 106 Opening 108 Inner region 110 Bottom seal Flange 114 showerhead 116 exhaust opening 118 pump 100085.doc -22- 1293774 120 throttle valve 122 wafer 124 wafer carrier 126 wafer carrier 124 top surface 128 wafer receiving cavity 129 wafer carrier 124 bottom Surface 130 Hollow Space 132 External Flange 134 Rotatable Base 135 Channel 136 Rotatable Base 134 Top Surface 138 Rotatable Base 134 Bottom Surface 140 Center Opening/Base Opening 142 Rotatable Mandrel 144 Rotatable Mandrel 142 upper end 146 rotatable mandrel 142 lower end 148 flange portion 150 motor 152 pulley 154 pulley 156 conveyor belt 158 spindle 142 opening 160 vacuum rotary feedthrough 162 differential pressure controller 100085.doc -23- 1293774 164 vacuum rotation Feedthrough 224 Wafer Carrier 225 Plate 226 Plate 225 First Surface 228 Plate 225 Second Surface 230 Opening 232 Bottom Ring A top annular flange 234 Lan

236 Porous Disc 238 Retaining Ring 240 Screw 242 Shaft 244 Center Opening 246 Ring Flange 248 Bottom Well 250 Separately Machined Parts 252 Center Hub 254 Opening 256 Sealing Element 100085.doc -24-

Claims (1)

Ι29$ϋ6668 Patent Application Chinese Patent Application Renewal (May 96) X. Patent Application Range: A device for growing a wafer, comprising: a plate having a first surface and a second a surface; at least one opening extending from the first surface of the plate to the second surface; a porous member disposed in the at least one opening in the plate, wherein the porous member is adapted Supporting one or more wafers; a blind opening extending from the second surface of the plate toward the first surface by at least one axis extending between the blind opening and the porous member to provide a t-shaped opening Fluid communication between the porous members, wherein suction is formed on one surface of the porous member by suction of the vacuum through the blind opening and the at least one shaft; and a heating element, the heating element and the second surface of the plate In contrast, it is known that the 5H porous element is directly exposed to the heating element, thereby performing unobstructed direct heating of the porous element. 2. A device as claimed in claim 1, wherein the porous member has more holes than the plate. 3. The apparatus of claim 1, wherein the porous member has a porosity of about 7 to 14%, wherein the wafer carrier comprises a group consisting of molybdenum, tungsten, and rhenium. One of the materials selected in the group. 5. The device of claim 1, wherein the panel comprises a material selected from the group consisting of molybdenum, tungsten, knobs, and turns. 6. The device of the request, wherein the porous element comprises a group selected from the group consisting of carbon carbide lithograph and stone 100085-960528.doc 1293774% of the month of repair (fishing jl potential page „^— _ ink The device of claim 1, wherein the blind opening is substantially centrally located on the plate and the at least one axis extends outwardly from the blind opening. The device of claim 7, wherein the at least one axis The blind opening extends radially outward. The device of claim 1, wherein the at least one shaft is adapted to draw a vacuum through it to create a suction on a surface of the porous member. The device of claim 1 wherein the at least _ opening comprises a plurality of openings, each of which is provided with one of the porous members 0. The device of claim 1 The further step comprises a hub placed in the blind opening of the board. 12. The device of claim 11, wherein the hub is made of a non-diffusion material f. The device of claim 1 wherein the hub is made of graphite or ceramic. A device for growing a wafer, comprising: a plate having a first surface and a second surface; a plurality of openings extending from the first surface to the second surface of the plate; y a porous An element disposed in each of the openings in the plate, wherein each of the porous members is adapted to support one or more wafers; a blind central opening from the second surface of the plate Extending toward the first --'; a plurality of axes extending outward from the blind center opening, each of which is -100085-960528.doc 1293774 jab^月4修(€)"h axis white with the blind center opening One of the connections ~ ^ < one end of the brother and the plurality of: one of the elements connected to the second end to provide the blind central opening: fluid communication between one of the porous elements, wherein Pumping a vacuum through the blind central opening and the equiaxions to form a suction on the surface of each of the porous & parts, wherein the heating element thermal element is opposite the second surface of the plate Causing the porous element to be directly exposed to the heating element, And the apparatus of claim 14, wherein the plate is open to the first table of the plate: having -[diameter and having on the second surface of the plate a second diameter, and wherein the first diameter is greater than the second diameter. 16. The device of claim 15 wherein the step further comprises a retaining ring of the diameter-opening that can be inserted into the plate to The porous member is fixed in place. The device of claim 16 wherein the fastening ring comprises a material selected from the group consisting of turning and tungsten. The device of claim 14 wherein the isometric Each axis extends around the periphery of an element of the porous elements. 1 9 - a shock for growing a layer of insect crystals on a wafer, comprising: a rotatable mandrel having a An upper end of one of the reaction chambers and an opening extending between the upper end and the lower end of the mandrel; a rotatable wafer carrier fixed to the upper end of the mandrel, the rotatable wafer carrier comprising : a board having a first surface and a second 100085-960528.doc 1293774 at least one opening extending from the first surface of the plate to the second surface; a porous member disposed within the at least one opening in the plate The porous element is adapted to one or more wafers of a branch, the opening of the opening extending from the second surface of the plate toward the first surface, the blind opening and the upper and lower ends of the mandrel The open extension communicates with at least one shaft extending between the blind opening and the porous member to provide fluid communication between the blind opening and the porous member, wherein the blind is passed through the opening of the mandrel An opening and the at least one shaft to draw a vacuum to form a suction on a surface of the porous member; the device advancement includes a heating element opposite the second surface of the plate such that the porous member is directly exposed to the The element is heated to provide a direct addition to the edge porous element that is unimpeded. The device of 2°.=Γ19, further comprising a heating element, the heating eye 2: the second surface of the plate is opposite to the direct force of the porous element = (4) direct 22 · as requested The 19's skirt is extended by a perimeter. 23. The device of claim 19 14% 〇 24. If the device is requested to drink 19. 21, as claimed in claim 1, wherein the porous member has more holes than the plate. Wherein the at least one axis surrounds the porous member, wherein the porous member has a porosity of about 7 wherein the lower end of the mandrel is connected to a "100085-960528.doc 1293774% ν月修修(: a page empty pump So that the pressure level of one surface of the porous element is less than the pressure level in the reaction chamber. 100085-960528.doc 1293, 100085. • 96〇528.dOC I293y^li〇6668 Patent Application Chinese Graphic Replacement Page (May 96) Figure 4 100085-960528.doc -4-