TW575908B - Method for producing semiconductor crystal and semiconductor light-emitting element - Google Patents

Description

575908 V. Description of the Invention (l) [Technical Field of the Invention] The present invention relates to the use of lateral crystal growth and the formation of a crystal by forming a substrate layer composed of a Group III nitride compound semiconductor on a base substrate. Method for manufacturing semiconductor crystal of growth substrate. [Known Technology] As shown in FIG. 5, it is known that a nitride semiconductor such as gallium nitride (GaN) is crystal-grown on a base substrate made of silicon (si) or the like, and then cooled to room temperature. Most dislocations and cracks will occur on the nitride semiconductor layer. [Problems to be Solved by the Invention] In this way, if the growth layer (nitride semiconducting layer) has a large number of words, when a device is fabricated thereon, lattice defects, dislocations, deformations, cracks, etc. will occur in the device. As a result, the cause of the deterioration of the device will be formed. Furthermore, only the dislocations are left in the wrong place and the problem is solved. The solution is to obtain the characteristics. When the growth layer and the crack are the first-hand family of HI, this base includes the so-called search. In the case where the base substrate is removed, and an independent substrate (crystal) is to be served, it is impossible to obtain a large area (more than icffl2) because of high quality = effect. 62. t ί: The purpose is to obtain crack-free and crystallized conductor (crystal growth substrate). Means, function, and effect of the invention] The segment system utilizes the lateral crystalline silicon and < Nitride system :: to: on the base substrate, and the semiconductor independently of the substrate. 3 kg of substrate layer, and: on the base substrate? Manufacturing steps on the ground ’, the protrusions of which have a large number of protrusions

575908 V. Description of the invention (2) Formation steps; set at least a part of the surface of the protrusion as the initial growth surface of the substrate layer to start crystal growth, and crystal growth of the substrate layer until the growth surfaces are connected to each other and at least A crystal growth step until a series of substantially flat surfaces, and a separation step of separating the substrate layer from the base substrate by breaking the protrusions. Among them, the so-called "Group III nitride-based compound semiconductor" generally refers to the "AlxGay Ιη (1κN; 〇 $ 1.00 $ y. 1,0Sx + y) "S 1" constitutes a semiconductor with an arbitrary mixed crystal ratio shown in the general formula. In addition, semiconductors to which p-type or n-type impurities are added are also included in the scope of the "brother-II group gaseous compound semiconductors" in this specification. In addition, at least a part of the above-mentioned group III elements (Al, Ga, In) is substituted with boron (B), thorium (T 1), or the like, or at least a part of nitrogen (n) is substituted with phosphorus (P), Substituted semiconductors, such as arsenic (As), antimony (Sb), bismuth (Bi), etc., are also included in the category of "m-nitride-based compound conductors" in this specification. Furthermore, the aforementioned P-type impurities For example, magnesium (Mg), calcium (Ca), etc. may be added. In addition, the η-type impurity system may be added for example, silicon (Si), thallium selenium (Se), tellurium (Te), or germanium (Ge). Etc. In addition, 'these impurities can be added at the same time as prime type II (P-type and η-type). Above Wujing' can also be added at the same time, such as illustrated in Figure 1, In the case of Tiancheng County, on the base substrate with a canine starting portion, the substrate layer (semiconductor ~ crystal) made of a compound consisting of a compound of a mouse compound is grown long. Layer "" adjustment of body and knot conditions, etc., can be formed in the <B septum ,, and the daily growth of the text "between the dog's rise (the side of the protrusion),

9ll22l6.Ptd Page 6 575908 V. Description of the invention (3) Big: t: t is empty. Therefore, if the thickness of the substrate layer is sufficient, the middle stress will be 2 :: Γ Γ. The internal or external stress will easily be sheared by 2 2 j. As a result, the stress is particularly important for the protrusion M. How to find, when this stress increases, the protruding part will break. So: =: force? Then, you can easily combine the base substrate and the substrate layer in the second base i! The larger the formation, the greater the 'stress (shear stress)'. 板 The plate :: It is known that by forming the protrusions as described above, the contact sites between the widely needed semiconductor crystal layers are made by the two: It is more difficult to generate G: ϊ: and due to the difference between the crystal 袼 constants of the two. ί ΐ The difference in the lattice constant between the substrate and the substrate layer is referred to as) // When the P is shown in the crystalline growth substrate layer (required semiconductor junction), it suppresses the action on the growing substrate and reduces misalignment or turtles. The density of cracks. ] Not only stress' In addition, when the base substrate is separated (peeled off) from the substrate layer, part of the substrate layer remains on the substrate, or part of the base substrate remains on the substrate layer (for example: protrusions Broken wreckage). In other words, the above-mentioned separation step is not based on the premise of the complete separation of each material that does not have a part of these materials (a necessary condition). Furthermore, the second means for solving the above-mentioned problems is that in the first means, the substrate layer and the base substrate are cooled or heated to generate a stress derived from a difference in thermal expansion coefficient between the layer and the base substrate. And use spear ^

575908 V. Description of the invention (4) This stress implements the fracture of the protrusions. According to this method, it can be lightly produced. In addition, the third method is to use the lateral crystal 2 stress. Formed by group m nitrides: long-acting, semiconductor substrate on the base substrate to obtain crystals-Niu Er, the substrate layer composed of conductors, ~ clothing &amp; steps, i. The protrusions are made; at least a part of the surface of the base, the step of forming the protrusion; the protrusions are initially grown, and the substrate is pushed to Γ1 as the substrate layer begins to crystallize, and at least ^ A = ,,, ° crystal growth, until this growth surface is divided into steps; wherein, here the crystal growth of the ox kebab is approximately flat, the raw material of the compound semiconductor for the crystal growth of the second = medium, by adjusting the nitride The difference between the basal substrate protrusions and the semiconductor crystal growth rate of the base substrate protrusions at least one part of the interval between the three valleys ("ba"), the difference (ba) between the second group nitride formation rate b and the protrusions According to this method, the crystal growth at the top of the head is approximately maximum. The increase of the opposite sex and the growth rate of the crystal near the top of the sex are relatively strong, and dominate the crystal growth near the top of the head from the above-mentioned exposed area. As a result, waiting for the crystal growth of the substrate layer from the protrusion portion, the growth toward the EL0 will become significant, and if the substrate between the substrate and the substrate layer is forested, and "the crystal structure of the substrate layer is stable with the substrate layer" Bad stress. " So ‘base phenomenon. It is more difficult to produce dislocations and cracks on the lamellae layer. The lateral ridges of the substrate layer may be relatively large on the side of the protrusion (if l ^ (LE0) becomes significant, such as the gap between the dogs). Hollow love 91102216.ptd V. Description of the invention (5) Case 0 The surrounding part near the wall is more than eight months ^ μ '. Generally, although the side surface of the outer edge of the base substrate is also based on "knot === appropriate, you can: : Difference: (== Go again, the philosopher makes a roughly large value. In this step, the crystal growth step q 'of the second means is used to supply the raw material of the compound semiconductor between the substrate substrate and the substrate. At least a part of the Group III nitrogen in the region is exposed to the top of the head of the protrusion; the semiconductor crystal growth rate a 'is approximately the maximum. The S-score (ba) between the growth degree b is controlled to be In this case, as described above, the stress derived from the constant difference when the substrate layer crystal grows on the substrate layer can be relieved. The lattice f between the substrate and the substrate layer is harder to produce a misalignment. The crystal structure is stable, and the two protrusions (sides of the protrusions) are the same. In this case, the effect and effect are “significant.” In the case of lateral growth, the shearing can be easily used. In the above separation step, the effect and effect can be used to separate the base substrate and the substrate layer. This effect is The larger the gap between Tian's protrusions (the sides of the protrusions): 575908 V. Description of the Invention (6) The more significant, the fifth means is the third or fourth means to supply the above raw materials The amount q is set to 1 // mol / min or more and 100 or less. It is preferable that the raw material supply amount q is set to 5 # m〇1 / min or more and 90 / zmol / min or less. A better range value Although it depends on various conditions such as the size and shape of the formed protrusions, the base substrate specifications such as the placement interval, the type of raw material to be supplied = the direction of the flow of the supply, and the crystal growth method, it is about 10 ~ 80 # m〇1 / min. It is more ideal. The value of this range is' if the intersection between m and the above-mentioned difference (b_a) is controlled to the approximate maximum value, so it is difficult to form a space between the four dogs (side of the protrusion), and the lattice The constant difference derived from the surname to "... in this 11 sum, and dislocation However, it is easy to guide: the second and third forces are more difficult to mitigate, so it is best not to. The early crystallinity of the substrate layer is poor due to the poor crystallinity (shear stress), even if the base substrate and the substrate are increased by a knife. Away, the side of the right protruding part is allowed to ... If it is difficult, the stress will be harder to concentrate on the small part of the protruding part ', 2 and 1 s, so it is better not to. "On the other hand, it is less likely to cause protrusions." If the amount of raw material supply q is too small for a long time, it will not be conducive to production, so it is best not to say "the growth time will be too long. The sixth means is the first to the above." The substrate material is made of silicon (Si) or silicon carbide (Si). In addition, the substrate can be used for other substrate materials: InP, GaP, MgG, ZnQ, MgA &amp; ^ NUGaAs, 204 , In addition, sapphire,

Page 10 575908 V. Description of the invention (7) Spinel, oxide, gallium oxide clock (L i G a 〇2), molybdenum sulfide (μ 0 s), etc. Among them, when the shear stress derived from the difference in thermal expansion coefficient is used to separate the base substrate and the substrate layer, it is best to choose a combination that does not make the difference in the expansion coefficient between the two materials smaller. Furthermore, the base substrate is preferably a relatively broken material. &amp; Comment on the early morning and no more, the seventh means is in any of the first to sixth mentioned above-using Sl (111), and in the valley area between the raised part and the base of the dog, Unexposed protrusions are formed. According to this method, since the valley growth rate a can be controlled to be small, the above-mentioned difference (b ~ i) can be substantially maximized. The crystallinity is stable. Also, the crystallinity is controlled, and The eight means is a step of forming a buffer layer composed of protrusions A ^ xfai-xN (0 &lt; X g 1) "which is at least less than the protrusion surface after the steps of forming the first to seventh parts. 'In addition to this buffer layer, the intermediate layer period such as: MN or A1GaN) can also be used, and the layers are roughly laminated with other layers, or a multilayer structure is formed. The stacking of the buffer layer (or the middle layer) can increase the crystallinity by the constant force acting on the substrate layer (growth layer). Xinli Temple ’is the same as the conventional method = ΐ, and the ninth means is in the eighth means described above, and will reduce the length of the protrusions to less than or equal to the longitudinal direction. Moreover, the absolute thickness of the punching layer is set to be about 0.000, 乂, and below. Pu Fengze buffer layer thickness

911〇2216 Ptd Page 11 575908 V. Description of the invention (8) By this means, only the required crystalline layer (such as the G a N layer) formed on the buffer layer can be grown laterally. That is, by using the master to increase the number of crystal layers formed on the buffer layer, 66 ", T 丨 stress derived from the lattice constant" during crystal growth, and can effectively reduce the misplaced goods # = A1N of buffer layer and so on. 'Easier ;: on the entire surface of the base substrate chromium exit surface, and two days before the original formation. If the above-mentioned means are easier to grow horizontally, it is possible to more surely form a larger "void" on the side of the protrusion. Furthermore, by this means, when the substrate layer is separated from the base substrate, the crystal layer (the required layer on the three layers) will be exposed in a wide range on the back of the substrate layer (one side with the base substrate). Therefore, when the electrodes are formed on the back of the buffer, the electrical impedance can be easily controlled. Field soil layer. Although the thickness of the buffer layer is about ^ right as described above, it is a more appropriate range, but it is particularly preferably above. If this thickness is too thick, the cavity will easily become smaller: = lower layer. Especially in the case of; near stool = ;: rr's buffer = part of the membrane) ... sex will also be accommodated. Furthermore, the tenth means of the present invention is in the step of crystal growth, and it is convenient to use any means ,,,, The substrate layer that grows day by day (the degree of the m group is preferably about 5. _ or more. This thick household: = compound semiconductor) The thicker the thickness is, the more the substrate layer is pulled.

91102216.ptd Page 12 575908 V. Description of the invention (9) The tensile stress will be alleviated, and the misalignment or cracking of the substrate layer can be reduced to produce “intensified substrate layer” and the above shear stress can be easily removed. In the above-mentioned protruding part. Shan again, the tenth means is the growth step in any one of the means from the first to the tenth, and will be crystallized in the middle of = growth method, Ό ς, 法 yang growth method, change To increase the crystal growth capacity of the crystal with a faster crystal growth rate: ί ΐ ί until the growth surface forms a series of approximately flat shapes, use (L knife (b — a) to maximize the crystal growth, and remove (eg: M0VPE method) Then, an effective method for easily forming the thickness by 1 (such as the _ method) is adopted, so that semiconductor crystals of good yttrium quality can be crystallized in a short period of time. The means is in the formation step of the Bu Department. You can use any of the means of t 十 to place the means to form the above-mentioned protrusions: roughly find the time ... at regular intervals to match the 'horizontal growth of the growth of the growth of the crystalline quality. It will be more difficult to give birth above 4 ' Using the substrate layer to completely cover =: The unevenness between the valleys of the protrusions causes local unevenness, so for example: d '' because it is difficult to produce; crystallization into a slower crystallization method, the crystallization is faster in the middle The master of the growth method is more crystalline and the growth rate is determined intently. At this time, Γ 0 "can be easily correct, early, or again. According to this method, etc., the above cut #: D will form the above holes. Approximately uniform q-shear stress is distributed approximately equally on each protrusion, 9ll022l6.ptd Page 13 575908

Therefore, breakage of all the protrusions does not cause uneven separation of the base substrate and the substrate layer. And it can be surely implemented that the thirteenth means is to form protrusions on the lattice points of the triangular lattice in roughly equal to the number of steps in the tenth second-hand $ &amp; α step above. . Based on the second method, hunting, this method can be implemented more consistently than the twelfth method mentioned above, and the number of misplacements can be reduced reliably. Eight gall, true hexagon, approximately round, or quadrangular. By this means, since the compound semiconductors have approximately the same horizontal level of the protrusions, the triangles are easy to be appropriate. In addition, the ease of formation is a relative advantage. In order to easily limit the length (thickness) of the crystals that can form crystals at various locations, the number of dislocations can be suppressed. Due to the semiconductor crystal shape or the quadrangle shape, the current general etching process is used to integrate the direction of the m-group nitride axis, or because it can be a regular hexagon or a positive crystalline structure in any horizontal direction, so in the most technical point of view, In the current state of technological standards, the '15th means is the protrusion forming step of the 14th means, and the protrusion arrangement interval (arrangement period) is set to 0 · 1 "m or more and 1 0 // m or less. Although it depends on the implementation conditions of crystal growth, it is best to set the arrangement interval of the protrusions at about 0.5 to 8 / zm. The arrangement interval refers to the center points of the protrusions that are close to each other. By this means, the substrate layer can be used to cover the upper part of the valley of the protrusion, the same as

91102216.ptd Page 14 χ59〇8 丨-Explanation of the invention (11) A cavity can be formed between the protrusions. : If this value is too small, the effect of EL0 is hardly obtained, and it is different. In addition, if the formed cavity is too small ~ b will exceed the required thickness by day, the protrusion will be 4 = the thickness of the layer is not over, if this value is too large, the upper part of the valley of the dog's rising part cannot be determined. It is not possible to obtain crystallinity: cover (substrate layer). The crystallizing method of 仏, 二 = 2. If the value of 过 is too large, the exposed surface of the valley will be too wide, and it will almost become profitable. In addition, when the thickness of the substrate layer does not exceed 50 μs, the protrusions are less likely to break. In the case where the degree is equal to or higher, the sixteenth means is under the protrusions of the fifteenth means 'set the longitudinal height of the protrusions to be more than 0.5 centimeters, and 20% is a speech that is too low in height.' Just like in the case of no protrusions, the helmet method "ELO" is almost used, and the above mentioned cavities cannot be formed if the method is used.… If the height of the ridges that pass through the low protrusions is too high, the protrusions themselves are difficult to form. It will take a considerable amount of time for the substrate to be consumed. 'I The base substrate material is more than C, so it is best not to use it. In addition, if the fracture protrusion force is too high, it will be dispersed in the longitudinal direction of the protrusion χ 'And the traffic accident is truly true, the seventeenth means is the step of forming the protrusion of the sixteenth means 91102216.ptd page 15 575908 5. In the description of the invention (12) step' will be raised &amp; ^ And the k-direction thickness, width, or diameter of 10 / 卩 is set to 0.1 so that the protrusion Γ is 22; 7, the crystal grows, and the solid is right. The shot size or diameter is set to 0.5 to 5 / zm. Zuo Ruo this rough through the stress on ^ 日 ώΛι &amp; long layer), with the lattice constant And acting on the substrate layer (into the wrong number of bits. The reverse will become larger, and it is easier to increase the difficulty of the substrate layer, or if the protrusions are too delicate, the protrusions themselves will be better formed. The growth rate b will be slow, so most of all, gp is convenient to use when the protrusion is broken, etc.) and the protrusion is broken, it is easy to produce the effective method. If the width, or diameter is too large, because It is best not to allow the rip _ cracked part. The magnitude of the influence is not bad, and the stress acting on the substrate layer (growth layer) depends on the lateral thickness (length) of the protruding part that exists in the protruding part. If so, as mentioned above, ρ ί ί ί. Therefore, if the setting range is not suitable, it is easy to increase the stress effect of the difference in the σ coefficient of the substrate sound, and more importantly, the sudden :: number, so the most It ’s okay. Because of the above settings, the horizontal thickness, width, or diameter near the part, the appropriate value or range of the surface, bottom, or level (the upper part of the protrusion), especially the shape of the cross section of the external phase, At least partially sealed The shape of the island (island, bottom, or water, protruding and closed shape is preferred. Especially the first-class shape is better. 7. The shape of the surface is approximately circular or approximately regular polygonal direction. By setting ib, the above-mentioned optimum value or appropriate range can be realized with respect to any level.

Page 16 575908

V. Description of the invention (13) B means again that the eighteenth means are in any of the seventeenth means mentioned above :: wide-cut processing, electron beam irradiation processing, Tianshe Temple ancestor processing, chemical treatment, or Cutting or cutting can be reduced by causing deterioration or changes in the crystallinity or molecular structure of at least one of the _ 5 domains in the valley portion of the base substrate protrusion; Crystal growth rate of the group m nitride-based compound semiconductor in the region By this means, the difference (b-a) of the crystal growth rate can be made larger. Therefore, "Yangtaiban if you follow this method" J Gu because the growth rate of the knot near the top of the dog's head is relatively large, so by the effect as described above, the effect of the substrate layer crystal growth can be eased The stress derived from the difference in lattice constant between the substrate and the substrate layer on the substrate layer ", and it is more difficult to cause dislocations and cracks on the substrate layer. Furthermore, in the nineteenth means, in any of the above-mentioned separation steps, the substrate consisting of the base substrate and the substrate layer is left in the reaction chamber of the growth device, and ammonia (NH3) is supplied at a substantially constant flow When the air flow is in the reaction chamber, it is cooled to about normal temperature at a cooling rate of about "-10 (rc / nlln-0.5t: / min". For example, by this method, the substrate layer can be maintained with high quality. It is crystalline, and the above-mentioned separation step can be carried out with certainty. Furthermore, the tenth means is at least after any of the above-mentioned separation steps. Debris removal step to remove by physical processing. According to this method, when the substrate layer is on the backside (the surface on which the base substrate is peeled off)

91102216.ptd Page 17 575908 V. Description of the invention (14) When electrodes such as semiconductor light-emitting elements are formed on the electrode, it is possible to suppress the occurrence of current unevenness or electrical impedance near the interface between the electrode and the substrate, thereby achieving the driving voltage. , Low, or increase luminous intensity. Furthermore, by removing the broken debris of the protrusions, when the reflectors such as electricity, light emitting elements, etc., will be reduced on the mirror surface. Absorption and scattering will increase the reflectance, so the luminous intensity can be improved. = "For example, when using physical processing such as grinding to implement this residual removal step, when the situation occurs", because the buffer z can be removed to the back of the substrate layer or the flatness of the back of the substrate layer can be improved, it can be suppressed The current does not affect electrical impedance, or reduces light absorption and scattering near the mirror surface, and strengthens the above-mentioned effects. Furthermore, the twenty-first means is based on a group m nitride compound semiconducting light-emitting element +, and is provided with: the above-mentioned first to twentieth Zhongfeng Feng Di-body ϊ: mf crystal manufacturing method 'The resulting semiconductor crystal is used as an &amp; crystal growth substrate. In this case, α, according to this method, it is possible to easily manufacture the m-group nitride compound semiconductor 5 especially by using high crystallinity. In addition, the twenty-second means is a method for manufacturing a semiconductor crystal using the above-mentioned first to second methods, and the 52-crystal produced is used as the crystal growth of the crystal growth substrate to manufacture the first method. A compound semiconductor light-emitting element is realized. According to this method, by using this method, m group nitride compound semiconductor light-emitting materials can be easily manufactured by using high-quality crystallinity and relatively high internal stress.

91102216.ptd Page 18 575908 V. Description of the Invention (15) Elements. With the help of the hand description, 0 can be solved. [Inventive embodiments] The following description of the present invention is not limited to the following embodiments.焉 is also listed for explanation. However, the present invention exemplifies the outline of the manufacturing sequence in which the present invention is implemented.蛉 脰 Crystal (crystal growth substrate) [1] Protrusion formation steps As shown in Figure 2,

On the Si (m) surface, the photolithography is used to treat the dry =: = $ m of the base substrate M1 and a substantially cylindrical L ′ with a height of about 1 // m, and the diameters are formed at intervals of 1 #. The configuration pattern is based on a large: 10a, a two-dimensional triangular lattice based on a distribution of about 2 _, which is approximately the center of the cylindrical bottom surface of the regular triangle, and the shape and Q pull sub-points are arranged at the protrusions. 〇la The thickness of 101 is about 20 0 _. Has been 10 la. Among them, the base substrate [2] is a long-step product 2: == :, as shown in FIG. 4, using the organometallic compound two-phase state) are connected to each other and grow into a series of approximately flat (hvpe w growth steps) 'Then' follow the hydride vapor phase growth method mp κ, Shi Zhiding until the base plate (crystal layer) grows to about 2 0 0 // m and the degree of growth steps. F outer λ, in this crystal growth step It uses ammonia (NH3), carrier gas, trimethylgallium (Ga (CH3) 3, hereinafter referred to as "TM (ί"), and trimethyl 575908.) V. Description of the invention (16) Keming (A1 (CH3) 3 ' (Hereinafter referred to as "TMA"). (A) First, the base substrate 101 (FIG. 2) on which the protrusions 101a are provided is cleaned by organic cleaning and acid treatment, and then mounted on a crystal for growth. On the crystal seat in the reaction chamber of the device, and under normal pressure, while &amp; flowing into the reaction chamber, the base substrate 101 was dried at a temperature of 丨 (pc). (B) Next, The base substrate ι〇ΐΛ is supplied with H2, NH3, TMG, and TMA according to the MovpE method to form an AiGaN buffer layer (substrate The first layer) 102a. The crystal growth temperature of this AlGaN buffer layer 102a is about 1100 and the thickness is about 0.3 // m (Fig. 3). (C) Here the AiGaN buffer layer (the first layer of the substrate layer) 1023 In the above, supply &amp;, NI, and TMG, so that a part of the second layer of the substrate layer (that is, the GaN layer 102b with a thickness of about 5 // m) is grown at a growth temperature; [07 5. By this Step, as shown in FIG. 4, a part of the second layer of the substrate layer (GaN layer 丨 〇2b) will grow laterally, and a large cavity will be formed in the valley (ie, the side of the protrusion 丨 〇 丨 a). In addition, the TMG supply rate at this time is about 40 vmoi / min, and the crystal growth rate of the second substrate layer (GaN layer 102b) is about}. (D) Then, according to the hydride vapor phase growth method (HVpE Method) to make the above GaN layer (substrate layer second layer) 102b more crystalline and grow to 200 // m. The crystal growth rate of the GaN layer 102b of this HVPE method is about 45 // m / Hr. [3] Separation step Step (a) After the above crystal growth step, ammonia (NH3) gas is flowed into the reaction chamber of the crystal growth device, and the base substrate 101 and (from A1GaN slow

575908 V. Description of the invention (17) The substrate layer 102 composed of the punched layer 102a and the GaN layer 102b is cooled to approximately normal temperature. The cooling rate at this time is about "-50 ° C / min ~ _5 ° C / min". (b) Then, after taking it out of the reaction chamber of the crystal growth apparatus, a GaN crystal peeled from the base substrate 101 was obtained. However, in this crystal system, a small part of the A1 G a N buffer layer 10 2 a remains on the back surface of the Ga N layer 1 02 b, and the debris is fractured from the protruding portion 101 a. [4] Straight crack debris removal step After the above separation step, an AlGaN buffer layer composed of s 丨 remaining on the back surface of the GaN crystal is formed by an etching treatment using a mixed solution of nitric acid added to hydrofluoric acid. The fracture remains of 2a were removed. By the above manufacturing method, a high-quality GaN crystal (GaN layer 102b) having a thickness of about 200 and excellent crystallinity can be obtained, that is, a desired semiconductor substrate independently obtained from the base substrate 101 can be obtained. Furthermore, in the above-mentioned embodiment, as shown in FIG. 2, although the projection or valley portion of the base substrate is composed of a vertical plane and a horizontal plane, it may be formed into an arbitrary inclined surface or curved surface. Therefore, the cross-sectional shape of the valley formed on the base substrate illustrated in FIG. 2 (c) may have a shape such as a generally U-shape or a substantially V-shape in addition to a generally rectangular concave shape, and generally such The shape, size, interval, arrangement, orientation, etc. can be arbitrary. [Explanation of element number] 101 Base substrate (Si substrate) 1 0 1 a Projection 102 Substrate layer (nitride semiconductor layer)

575908

91102216.ptd Page 22 575908 Brief description of the drawings Fig. 1 is a schematic perspective view of a base substrate with protrusions and a portion of a semiconductor crystal grown thereon, which illustrates the effect of the present invention. [2 System phase βπηρ Real solid icrmn-fragment mode perspective view (a), top view (b), and cross-sectional view (c). FIG. 3 is a schematic perspective view (a), a top view (b), and a cross-sectional view (c) of a base substrate 101 on which a first layer of the substrate layer (a 1G a N buffer layer) 1 02 is formed. FIG. 4 is a schematic perspective view (a), a top view (b), and a cross-sectional view (c) of the base substrate 101 of the rich-layer substrate layer ι02 (layers 102a and 102b). FIG. 5 is a schematic cross-sectional view of a conventional semiconductor crystal on a base substrate.

91102216.ptd Page 23

Claims (1)

575908, patent application scope 1 · A method for manufacturing semiconductor crystals "uses lateral crystal growth" to form a substrate layer composed of a group in nitride-based compound semiconductor on a base substrate, and obtain an independent substrate from the above-mentioned base substrate The method for semiconductor crystallization includes: a protrusion forming step for forming a plurality of protrusions on the base substrate; and setting at least a part of the surface of the protrusions as an initial growth surface of the substrate layer to start crystal growth. And crystal growth of the substrate layer 'until the growth surfaces are connected to each other and grow at least to a series of substantially flat surfaces; and the substrate layer and the base substrate are separated by breaking the protrusions. Separation step. 2 · The method for manufacturing a semiconductor crystal according to item 1 of the scope of patent application, wherein the substrate layer and the base substrate are cooled or heated to generate a stress derived from a difference in thermal expansion coefficient between the substrate layer and the base substrate. 'And use this stress to break the protrusions. ~ 3 · A method for manufacturing a semiconductor crystal, which uses a lateral crystal growth effect to form a substrate layer composed of a group III nitride compound semiconductor on a base substrate to obtain a semiconductor crystal, which is characterized by the following: : Υ On the base substrate, a protrusion forming step that forms a large number of protrusions sets at least a part of the surface of the protrusions as the initial growth surface where the US plate layer starts crystal growth, and the substrate layer is advanced. Shi Yuecheng 575908 VI. A crystal growth step with a long patent application range until the growth planes are connected to each other and at least grow to a flat surface; wherein, in the above crystal growth step, the raw material supply amount q of the compound semiconductor is adjusted by adjusting: Do not sacrifice the first group m nitride-based compound semiconductor 1 in the exposed area of the protrusion #interval of the base substrate ^ with a speed β of 6 纴 V, V, 突起, 日, 日, 日, 日, 日, 日, 日, 日, 日, 日, 日, 日, 日, 日, 日, 日, 日, 日, 日, 日, dai, 日, and 口 at the exposed area of the protrusion #part of the base substrate, and the group m nitride-based compound semiconductor 1 at a speed β, and the top part of the protrusion part 6 纴, V, 口, 口 日 日The difference (b-a) between the crystal growth rates b of growth π ^ i = is controlled to be approximately the maximum. 4 · As in the semi-conductor of item 1 of the scope of patent application, in the above-mentioned crystal growth step :: ,,, °, said manufacturing method, which. ^ Λ, ^ ^ AA I ^ the reason for adjusting the above Π [ The amount of raw material supply of the group nitride halogenated a-half v-body q passes the upper command of the base substrate 4 ^ Ψ ^ ^ ^ m. ^ I Λ ΛΛ compound-based compound semiconductor crystal growth of at least a part of The speed λ '' Ϊ 2 ΐ ^ The difference (ba) 'between the crystal growth speed at the top of the head is controlled to be approximately the maximum. 5. The method for manufacturing a semiconductor crystal according to item 3 of the scope of patent application, wherein the above-mentioned raw material supply amount Q is set to 1 μmol / min or more and 100 // mol / min or less. 6 · t t: The method for manufacturing a semiconductor crystal according to item 1 of the patent, wherein the substrate material of the bottom substrate is silicon (S i) or silicon carbide (S i C). • For example, the method for manufacturing a semiconductor crystal according to item 丨 of the patent scope, wherein the above-mentioned soil base substrate material is S i (1 11), and in the step of forming the large portion, the protrusion on the base substrate is used. A protruding portion is formed in the joint portion region without exposing the S i (1 11) plane. Page 25 575908 6. Application for Patent Scope 8. The method for manufacturing a semiconductor crystal according to item 1 of the patent application scope, wherein after the above-mentioned protrusion forming step, it is provided with: at least on the surface of the protrusion, an AlJahNCO &lt; x $ 1) ”. 9. The method for manufacturing a semiconductor crystal according to item 8 of the patent application, wherein the thickness of the buffer layer is set to be less than the longitudinal height of the protrusion. 10. The method for manufacturing a semiconductor crystal according to item 1 of the scope of the patent application, wherein in the above-mentioned crystal growth step, the thickness of the substrate layer is set to 5 0 // m or more. 1 1. The method for manufacturing a semiconductor crystal according to item 1 of the scope of patent application, wherein the crystal growth method is changed from a crystal growth method with a slower length to a crystal growth rate in the above-mentioned crystal growth step. Faster crystal growth method. 1 2. The method for manufacturing a semiconductor crystal according to item 1 of the scope of patent application, wherein in the step of forming the protrusions, the protrusions are formed by arranging the protrusions at approximately regular intervals or at a constant period. 1 3. The method for manufacturing a semiconductor crystal according to item 12 of the scope of patent application, wherein, in the step of forming the protrusions, the lattice points of the two-dimensional triangular lattice based on a substantially regular triangle with a side of 0.1 / zm or more are used. The protrusions are formed thereon. 14 · The method for manufacturing a semiconductor crystal according to item 1 of the patent application scope, wherein in the step of forming the protrusion, the horizontal cross-sectional shape of the protrusion is formed into a substantially regular triangle, a substantially regular hexagon, a substantially circular shape, or The quadrangle. 91102216.ptd Page 26 575908 6. Application for patent scope 1 5. The method for manufacturing a semiconductor crystal according to item 1 of the patent application scope, wherein in the above-mentioned protrusion forming step, the above-mentioned protrusion arrangement interval is set to 0.1 // m or more and 10 // m or less. 1 6. The method for manufacturing a semiconductor crystal according to item 1 of the scope of patent application, wherein in the step of forming the protrusions, the longitudinal height of the protrusions is set to 0.5 // m or more and 20 // m or less. 1 7. The method for manufacturing a semiconductor crystal according to item 1 of the scope of patent application, wherein in the above-mentioned protrusion forming step, the lateral thickness, width, or diameter of the protrusion is set to 0.1 // m or more, and 10 // m or less. 1 8. The method for manufacturing a semiconductor crystal according to item 1 of the scope of patent application, wherein before the above crystal growth step, various etching treatments, electron beam irradiation treatments, optical treatments such as laser, chemical treatments, or cutting or grinding are used. Physical treatment causes deterioration or change in crystallinity or molecular structure of the exposed area of at least a part of the valley portion of the base substrate protrusion, thereby reducing the crystal growth rate of the group III nitride compound semiconductor in the exposed area. a. 1 9. The method for manufacturing a semiconductor crystal according to item 1 of the scope of patent application, wherein, in the separating step, a substrate composed of the base substrate and the substrate layer is left in a reaction chamber of a growth apparatus, and The ammonia (NH3) gas was passed through the reaction chamber at a substantially constant flow rate, and the substrate was cooled to approximately normal temperature at a cooling rate of approximately "-100 ° C / min to -0.5 ° C / min". 20. The method for manufacturing a semiconductor crystal according to item 1 of the scope of the patent application, wherein at least after the above separation step, a method for leaving the residue on the above base is provided. 91102216.ptd Page 27