Source: http://www.google.com/patents/US7871843?dq=U.S.+Patent+
Timestamp: 2016-09-26 23:30:55
Document Index: 26956176

Matched Legal Cases: ['Application No. 2', 'Application No. 02802023', 'Application No. 200580040008', 'Application No. 200580040008', 'Application No. 02802023', 'Application No. 02762734', 'Application No. 03778841', 'Application No. 03733682', 'Application No. 02', 'Application No. 2003', 'Application No. 2004', 'Application No. 2004', 'Application No. 2003', 'Application No. 2004', 'Application No. 2003', 'Application No. 2003', 'Application No. 2004', 'Application No. 2004', 'Application No. 2004', 'art 2', 'art 2', 'Application No. 2004', 'Application No. 2004', 'Application No. 2003', 'application No. 2003', 'Application No. 02802023', 'application No. 2003', 'Application No. 02821230', 'Application No. 2004', 'Application No. 02']

Patent US7871843 - Method of preparing light emitting device - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inPatentsThe object of this invention is to provide a high-output type nitride light emitting device. The nitride light emitting device comprises an n-type nitride semiconductor layer, a p-type nitride semiconductor layer and an active layer therebetween, wherein the light emitting device comprises a gallium-containing...http://www.google.com/patents/US7871843?utm_source=gb-gplus-sharePatent US7871843 - Method of preparing light emitting deviceAdvanced Patent SearchTry the new Google Patents, with machine-classified Google Scholar results, and Japanese and South Korean patents.Publication numberUS7871843 B2Publication typeGrantApplication numberUS 12/109,075Publication dateJan 18, 2011Filing dateApr 24, 2008Priority dateMay 17, 2002Fee statusPaidAlso published asUS20060138431, US20090315012Publication number109075, 12109075, US 7871843 B2, US 7871843B2, US-B2-7871843, US7871843 B2, US7871843B2InventorsRobert Dwilinski, Roman Doradzinski, Jerzy Garczynski, Leszek Sierzputowski, Yasuo KanbaraOriginal AssigneeAmmono. Sp. z o.o., Nichia CorporationExport CitationBiBTeX, EndNote, RefManPatent Citations (189), Non-Patent Citations (121), Classifications (22), Legal Events (1) External Links: USPTO, USPTO Assignment, EspacenetMethod of preparing light emitting device
US 7871843 B2Abstract
1. A method of preparing a light emitting device structure having an n-type nitride semiconductor layer, an active layer and a p-type nitride semiconductor layer in order on a substrate and comprising an AlxGa1-xN (0≦x≦1) layer included in said n-type nitride semiconductor layer or said p-type nitride semiconductor layer, said AlxGa1-xN (0≦x≦1) layer being obtained by a supercritical ammono process compressing the steps of:
(i) providing a feedstock containing at least one of gallium and aluminum, a mineralizer containing alkali metal or alkali metal complex, a wafer including at least a part of said n-type nitride semiconductor layer or said p-type nitride semiconductor layer formed on the surface thereof and ammonia-containing solvent containing ammonia or derivative thereof in a reactor;
(ii) bringing said ammonia containing solvent in super-critical state;
(iii) maintaining a dissolution zone in said reactor, where said feedstock is disposed, at a dissolution temperature thereby dissolving at least a part of said feedstock into said ammonia-containing solvent in supercritical state: and
(iv) maintaining a crystallization zone in said reactor, where said wafer is disposed, at a crystallization temperature higher than said dissolution temperature thereby crystallizing said AlxGa1-xN (0≦x≦1) layer on said wafer from said supercritical state ammonia solvent including dissolved at least a part of said feedstock.
2. The method of preparing a light emitting device structure according to claim 1, wherein before crystallizing said AlxGa1-xN (0≦x≦1) layer, said wafer is covered with a mask except the region where said AlxGa1-xN (0≦x≦1) is crystallized.
3. The method of preparing a light emitting device structure according to claim 1, wherein said mineralizer is Li or a complex thereof.
4. The method of preparing a light emitting device structure according to claim 1, wherein said AlxGa1-xN (0≦x≦1) layer is formed on a ternary or quaternary nitride layer formed in said n-type nitride semiconductor layer or said p-type nitride semiconductor layer.
5. The method of preparing a light emitting device structure according to claim 1, wherein said AlxGa1-xN (0≦x≦1) layer consists of GaN.
6. The method of preparing a light emitting device structure according to claim 1, wherein said AlxGa1-xN (0≦x≦1) layer is formed in said n-type nitride semiconductor layer.
7. The method of preparing a light emitting device structure according to claim 1, wherein said active layer consists of an In-containing nitride semiconductor,
wherein said AlxGa1-xN (0≦x≦1) layer is formed in said p-type nitride semiconductor layer.
8. The method of preparing a light emitting device structure according to claim 1, wherein said AlxGa1-xN (0≦x≦1) layer has dislocation density of 104/cm2 or less.
9. The method of preparing a light emitting device structure according to claim 1, wherein said substrate is a heterogeneous substrate different from a nitride semiconductor.
10. The method of preparing a light emitting device structure according to claim 1, wherein said crystallization temperature is 600� C. or less.
11. The method of preparing a light emitting device structure according to claim 1, wherein said dissolution zone is located above said crystallization zone.
12. The method of preparing a light emitting device structure according to claim 1, wherein said substrate is a gallium-containing nitride bulk single crystal,
wherein said n-type nitride semiconductor layer or said p-type nitride semiconductor layer is formed on a A-plane or M-plane of said substrate.
This application is a divisional of U.S. patent application Ser. No. 10/514,638, filed on Aug. 22, 2005, now abandoned, which is a �371 of International Application No. PCT/JP02/12969, filed on Dec. 11, 2002, which claims the benefit of U.S. application Ser. No. 10/147,318, filed on May 17, 2002, issued as U.S. Pat. No. 6,656,615, all of which are incorporated herein by reference.
The present invention relates to a structure wherein a single crystal nitride layer prepared by crystallization from supercritical ammonia-containing solution is used as a substrate or an intermediate layer of light emitting devices such as a laser structure etc.
In the nitride semiconductor laser, crystal defect or dislocation of a waveguide causes electron-hole pairs to make non-radiative recombination therein. Ideally, considering the laser function, the dislocation density in the waveguide may be 106/cm2 or less, preferably 104/cm2 or less. However, in the present situation, the dislocation density can not be reduced to less than 106/cm2 by using a vapor phase epitaxial growth (MOCVD and HVPE) or by using a repeated ELOG (Epitaxial lateral overgrowth), because the waveguide is grown on a heterogeneous substrate, such as sapphire substrate or SiC substrate.
To form a light emitting device comprising nitride semiconductor on a sapphire substrate or a SiC substrate without crack, the nitride semiconductor having the reduced dislocation density is required to be grown in the form of a thin layer on a sapphire substrate or a SiC substrate. If the nitride semiconductor is grown in the form of a thick layer on the substrate such as sapphire substrate etc, the curving of the substrate will be bigger, which leads to higher probability of crack occurrence. However, the nitride semiconductor in the form of a thin layer, in which the dislocation density is reduced, has not been realized by the vapor phase epitaxial growth.
To summarize the above, there has been a limitation to form a nitride semiconductor light emitting device (especially a laser device) by the vapor phase growth. Moreover, regarding the light emitting diode, in case that the higher luminance and higher output are required, the crystal dislocation of the substrate and of the intermediate layer will be a serious problem.
The first object of the present invention is to provide a light emitting device structure, which comprises a light emitting device comprising an n-type nitride semiconductor layer, an active layer comprising an In-containing nitride semiconductor, and a p-type nitride semiconductor layer, formed on a substrate for growth, wherein the light emitting device comprises a gallium-containing nitride semiconductor layer prepared by crystallization from supercritical ammonia-containing solution, instead of the so-far used vapor phase growth. The gallium-containing nitride semiconductor layer as one of the layers in the light emitting device is prepared by crystallization from supercritical ammonia-containing solution so that the crystalline quality of the layers formed on the gallium-containing nitride semiconductor layer can be recovered.
The second object of the present invention is to form a substrate for growth having low dislocation density by using a gallium-containing nitride bulk single crystal prepared by crystallization from supercritical ammonia-containing solution. Accordingly, the nitride semiconductor device formed on the substrate can be a nitride semiconductor with lower dislocation density. Concretely, this object is to form a nitride substrate having a lower dislocation density, i.e. 105/cm2 or less and more preferably 104/cm2 or less and to form thereon a light emitting device (laser structure etc.) having less crystal dislocation causing non-radiative recombination.
The third object of the present invention is to provide a light emitting device structure, such as a laser device etc, which comprises a high-resistance layer prepared by crystallization from supercritical ammonia-containing solution as a current confinement layer.
The inventors of the present invention found the following matters by using a technique wherein a gallium-containing nitride is recrystallized by crystallization from supercritical ammonia-containing solution, so-called AMMONO method:
the ratio of Ga/NH3 can remarkably be improved (over 20 times), compared with the ratio set by MOCVD vapor phase growth,
the bulk single crystal having a lower dislocation density can be obtained by AMMONO method at a very low temperature (600� C. or less), while the bulk single crystal is prepared by the vapor phase growth of the nitride at 1000� C. or more,
the lower dislocation density and recovery of the crystalline quality thereof can be realized despite the thin layer growth of the gallium-containing nitride, and
the single crystal substrate wherein the single crystal substrate is formed on A-plane or M-plane as an epitaxial growth face can be obtained, while such substrate would not be prepared by the so-far vapor phase growth.
The first invention is to provide a light emitting device structure comprising a gallium-containing nitride single crystal substrate, an n-type nitride semiconductor layer, an active layer comprising an In-containing nitride semiconductor, and a p-type nitride semiconductor layer, formed on the substrate, for growth prepared by the vapor phase growth, wherein a gallium-containing nitride semiconductor layer is formed to preserve the crystalline quality which would be degraded during the deposition of the layers in the light emitting device in the form of quaternary or ternary compound, such as InAlGaN, InGaN or AlGaN etc. on the substrate. Moreover, it is possible to recover the crystalline quality which would be detracted by newly occurred dislocation or impurity dopants during the depositing process of nitride semiconductor. The first invention is characterized in that the gallium-containing nitride semiconductor layer is formed by crystallization from supercritical ammonia-containing solution, so that the layer can become an epitaxial growth plane whose dislocation density thereon is 106/cm2 or less, preferably 104/cm2.
Specifically, the gallium-containing nitride has to be grown at the temperature which does not damage the active layer comprising an In-containing nitride semiconductor. In the AMMONO method, the nitride is grown at 600� C. or less, preferably 550� C. or less, therefore the single crystal GaN or AlGaN layer can be deposited on the active In-containing layer without the detraction of the active layer, although the growth temperature of 1000� C. or more is required in the vapor phase growth. The active layer comprising an In-containing nitride semiconductor is usually formed at 900� C., as lower temperature does not damage to the active layer from degradation etc. Furthermore, the crystalline quality can be recovered by the thin layer of less than several μm, preferably several hundreds Å and the dislocation density can also be reduced, so that the resulting laser device etc. is not subject to the stress.
The second invention is characterized in that the substrate is the gallium-containing nitride bulk single crystal prepared by crystallization from supercritical ammonia-containing solution, which leads to a light emitting device with lower dislocation density by the combination of the first invention and the second invention. Moreover, the substrate in the light emitting device structure has at least one plane selected from the group comprising A-plane, M-plane, R-plane, C-plane, {1-10n (n is a natural number)}, and {11-2m (m is a natural number)} of the gallium-containing nitride bulk single crystal, as its own surface.
According to the present invention, a nitride bulk single crystal shown in Drawings can be prepared by applying the AMMONO method, therefore A-plane or M-plane which is parallel to C-axis of hexagonal structure for an epitaxial growth can be obtained. (FIG. 9) In the present invention, an epitaxial growth required by a device structure can be carried out in case that the plane has the area of 100 mm2. A-plane and M-plane are non-polar, unlike C-plane. In case that A-plane or M-plane of the gallium-containing nitride is used as a plane for depositing of layers, there can be obtained a laser device having no cause of the deterioration of the performance such as the red shift of light emitting, recombination degradation and increase of the threshold current. According to the present invention, when the nitride semiconductor laser device is grown on A-plane of the GaN substrate prepared by crystallization from supercritical ammonia-containing solution, the active layer of the laser device is not subject to the polarization effect. In such a case, the light emitting face of the resonator will be M-plane, on which M-plane end face film can be formed and thus cleavage is easily performed. In case that the nitride semiconductor laser device is grown on M-plane of the GaN substrate prepared by crystallization from supercritical ammonia-containing solution, the active layer is not subject to the polarization effect and A-plane end face film being non-polar can be obtained on the light emitting face of the resonator.
According to the present invention, a substrate for growth means not only a substrate of only gallium-containing nitride but also a composite substrate (template) which comprises gallium-containing nitride grown on a heterogeneous substrate. In case that the gallium-containing nitride is formed on a heterogeneous substrate by crystallization from supercritical ammonia-containing solution, first GaN, AlN or AlGaN layer is preformed on the heterogeneous substrate and then the gallium-containing nitride is formed thereon.
The third invention is characterized by a light emitting device structure which comprises a light emitting device comprising an n-type nitride semiconductor layer, an active layer comprising an In-containing nitride semiconductor, and a p-type nitride semiconductor layer, formed on a substrate for growth, wherein the light emitting device comprises a layer in the form of high-resistance single crystal having a general formula AlxGa1-xN (0≦x≦1), prepared by crystallization from supercritical ammonia-containing solution as a current confinement layer. Accordingly, it is possible to limit the flowing position of the electric current and confine the current without forming the ridge in the laser device. Higher mixture ratio of Al in the crystal leads to the lower refraction index so as to confine the light efficiently. The current confinement layer made of AlN is preferred.
According to the present invention, aforementioned single crystal layer is usually in the form of a non-doped crystal. Even if AlGaN layer has non-uniform mixture ratio of crystal in direction of the thickness and then a tendency of decreased mixture ratio from the beginning of forming step is shown, there is no hindrance to the function as a current confinement layer. Furthermore, the layer can attain its function in the form of thin layer, i.e. several to several tens nm. Accordingly, when the AMMONO method is applied, alkali metal such as Na, K or Li etc, or alkali metal compound such as azide, amide, imide, amide-imide or hydride may be used as a mineralizer. Considering dissolving of the current confinement layer with the supercritical ammonia at the beginning of the AMMONO method, it is preferable that the thickness of the lower layer of the current confinement layer is set thicker than usual. When the current confinement layer or gallium-containing nitride semiconductor layer is prepared by the AMMONO method, it is recommended that a mask may be formed having the lower or same solubility in the supercritical ammonia. The formation of the mask can prevent the dissolution in the supercritical ammonia from the end face of the other layers of the nitride semiconductor, especially the dissolution of the active layer. The mask may be selected from the group consisting of SiO, SiN, AlN, Mo, W, and Ag. In the supercritical ammonia these materials for mask are more stable than GaN and the contact surface covered with the mask material can be prevented from the dissolution. In a later process, i.e. the process of formation of a ridge, the mask can be easily removed.
In the AMMONO method using the supercritical ammonia, a nitride semiconductor is grown in the supercritical ammonia wherein a gallium-containing nitride has the negative solubility curve. Detailed explanation of the method is disclosed in Polish Patent Application Nos. P-347918, P-350375 and PCT Application No. PCT/IB02/04185, so that those skilled in the art can easily carry out the present invention with reference to the abstract and examples explained below.
In the present invention, gallium-containing nitride or nitride is defined as below and as the general formula AlxGa1-x-yInyN, where 0≦x<1, 0≦y<1, and 0≦x+y<1, and may contain a donor, an acceptor, or a magnetic dopant, as required. For example, if the donor is doped, the nitride can be changed into n-type, so that the gallium-containing nitride semiconductor layer can be formed on a part of n-type nitride semiconductor layer. If acceptor is doped, the nitride can be changed into p-type, so that the gallium-containing nitride semiconductor layer is formed on a part of p-type nitride semiconductor layer. If a substrate for growth is a conductive substrate, a laser device (FIG. 1) or LED device (FIG. 4) having a pair of opposite electrodes can be obtained. It enables to introduce the huge electric current thereto.
As will be defined later, the supercritical solvent may contain NH3 and/or a derivative thereof. The mineralizer may contain alkali metal ions, at least, ions of lithium, sodium or potassium. On the other hand, the gallium-containing feedstock can be mainly composed of gallium-containing nitride or a precursor thereof. The precursor can be selected from an azide, imide, amidoimide, amide, hydride, intermetallic compound, alloy or metal gallium, each of which may contain gallium, as it is defined later.
According to the present invention, seeds for forming the substrate for growth can be comprised with GaN prepared by HVPE, crystals formed on the wall in the autoclave by spontaneous growth during crystallization from supercritical ammonia-containing solution, crystals prepared by flux method or crystals prepared by high-pressure method. It is preferable that a heterogeneous seed has a lattice constant of 2.8 to 3.6 with respect to ao-axis and a nitride semiconductor having a surface dislocation density of 106/cm2 or less is formed on the seed. Such a seed is selected from a body-centered cubic crystal system Mo or W, a hexagonal closest packing crystal system α-Hf or α-Zr, a tetragonal system diamond, a WC structure crystal system WC or W2C, a ZnO structure crystal system SiC, especially α-SiC, TaN, NbN or AlN, a hexagonal (P6/mmm) system AgB2, AuB2, HfB2 or ZrB2, and a hexagonal (P63/mmc) system γ-MoC ε-MbN or ZrB2. In order to make the surface property, the appropriate condition for crystal growth, Ga irradiation, NH3 process and Oxygen plasma process may be carried out as required, so that the heterogeneous seed has the Ga-polarity or N-polarity. Moreover, HCl process, HF process may be carried out, as required, to purify the surface. Or a GaN or AlN layer is formed on the heterogeneous seed by the vapor phase growth, so that the crystallization can effectively be carried out by crystallization from supercritical ammonia-containing solution. After such processes, gallium-containing nitride grown on the seed by polishing or wire saw, so as to prepare by a wafer for a substrate for growth.
The concentration of alkali metal ions in the supercritical solvent is adjusted so as to ensure the specified solubilities of feedstock and gallium-containing nitride, and the molar ratio of the alkali metal ions to other components of the supercritical solution is controlled within a range from 1:200 to 1:2, preferably from 1:100 to 1:5, more preferably from 1:20 to 1:8.
The present invention relates to a technique of an ammono-basic growth of crystal which comprises a chemical transport in a supercritical ammonia-containing solvent containing at least one mineralizer for imparting an ammono-basic property, to grow a single crystal of gallium-containing nitride. This technique has a very high originality, and therefore, the terms herein used should be understood as having the meanings defined as below in the present specification.
The term “gallium-containing nitride” in the specification means a compound which includes at least gallium and nitrogen atom as a consistent element. It includes the binary compound GaN, ternary compounds such as AlGaN, InGaN or also quaternary compounds AlInGaN, where the range of the other elements to gallium can vary, in so far as the crystallization growth technique of ammonobasic is not hindered.
The term “gallium-containing nitride bulk single crystal” means a gallium-containing nitride single crystal substrate on which an optic or electronic device such as LED or LD can be prepared by an epitaxial growth process such as MOCVD, HVPE or the like.
The term “a precursor of gallium-containing nitride” means a substance which may contain at least gallium, and if needed, an alkali metal, an element of the Group XIII, nitrogen and/or hydrogen, or a mixture thereof, and examples of such a precursor include metallic Ga, an alloy or an intermetallic compound of Ga, and a hydride, amide, imide, amido-imide or azide of Ga, which can form a gallium compound soluble in a supercritical ammonia-containing solvent as defined below.
The term “supercritical ammonia-containing solvent” means a supercritical solvent which may contain at least ammonia, and ion or ions of at least one alkali metal for dissolving gallium-containing nitride.
The term “mineralizer” means a supplier for supplying one or more of alkali metal ions (Li, K, Na or Cs) for dissolving gallium-containing nitride in the supercritical ammonia-containing solvent. Concretely, the mineralizer is selected from the group consisting of Li, K, Na, Cs, LiNH2, KNH2, NaNH2, CsNH2, LiH, KH, NaH, CsH, Li3N, K3N, Na3N, Cs3N, Li2NH, K2NH, Na2NH, Cs2NH, LiNH2, KNH2, NaNH2, CsNH2, LiN3, KN3, NaN3 and CsN3. The phrase “dissolution of gallium-containing feedstock” means a reversible or irreversible process in which the feedstock takes the form of a gallium compound soluble in the supercritical solvent such as a gallium complex compound. The gallium complex compound means a complex compound in which a gallium atom as a coordination center is surrounded by ligands, e.g., NH3 or derivatives thereof such as NH2 − and NH2−.
The term “supercritical ammonia-containing solution” means a solution including a soluble gallium-containing compound formed by dissolution of gallium-containing feedstock in the supercritical ammonia-containing solvent. Based on our experiments, we have found that there is an equilibrium relationship between the gallium-containing nitride solid and the supercritical solution under a sufficiently high temperature and pressure conditions. Accordingly, the solubility of the soluble gallium-containing nitride can be defined as the equilibrium concentration of the above soluble gallium-containing compound in the presence of solid gallium-containing nitride. In such a process, it is possible to shift this equilibrium by changing in temperature and/or pressure.
The phrase “negative temperature coefficient of solubility” shown in the gallium-containing nitride in the supercritical ammonia means that the solubility is expressed by a monotonically decreasing function of the temperature, when all other parameters are kept constant. Similarly, the phrase “positive pressure coefficient of solubility” means that the solubility is expressed by a monotonically increasing function of the pressure, when all other parameters are kept constant. Based on our research, the solubility of gallium-containing nitride in the supercritical ammonia-containing solvent has a negative temperature coefficient at least within the range of 300 to 550� C., and a positive pressure coefficient at least within the range of 1 to 5.5 kbar.
The phrase “supersaturation of the supercritical ammonia-containing solution of gallium-containing nitride” means that the concentration of the soluble gallium compounds in the above supercritical ammonia-containing solution is higher than the concentration in the equilibrium state, i.e., the solubility of gallium-containing nitride. In case of the dissolution of gallium-containing nitride in a closed system, such supersaturation can be achieved, according to the negative temperature coefficient or a positive pressure coefficient of solubility, by raising the temperature or reducing the pressure.
The chemical transport from the lower temperature dissolution zone to higher temperature crystallization zone is important for gallium-containing nitride in the supercritical ammonia-containing solution. The phrase “the chemical transport” means a sequential process including the dissolution of gallium-containing feedstock, the transfer of the soluble gallium compound through the supercritical ammonia-containing solution, and the crystallization of gallium-containing nitride from the supersaturated supercritical ammonia-containing solution. In general, a chemical transport process is carried out by a certain driving force such as a temperature gradient, a pressure gradient, a concentration gradient, difference in chemical or physical properties between the dissolved feedstock and the crystallized product, or the like. Preferably, the chemical transport in the process of the present invention is achieved by carrying out the dissolution step and the crystallization step in separate zones, provided that the temperature of the crystallization zone is maintained higher than that of the dissolution zone, so that the gallium-containing nitride bulk single crystal can be obtained by the processes of this invention.
The term “seed” has been described above. According to the present invention, the seed provides a region or area on which the crystallization of gallium-containing nitride is allowed to take place. Seed may be a laser device or LED device, whose surface is exposed for forming a current confinement layer. Moreover, the growth quality of the crystal depends on the quality of the seed for forming the substrate for growth. Thus, the seed of a high quality should be selected.
The term “spontaneous crystallization” means an undesirable phenomenon in which the formation and the growth of the core of gallium-containing nitride from the supersaturated supercritical ammonia-containing solution occur at any site inside the autoclave, and the spontaneous crystallization also includes disoriented growth of the crystal on the surface of the seed.
The term “selective crystallization on the seed” means a step of allowing the crystallization to take place on the surface of the seed, accompanied by substantially no spontaneous growth. This selective crystallization on the seed is essential for the growth of a bulk single crystal, it is also one of the conditions to form aforementioned gallium-containing nitride semiconductor layer, electric current confinement layer and a substrate for growth by applying crystallization from supercritical ammonia-containing solution.
In this regard, the temperature distribution in the autoclave, as described later in the part of Examples, is determined by using an empty autoclave, i.e. without the supercritical ammonia, and thus, the supercritical temperature is not the one actually measured. On the other hand, the pressure in the autoclave is directly measured, or it is determined by the calculation from the amount of ammonia initially introduced, and the temperature and the volume of the autoclave.
It is preferable to use an apparatus as described below, to carry out the above process. An apparatus according to the present invention provides an autoclave for preparing the supercritical solvent, characterized in that a convection control means for establishing a convention flow is arranged in the autoclave, and a furnace unit is equipped with a heater or a cooler.
The furnace unit includes a higher temperature zone, equipped with a heater, which corresponds to the crystallization zone in the autoclave, and a lower temperature zone, equipped with a heater or a cooler, which corresponds to the dissolution zone in the autoclave. The convection control means may be composed of at least one horizontal baffle having a central opening and/or a periphery space and dividing the crystallization zone from the dissolution zone. Inside the autoclave, the feedstock is located in the dissolution zone, and the seed is located in the crystallization zone, and convection flow in the supercritical solution between two zones is controlled by the convection control means. It is to be noted that the dissolution zone is located above the horizontal baffle, and the crystallization zone, below the horizontal baffle.
Crystallization from supercritical ammonia-containing solution (AMMONO method) is summarized as follows. In the reaction system, the negative dissolution curve (negative temperature coefficient of solubility) means that the solubility of the nitride semiconductor is lower in the higher temperature zone and the solubility thereof is higher in the lower temperature zone. When the temperature difference is controlled properly in the higher temperature zone and the lower temperature zone inside the autoclave, the nitride are dissolved in the lower temperature zone and it is recrystallized in the higher temperature zone. Due to the generated convection flow from the lower temperature zone to the higher temperature zone, a predetermined concentration of nitrides can be kept in the higher temperature zone and the nitrides can be selectively grown on the seed. Moreover, the aspect ratio (longitudinal direction/lateral direction) in the reaction system inside the autoclave is preferably set 10 or more, so that the convection flow does not stop. The convection control means is located within the range from ⅓ to ⅔ of the total length of the inner chamber of the autoclave. The ratio of opening in the horizontal baffle on the cross-sectional area is set at 30% or less, so that the spontaneous crystallization can be prevented.
The wafer is thus placed in the higher temperature zone, and the feedstock in the lower temperature zone in the reaction system inside the autoclave. Dissolution of the feedstock in the lower temperature zone leads to the supersaturation. In the reaction system, a convection flow is generated, due to which the dissolved feedstock flows to the higher temperature zone. Due to a lower solubility at the higher temperature zone, the dissolved feedstock becomes recrystallized on the wafer which is the seed. Recrystallization carried out in this way results in forming a bulk single crystal layer. Moreover, a characteristic feature of this method, as compared to the methods by which nitride semiconductor is formed from the vapor phase growth at temperature over 900� C., is the fact that it allows growth of nitride semiconductor at a temperature preferably 600� C. or less, and more preferably 550� C. or less. Due to this, in the wafer placed in the higher temperature zone a thermal degradation of the active In-containing layer does not occur.
The material of the feedstock depends on the composition of the single crystal layer. In case that GaN is used, GaN single crystal, GaN poly crystal, GaN precursor or metallic Ga can generally be used, GaN single crystal or GaN poly crystal can be formed and then recrystallized. GaN prepared by the vapor phase growth, such as HVPE method or MOCVD method, by AMMONO method, by flux method or by high pressure method can be used. GaN powder in the form of a pellet can also be used. The precursor of GaN may contain gallium azide, gallium imide, gallium amide or the mixture thereof. In case of AlN—similarly as GaN—AlN single crystal, AlN poly crystal, AlN precursor or metallic Al is used, AlN single crystal or AlN poly crystal can be formed and then recrystallized. AlGaN is a mixed crystal of AlN and GaN, and the feedstock thereof may be mixed appropriately. Moreover, the usage of metal and single crystal or poly crystal (for example, metallic Al and GaN single crystal or poly crystal) and preferably adding more than two kinds of mineralizer etc. can lead to a predetermined composition.
It is possible to use alkali metals, such as Li, Na, K, Cs or complexes of alkali metals, such as alkali metal azide, alkali metal amide, alkali metal imide as a mineralizer. A molar ratio of the alkali metal to ammonia ranges from 1:200 to 1:2. Li is preferably used. Li is a mineralizer, for which the solubility of nitride is low, which leads to restraint of dissolution of the uncovered nitride semiconductor device, preventing the spontaneous crystallization and effective formation of the thin layers of the thickness from ten to several tens nm.
FIG. 1 is a schematic cross-sectional view of the end face of the nitride semiconductor laser device according to the present invention.
FIG. 2A-2E represent the schematic cross-sectional view illustrating a manufacturing process of the nitride semiconductor laser device, in case of the preferred embodiment according to the present invention.
FIGS. 3A and 3B represent the schematic cross-sectional view of the end face of the nitride semiconductor laser device according to the present invention.
FIG. 4A to 4F represent the schematic cross-sectional view illustrating a manufacturing process of the nitride semiconductor laser device, in case of the preferred embodiment according to the present invention.
FIG. 5 is a schematic cross-sectional view of the nitride semiconductor LED device according to the present invention.
FIG. 6 is a schematic view of the nitride semiconductor LED device according to the present invention.
FIG. 7 is a schematic view of the nitride semiconductor LED device according to the present invention.
FIG. 8 is a schematic view of the nitride semiconductor LED device according to the present invention.
FIG. 9 presents a frame format of the substrate in which A-plane being parallel to c-axis is cut out from the bulk single crystal and a light emitting end face is formed on M-plane.
The schematic cross-sectional view of the semiconductor laser according to the present invention is shown in FIG. 1. On the substrate 1 for growth, the n-type nitride semiconductor layer 2 and the p-type nitride semiconductor layer 4 are formed. Between them there is the active layer 3 of a single quantum well or a multi quantum well structure in the form of an In-containing nitride semiconductor. This results in the laser device having a good light emitting efficiency at the wavelength region between near-ultraviolet and green visible light (from 370 nm to 550 nm). The n-type nitride semiconductor layer 2 is composed of an n-type contact layer 21, a InGaN crack-preventing layer 22, an n-type AlGaN clad layer 23 and an n-type GaN optical guide layer 24. The n-type contact layer 21 and the crack-preventing layer 22 can be omitted. The p-type nitride semiconductor layer 4 is composed of a cap layer 41, a p-type AlGaN optical guide layer 42, a p-type AlGaN clad layer 43 and a p-type GaN contact layer 44. According to the present invention, gallium-containing nitride semiconductor layer prepared by the crystallization from supercritical ammonia-containing solution can be used in the n-type nitride semiconductor layer 2 or p-type nitride semiconductor layer 4. The substrate 1 is comprised with a bulk single crystal and the dislocation thereof is remarkably low, i.e. about 104/cm2. Therefore, the n-type contact layer 21 can be formed without ELO layer for decreasing dislocation, AlGaN layer for decreasing the pits or buffer layer. The substrate is a conductive substrate and n-type electrode is formed below the substrate so that the p-type electrode and the n-type electrode compose a face-type electrodes structure. In the above embodiment, the resonator of the semiconductor laser device is composed of the active layer 3, the p-type optical guide layer 24, n-type optical guide layer 42 and the cap layer 41.
Further herein the typical manufacturing method of the nitride semiconductor laser device of the present embodiment is provided.
FIG. 2A to 2E illustrate the process which comprises the steps of forming a laser device on the C-plane using a conductive GaN substrate as a substrate for growth and a n-type electrode below the substrate.
FIG. 4A to 4E illustrate the process which comprises the steps of forming a n-type nitride semiconductor layer 2, an active layer 3 and a first p-type nitride semiconductor layer 4A of a laser device, and then forming a current confinement layer 5 by crystallization from supercritical ammonia-containing solution, and finally forming a second p-type nitride semiconductor layer 4B. Next, after growing a nitride semiconductor layer, a p-type electrode is formed on the second p-type nitride semiconductor layer 4B and n-type electrode is formed below the substrate for growth so that a laser device can be obtained.
The first method shown in FIG. 2, the conductive substrate for growth is first prepared. (FIG. 2A) Next, the wafer is prepared on the C-plane of Substrate 1 by depositing successively the n-type nitride semiconductor layer 2 composed of an n-type contact layer 21, a crack-preventing layer 22, an n-type clad layer 23 and an n-type optical guide layer 24, then the active layer 3 and finally the p-type nitride semiconductor layer 4 composed of a protective layer 41, a p-type optical guide layer 42, a p-type clad layer 43 and a p-type contact layer 44. (FIG. 2B) According to the present invention, a gallium-containing nitride semiconductor layer prepared by crystallization from supercritical ammonia-containing solution is intercalated in the n-type nitride semiconductor layer and/or the p-type nitride semiconductor layer so that the crystalline quality of the laser device can be recovered. In this process, since the substrate for growth is used, the dislocation of the epitaxial layer can be decreased without forming the n-type nitride semiconductor layer 2 through a buffer layer prepared at the low temperature an ELO layer. The n-type contact layer 21 or the crack preventing layer 22 can be omitted.
Next, the wafer is etched and a ridge is formed. Then the buried layer 70 is formed to cover the ridge and next the p-type electrode 80 is formed. The ridge stripe which performs the optical wave guide is formed in the direction of the resonator. The width of the ridge is from 1.0 μm to 20 μm and the ridge reaches the p-type clad layer or the p-type guide layer. The buried layer is made of SiO2 film or ZrO2 film etc. A p-type ohmic electrode 80 is formed to be in contact with the p-type contact layer 43 which is on the top surface of the ridge. Both of single ridge and plural ridges can be used. A multi-stripe-type laser device can be obtained by plural ridges. Next, a p-type pad electrode is formed. Moreover, a SiO2/TiO2 serves as a reflecting film for laser oscillation due to an alternate arrangement and a patterning of the SiO2 and TiO2 layers. Finally, each nitride semiconductor laser device is cut out from the wafer by scribing. In this way a finished nitride semiconductor laser device is obtained. (FIG. 2E, FIG. 1)
FIG. 4A to 4E illustrate the process of manufacturing a laser device comprising a current confinement layer. A-plane of the substrate 1 is cut out from the bulk single crystal as illustrated in FIG. 9 and used as a substrate, and a light emitting end face is M-plane so that a laser device can be obtained by cleavage. On the substrate 1 for growth the n-type nitride semiconductor layer 2 and the active layer 3 are deposited successively. Next, the first p-type nitride semiconductor layer 4A is formed. (FIG. 4A) The same reference numeral is given to the same element to omit the explanation. Next, the first p-type nitride semiconductor layer 4A is prepared by etching in the form of convex-shape. (FIG. 4B) Then, the current confinement layer 5 is prepared by crystallization from supercritical ammonia-containing solution using the gallium-containing nitride semiconductor layer. (FIG. 4C) Further, the second p-type nitride semiconductor layer 4B is formed. (FIG. 4D) The p-type ohmic electrode 80 is formed to be in contact with the second p-type nitride semiconductor layer 4B. Next, the n-type electrode 90 is formed below the substrate 1. (FIG. 4E) Next, the p-type pad electrode 110 is formed. Next, the light emitting end face is formed by cleavage, so that the wafer becomes in the form of a bar. After such process, the light emitting film may be formed on the light emitting end face so as to obtain a laser device by cleaving. The current confinement layer 5 can be arranged at the side of the p-type nitride semiconductor layer (FIG. 3A) or n-type nitride semiconductor layer (FIG. 3B)
In case that the current confinement layer 5 is formed, the single crystal AlGaN layer can be formed at a low temperature, i.e. from 500� C. to 600� C., by applying crystallization from supercritical ammonia-containing solution. P-type nitride layer can be formed without degradation of the active In-containing layer.
FIG. 5 illustrates the obtained LED device having a gallium-containing nitride semiconductor layer prepared by crystallization from supercritical ammonia-containing solution.
After the gallium-containing nitride semiconductor layer 202 is formed directly on the conductive substrate 201 without forming buffer layer prepared at low temperature, a modulation doped layer 203 composed of undoped GaN/Si doped GaN/undoped GaN and an active layer 205 composed of InGaN well layer/GaN barrier layer through a superlattice layer 204 are formed. LED is obtained by successively depositing a p-type clad layer 206, an undoped AlGaN layer 207 and a p-type contact layer 208 on the top surface of the active layer 205. The p-type electrode 209 and n-type electrode 210 are simultaneously formed on the p-type contact layer 208 and below the substrate 201, respectively.
According to the present invention, the gallium-containing nitride semiconductor layer 202 can be formed instead of the modulation doped layer 203 and the superlattice layer 204, while the n-type contact layer is formed on one bottom side, and the gallium-containing nitride semiconductor layer 202 can be formed on the active layer. As described above, AMMONO method which enables to form the single crystal at a low temperature allows simplifying the device structure as well as recovering the crystalline quality and decreasing the dislocation density.
The GaN substrate 1 doped with Si of 2 inch diameter on C-plane as a growth face is placed in a MOCVD reactor. Temperature is set at 1050� C. Hydrogen is used as a carrier gas, and ammonia and TMG (thrimethylgallium) are used as gaseous materials.
(2) n-type clad layer, in the form of the superlattice of the total thickness being 1.2 μm, formed by alternate deposition of 25 angstroms thickness undoped Al0.1Ga0.9N layer and n-type GaN layer doped with Si at the level of 1�1019/cm3.
(3) a wafer is introduced into the reactor (autoclave), inside which is filled with the supercritical ammonia. Having been filled with the feedstock in the form of GaN of 0.5 g, ammonia of 14.7 g and mineralizer in the form of Li of 0.036 g, the autoclave (36 cm3) is tightly closed at a temperature 500� C. or less inside the autoclave. The internal chamber of the autoclave is divided into two zones: the higher temperature zone and the lower temperature zone. In the higher temperature zone of 550� C. there is a wafer, whereas in the lower temperature zone of 450� C. there is feedstock in the form of GaN and Ga metal. The sealed autoclave is left for three days. Under the low temperature condition, the layer for recovering the crystalline quality of 100 angstrom thickness in the form of single crystal GaN is grown in supercritical ammonia.
(4) Then the wafer is taken out from the autoclave and set in the MOCVD reactor device at a temperature of 1050� C. 0.2 μm thickness undoped GaN n-type optical guide layer.
(5) an active layer of the total thickness being 380 angstroms in the form of layers alternately arranged, i.e. barrier layer/well layer/barrier layer/well layer/barrier layer, wherein 100 angstroms thickness with Si doped In0.05Ga0.95N layer forms a barrier layer, and 40 angstroms thickness undoped In0.1Ga0.9N layer forms a quantum well layer.
(7) p-type clad layer in the form of the superlattice of the total thickness being 0.6 μm, formed by alternate deposition of 25 angstroms thickness undoped Al0.16Ga0.84N layer and 25 angstroms thickness undoped GaN layer.
After the above layers are deposited, the formed wafer is subject to annealing at 700� C. in the MOCVD reactor device under the nitrogen atmosphere, due to which the resistance of the p-type nitride semiconductor layer is additionally reduced.
After annealing, the wafer is taken out from the reactor and a protective film (mask) in the form of SiO2 stripe is deposited on the surface of the top p-type contact layer. Next, by using RIE method, the wafer is etched and a stripe is formed, uncovering thereby end faces of the resonator and the surface of the n-type contact layer. The SiO2 protective film (mask) formed on the surface of the p-type contact layer is removed by using the wet etching method.
Next, under the low temperature condition, in the supercritical ammonia 100, angstrom thick single crystal GaN end face film is grown on the stripe end face, stripe lateral face and uncovered surfaces of the p-type contact layer.
After a single crystal GaN end face film, which can be omitted, is formed, the single crystal GaN formed on the surface of the top p-type contact layer is removed by etching. Next, the surface of the p-type contact layer is covered with the SiO2 mask in the form of 1.5 μm wide strips and etching of the p-type clad layer is continued until a ridge is formed on the strip part. Etching is carried out until thickness of the p-type clad layer becomes 0.1 μm on both sides of ridge.
Next the p-type electrode 80 in the form of Ni/Au is formed on the p-type contact layer, so that an ohmic contact would appear, and the n-type electrode 90 in the form of Ti/Al below the substrate 1. Then, the wafer is subject to the thermal processing at 600� C. Next, pad electrode in the form of Ni(1000 Å)-Ti(1000 Å)-Au(8000 Å) is laid on the p-type electrode. After a reflecting film 100 in the form of SiO2 and TiO2 is formed, each nitride semiconductor laser device is cut out from the wafer by scribing.
Each nitride semiconductor laser device manufactured in this way is equipped with a heat sink and the laser oscillation is carried out. Due to an increased COD level, prolonged continuous oscillation time is expected—with threshold current density: 2.0 kA/cm2, power output: 100 mW, preferably 200 mW, and 405 nm oscillation wavelength.
GaN substrate 1 for growth doped with Si is prepared by crystallization from supercritical ammonia-containing solution, whereas other stages of production of the nitride semiconductor laser device are carried out similarly as in Example 1.
First, a GaN substrate 1 doped with Si of 2 inch diameter on C-plane as a growth face is placed in a MOCVD reactor. Temperature is set at 1050� C. Hydrogen is used as a carrier gas, and ammonia and TMG (thrimethylgallium) are used as gaseous materials.
(1) 4 μm thickness n-type GaN contact layer, doped with Si at the level of 3�108/cm3.
(2) n-type clad layer, in the form of the superlattice of the total thickness being 1.2 μm, formed by alternate deposition of 25 angstroms thickness undoped Al0.1Ga0.9N layers and n-type GaN layers doped with Si at the level of 1�109/cm3.
(3) 0.2 μm thickness undoped GaN n-type optical guide layer.
(5) the p-type optical guide layer undoped GaN of 0.2 μm as a first p-type nitride semiconductor layer.
(6) Next, the first p-type nitride semiconductor layer except the area for the passage of a current is removed by etching. (FIG. 4B)
(7) the wafer is introduced into the reactor (autoclave), inside which is filled with supercritical ammonia. Having been filled with the feedstock in the form of Al of 0.5 g, ammonia of 14.7 g and mineralizer in the form of Li of 0.036 g, the autoclave (36 cm3) is tightly closed at a temperature 500� C. or less inside the autoclave. The internal chamber of the autoclave is divided into two zones: the higher temperature zone and the lower temperature zone. In the higher temperature zone of 550� C. there is a wafer, whereas in the lower temperature zone of 450� C. there is feedstock in the form of Al metal. The sealed autoclave is left for three days. Under the low temperature condition the current confinement layer 5 of 100 angstrom thickness in the form of Al is grown in supercritical ammonia.
(8) the wafer is taken out from the autoclave and set in the MOCVD reactor device at a temperature of 1050� C. The p-type clad layer as the second p-type nitride semiconductor layer in the form of the superlattice of the total thickness being 0.6 μm, formed by alternate deposition of 25 angstroms thickness undoped Al0.16Ga0.84N layer and 25 angstroms thickness undoped GaN layer.
(9) 150 angstroms thick p-type contact layer of p-type GaN doped with Mg at the level of 1�1020/cm3.
After annealing, the wafer is taken out from the reactor.
After a single crystal GaN end face film, which can be omitted, is formed on the light emitting face, the single crystal GaN formed on the surface of the top p-type contact layer is removed by etching. Next, the p-type electrode 80 in the form of Ni/Au is formed on the surface of the p-type contact layer so that an ohmic contact would appear, and the n-type electrode 90 in the form of Ti/Al below the substrate 1. Then, the wafer is subject to the thermal processing at 600� C. Next, pad electrode in the form of Ni(1000 Å)-Ti(1000 Å)-Au(8000 Å) are laid on the p-type electrode. After a reflecting film 100 in the form of SiO2 and TiO2 is formed, each nitride semiconductor laser device is cut out from the wafer by scribing.
Each nitride semiconductor laser device manufactured in this way is equipped with a heat sink and the laser oscillation is carried out. Due to the increase of a COD level, prolonged continuous oscillation time is expected—with threshold current density: 2.0 kA/cm2, power output: 100 mW, preferably 200 mW, and 405 nm oscillation wavelength.
As described above, since the nitride semiconductor light emitting device according to the present invention comprises a gallium-containing nitride semiconductor layer prepared by crystallization from supercritical ammonia-containing solution, the crystalline quality can be recovered, while otherwise it would be degraded after forming the layer of quaternary or ternary compound. As the result there can be provided a laser device which is excellent in the lifetime property and current resistant property.
Moreover, non-polar nitride A-plane or non-polar nitride M-plane is cut out from the bulk single crystal, the substrate for growth is prepared in this way, and the laser device can be formed on the A-plane or M-plane as an epitaxial growth face. Thus, there can be obtained the laser device wherein the active layer is not influenced by the polarization and there is no cause of the deterioration of the performance such as the red shift of light emitting, recombination degradation and increase of the threshold current.
Furthermore, in case that the current confinement layer is formed at a lower temperature, the laser device can be obtained without the device degradation, and the process for forming the ridge can be omitted.
Moreover, the nitride layer can be formed in the form of single crystal at low temperature, so that the active In-containing layer is not influenced by degradation or damaged. Therefore the function and lifetime of the device can be improved.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS5096860May 25, 1990Mar 17, 1992Alcan International LimitedProcess for producing unagglomerated single crystals of aluminum nitrideUS5147623Mar 28, 1991Sep 15, 1992Korea Institute Of Science And TechnologyFabrication method of cubic boron nitrideUS5190738Jun 17, 1991Mar 2, 1993Alcan International LimitedProcess for producing unagglomerated single crystals of aluminum nitrideUS5306662Nov 2, 1992Apr 26, 1994Nichia Chemical Industries, Ltd.Method of manufacturing P-type compound semiconductorUS5456204May 28, 1993Oct 10, 1995Alfa Quartz, C.A.Filtering flow guide for hydrothermal crystal growthUS5589153Jun 2, 1995Dec 31, 1996The Dow Chemical CompanySynthesis of crystalline porous solids in ammoniaUS5679965Nov 9, 1995Oct 21, 1997North Carolina State UniversityIntegrated heterostructures of Group III-V nitride semiconductor materials including epitaxial ohmic contact, non-nitride buffer layer and methods of fabricating sameUS5780876Apr 22, 1996Jul 14, 1998Sharp Kabushiki KaishaCompound semiconductor light emitting device and manufacturing method thereofUS5868837Jan 13, 1998Feb 9, 1999Cornell Research Foundation, Inc.Low temperature method of preparing GaN single crystalsUS5928421Aug 26, 1997Jul 27, 1999Matsushita Electronics CorporationMethod of forming gallium nitride crystalUS6031858Sep 9, 1997Feb 29, 2000Kabushiki Kaisha ToshibaSemiconductor laser and method of fabricating sameUS6046464Aug 13, 1997Apr 4, 2000North Carolina State UniversityIntegrated heterostructures of group III-V nitride semiconductor materials including epitaxial ohmic contact comprising multiple quantum wellUS6051145Jan 25, 1999Apr 18, 2000Hydroprocessing, LlcMethod for handling an effluent in a hydrothermal processUS6067310Sep 5, 1997May 23, 2000Sumitomo Electric Industries, Ltd.Semiconductor laser and method of making the sameUS6139628Apr 8, 1998Oct 31, 2000Matsushita Electronics CorporationMethod of forming gallium nitride crystalUS6150674Nov 4, 1999Nov 21, 2000Matsushita Electronics CorporationSemiconductor device having Alx Ga1-x N (0<x<1) substrateUS6153010Apr 9, 1998Nov 28, 2000Nichia Chemical Industries Ltd.Method of growing nitride semiconductors, nitride semiconductor substrate and nitride semiconductor deviceUS6156581Dec 3, 1997Dec 5, 2000Advanced Technology Materials, Inc.GaN-based devices using (Ga, AL, In)N base layersUS6172382Jan 9, 1998Jan 9, 2001Nichia Chemical Industries, Ltd.Nitride semiconductor light-emitting and light-receiving devicesUS6177057Feb 9, 1999Jan 23, 2001The United States Of America As Represented By The Secretary Of The NavyProcess for preparing bulk cubic gallium nitrideUS6177292Dec 5, 1997Jan 23, 2001Lg Electronics Inc.Method for forming GaN semiconductor single crystal substrate and GaN diode with the substrateUS6248607Sep 7, 1999Jun 19, 2001Rohn Co., Ltd.Method for manufacturing semiconductor light emitting deviceUS6249534Apr 5, 1999Jun 19, 2001Matsushita Electronics CorporationNitride semiconductor laser deviceUS6252261Jun 28, 1999Jun 26, 2001Nec CorporationGaN crystal film, a group III element nitride semiconductor wafer and a manufacturing process thereforUS6258617Aug 30, 1996Jul 10, 2001Kabushiki Kaisha ToshibaMethod of manufacturing blue light emitting elementUS6265322Sep 21, 1999Jul 24, 2001Agere Systems Guardian Corp.Selective growth process for group III-nitride-based semiconductorsUS6270569Jun 11, 1998Aug 7, 2001Hitachi Cable Ltd.Method of fabricating nitride crystal, mixture, liquid phase growth method, nitride crystal, nitride crystal powders, and vapor phase growth methodUS6303403Dec 27, 1999Oct 16, 2001Futaba Denshi Kogyo, K.K.Method for preparing gallium nitride phosphorUS6329215Jun 3, 1998Dec 11, 2001Centrum Badan Wysokocisnieniowych Polskiej Akademii NavkMethod of fabrication of semiconducting compounds of nitrides A3B5 of P-and N-type electric conductivityUS6335546Jul 30, 1999Jan 1, 2002Sharp Kabushiki KaishaNitride semiconductor structure, method for producing a nitride semiconductor structure, and light emitting deviceUS6355497Jan 18, 2000Mar 12, 2002Xerox CorporationRemovable large area, low defect density films for led and laser diode growthUS6372041Jan 7, 2000Apr 16, 2002Gan Semiconductor Inc.Method and apparatus for single crystal gallium nitride (GaN) bulk synthesisUS6380051Jun 21, 1999Apr 30, 2002Sharp Kabushiki KaishaLayered structure including a nitride compound semiconductor film and method for making the sameUS6398867 *Oct 6, 1999Jun 4, 2002General Electric CompanyCrystalline gallium nitride and method for forming crystalline gallium nitrideUS6399500Mar 13, 1998Jun 4, 2002Centrum Badan Wysokocisnieniowych PanMechano-chemical polishing of crystals and epitaxial layers of GaN and Ga1-x-yA1xInyNUS6399966Sep 7, 2001Jun 4, 2002Sharp Kabushiki KaishaLight emitting nitride semiconductor device, and light emitting apparatus and pickup device using the sameUS6407409Apr 16, 2001Jun 18, 2002Gan Semiconductor, Inc.Method and apparatus for single crystal gallium nitride (GAN) bulk synthesisUS6423984Sep 10, 1999Jul 23, 2002Toyoda Gosei Co., Ltd.Light-emitting semiconductor device using gallium nitride compound semiconductorUS6447604Jun 28, 2000Sep 10, 2002Advanced Technology Materials, Inc.Method for achieving improved epitaxy quality (surface texture and defect density) on free-standing (aluminum, indium, gallium) nitride ((al,in,ga)n) substrates for opto-electronic and electronic devicesUS6459712Jul 2, 2001Oct 1, 2002Hitachi, Ltd.Semiconductor devicesUS6468882Jul 10, 2001Oct 22, 2002Sumitomo Electric Industries, Ltd.Method of producing a single crystal gallium nitride substrate and single crystal gallium nitride substrateUS6475277Jun 29, 2000Nov 5, 2002Sumitomo Electric Industries, Ltd.Group III-V nitride semiconductor growth method and vapor phase growth apparatusUS6488767Jun 8, 2001Dec 3, 2002Advanced Technology Materials, Inc.High surface quality GaN wafer and method of fabricating sameUS6509651Jul 12, 1999Jan 21, 2003Sumitomo Electric Industries, Ltd.Substrate-fluorescent LEDUS6531072Aug 9, 2000Mar 11, 2003Futaba CorporationPhosphorUS6534795Nov 27, 2001Mar 18, 2003Ngk Insulators, Ltd.Semiconductor light-emitting elementUS6562466Jul 2, 2001May 13, 2003Essilor International Compagnie Generale D'optiqueProcess for transferring a coating onto a surface of a lens blankUS6586762Jul 5, 2001Jul 1, 2003Nichia CorporationNitride semiconductor device with improved lifetime and high output powerUS6592663Jun 8, 2000Jul 15, 2003Ricoh Company Ltd.Production of a GaN bulk crystal substrate and a semiconductor device formed on a GaN bulk crystal substrateUS6593589Jan 29, 1999Jul 15, 2003The University Of New MexicoSemiconductor nitride structuresUS6596079Mar 13, 2000Jul 22, 2003Advanced Technology Materials, Inc.III-V nitride substrate boule and method of making and using the sameUS6614824Sep 13, 2001Sep 2, 2003Sharp Kabushiki KaishaNitride semiconductor laser device and optical device using the sameUS6627552Mar 28, 2001Sep 30, 2003Kabsuhiki Kaisha ToshibaMethod for preparing epitaxial-substrate and method for manufacturing semiconductor device employing the sameUS6639925Sep 28, 2001Oct 28, 2003Hitachi, Inc.Optical information processing equipment and semiconductor light emitting device suitable thereforUS6653663Dec 5, 2000Nov 25, 2003Matsushita Electric Industrial Co., Ltd.Nitride semiconductor deviceUS6656615May 17, 2002Dec 2, 2003Nichia CorporationBulk monocrystalline gallium nitrideUS6657232Apr 16, 2001Dec 2, 2003Virginia Commonwealth UniversityDefect reduction in GaN and related materialsUS6677619Nov 17, 2000Jan 13, 2004Nichia Chemical Industries, Ltd.Nitride semiconductor deviceUS6686608Sep 7, 2000Feb 3, 2004Sharp Kabushiki KaishaNitride semiconductor light emitting deviceUS6693935Jun 19, 2001Feb 17, 2004Sony CorporationSemiconductor laserUS6711191Mar 3, 2000Mar 23, 2004Nichia CorporationNitride semiconductor laser deviceUS6720586Nov 15, 2000Apr 13, 2004Matsushita Electric Industrial Co., Ltd.Method of fabricating nitride semiconductor, method of fabricating nitride semiconductor device, nitride semiconductor device, semiconductor light emitting device and method of fabricating the sameUS6749819Jul 19, 2001Jun 15, 2004Japan Pionics Co., Ltd.Process for purifying ammoniaUS6858882Sep 4, 2001Feb 22, 2005Sharp Kabushiki KaishaNitride semiconductor light-emitting device and optical device including the sameUS6924512May 7, 2001Aug 2, 2005Sharp Kabushiki KaishaNitride semiconductor light-emitting device and optical apparatus including the sameUS6951695Oct 17, 2002Oct 4, 2005Cree, Inc.High surface quality GaN wafer and method of fabricating sameUS7053413Apr 26, 2004May 30, 2006General Electric CompanyHomoepitaxial gallium-nitride-based light emitting device and method for producingUS7057211Oct 28, 2002Jun 6, 2006Ammono Sp. Zo.ONitride semiconductor laser device and manufacturing method thereofUS7081162Jun 6, 2002Jul 25, 2006Nichia CorporationMethod of manufacturing bulk single crystal of gallium nitrideUS7097707Dec 23, 2002Aug 29, 2006Cree, Inc.GaN boule grown from liquid melt using GaN seed wafersUS7099073Sep 27, 2002Aug 29, 2006Lucent Technologies Inc.Optical frequency-converters based on group III-nitridesUS7132730Oct 25, 2002Nov 7, 2006Ammono Sp. Z.O.O.Bulk nitride mono-crystal including substrate for epitaxyUS7160388May 17, 2002Jan 9, 2007Nichia CorporationProcess and apparatus for obtaining bulk monocrystalline gallium-containing nitrideUS7252712May 17, 2002Aug 7, 2007Ammono Sp. Z O.O.Process and apparatus for obtaining bulk monocrystalline gallium-containing nitrideUS7291544Sep 1, 2004Nov 6, 2007General Electric CompanyHomoepitaxial gallium nitride based photodetector and method of producingUS7314517Dec 11, 2003Jan 1, 2008Ammono Sp. Z.O.O.Process for obtaining bulk mono-crystalline gallium-containing nitrideUS7315599Dec 29, 1999Jan 1, 2008Intel CorporationSkew correction circuitUS7335262Dec 11, 2002Feb 26, 2008Ammono Sp. Z O.O.Apparatus for obtaining a bulk single crystal using supercritical ammoniaUS7364619Apr 17, 2003Apr 29, 2008Ammono. Sp. Zo.O.Process for obtaining of bulk monocrystalline gallium-containing nitrideUS7374615Jun 6, 2002May 20, 2008Ammono.Sp.Zo.OMethod and equipment for manufacturing aluminum nitride bulk single crystalUS7387677Dec 11, 2003Jun 17, 2008Ammono Sp. Z O.O.Substrate for epitaxy and method of preparing the sameUS7410539Dec 11, 2003Aug 12, 2008Ammono Sp. Z O.O.Template type substrate and a method of preparing the sameUS7420261Oct 30, 2006Sep 2, 2008Ammono Sp. Z O.O.Bulk nitride mono-crystal including substrate for epitaxyUS7422633Jun 6, 2002Sep 9, 2008Ammono Sp. Zo. O.Method of forming gallium-containing nitride bulk single crystal on heterogeneous substrateUS20010008656Oct 21, 1997Jul 19, 2001Michael A. TischlerBulk single crystal gallium nitride and method of making sameUS20010015437Jan 25, 2001Aug 23, 2001Hirotatsu IshiiGaN field-effect transistor, inverter device, and production processes thereforUS20010022154Apr 16, 2001Sep 20, 2001Cho Hak DongMethod and apparatus for single crystal gallium nitride (GAN) bulk synthesisUS20010030328Mar 27, 2001Oct 18, 2001Masahiro IshidaNitride semiconductor deviceUS20020011599May 27, 1999Jan 31, 2002Kensaku MotokiGallium nitride single crystal substrate and method of proucing sameUS20020014631Jun 27, 2001Feb 7, 2002Kakuya IwataSemiconductor light emitting deviceUS20020028564Jul 10, 2001Mar 7, 2002Kensaku MotokiMethod of producing a single crystal gallium nitride substrate and single crystal gallium nitride substrateUS20020031153Sep 28, 2001Mar 14, 2002Atsuko NiwaOptical information processing equipment and semiconductor light emitting device suitable thereforUS20020047113Aug 29, 2001Apr 25, 2002Nec CorporationSemiconductor deviceUS20020063258May 25, 1999May 30, 2002Kensaku MotokiGallium nitride-type semiconductor deviceUS20020078881Nov 30, 2001Jun 27, 2002Cuomo Jerome J.Method and apparatus for producing M'''N columns and M'''N materials grown thereonUS20020096674Dec 31, 2001Jul 25, 2002Cho Hak DongNucleation layer growth and lift-up of process for GaN waferUS20020189531May 17, 2002Dec 19, 2002Dwilinski Robert TomaszProcess and apparatus for obtaining bulk monocrystalline gallium-containing nitrideUS20020192507May 17, 2002Dec 19, 2002Dwilinski Robert TomaszBulk monocrystalline gallium nitrideUS20030001238Jun 5, 2002Jan 2, 2003Matsushita Electric Industrial Co., Ltd.GaN-based compound semiconductor EPI-wafer and semiconductor element using the sameUS20030003770Aug 29, 2002Jan 2, 2003Matsushita Electric Industrial Co., Ltd.Method for removing foreign matter, method for forming film, semiconductor device and film forming apparatusUS20030022028Sep 24, 2002Jan 30, 2003Toyoda Gosei Co., Ltd.Group III nitride compound semiconductor device and group III nitride compound semiconductor light-emitting deviceUS20030143771Jan 16, 2003Jul 31, 2003Matsushita Electric Industrial Co., Ltd.Method of fabricating nitride semiconductor, method of fabricating nitride semiconductor device, nitride semiconductor device, semiconductor light emitting device and method of fabricating the sameUS20030209191May 13, 2002Nov 13, 2003Purdy Andrew P.Ammonothermal process for bulk synthesis and growth of cubic GaNUS20040003495Dec 23, 2002Jan 8, 2004Xueping XuGaN boule grown from liquid melt using GaN seed wafersUS20040031978May 19, 2003Feb 19, 2004General Electric CompanyHomoepitaxial gallium-nitride-based light emitting device and method for producingUS20040089221Oct 14, 2003May 13, 2004Dwilinski Robert TomaszBulk monocrystalline gallium nitrideUS20040139912May 17, 2002Jul 22, 2004Robert Tomasz DwilinskiProcess and apparatus for obtaining bulk monocrystalline gallium-containing nitrideUS20040238810Oct 28, 2002Dec 2, 2004Robert DwilinskiNitride semiconductor laser device and manufacturing method thereforUS20040244680Jun 6, 2002Dec 9, 2004Robert DwilinskiMethod of manufacturing bulk single crystal of gallium nitrideUS20040251471Oct 28, 2002Dec 16, 2004Robert DwilinskiLight emitting element structure using nitride bulk single crystal layerUS20040255840Jun 6, 2002Dec 23, 2004Robert DwilinskiMethod for forming gallium-containing nitride bulk single crystal on heterogenous substrateUS20040261692Oct 25, 2002Dec 30, 2004Robert DwilinskiSubstrate for epitaxyUS20050087124Jun 6, 2002Apr 28, 2005Robert DwilinskiMethod and equipment for manufacturing aluminum nitride bulk single crystalUS20050249255Jun 26, 2003Nov 10, 2005Robert DwilinskiNitride semiconductor laser device and a method for improving its performanceUS20060032428Apr 17, 2003Feb 16, 2006Ammono. Sp. Z.O.O.Process for obtaining of bulk monocrystalline gallium-containing nitrideUS20060037530Dec 11, 2003Feb 23, 2006Ammono Sp. Z O.O.Process for obtaining bulk mono-crystalline gallium-containing nitrideUS20060054075Dec 11, 2003Mar 16, 2006Robert DwilinskiSubstrate for epitaxy and method of preparing the sameUS20060054076Dec 13, 2002Mar 16, 2006Ammono Sp. Z O.O.Phosphor single crystal substrate and method for preparing the same, and nitride semiconductor component using the sameUS20060057749Dec 11, 2003Mar 16, 2006Robert DwilinskiTemplate type substrate and a method of preparing the sameUS20060124051Sep 30, 2005Jun 15, 2006Mitsubishi Chemical CorporationZinc oxide single crystalUS20060138431Dec 11, 2002Jun 29, 2006Robert DwilinskiLight emitting device structure having nitride bulk single crystal layerUS20060177362Jan 25, 2005Aug 10, 2006D Evelyn Mark PApparatus for processing materials in supercritical fluids and methods thereofUS20070234946Apr 6, 2007Oct 11, 2007Tadao HashimotoMethod for growing large surface area gallium nitride crystals in supercritical ammonia and lagre surface area gallium nitride crystalsUS20080050855Oct 22, 2007Feb 28, 2008Robert DwilinskiNitride semiconductor laser device and a method for improving its performanceUS20080067523Jun 10, 2005Mar 20, 2008Robert DwilinskiHigh Electron Mobility Transistor (Hemt) Made of Layers of Group XIII Element Nitrides and Manufacturing Method ThereofUS20080102016Oct 25, 2007May 1, 2008The Regents Of The University Of CaliforniaMethod for growing group III-nitride crystals in a mixture of supercritical ammonia and nitrogen, and group III-nitride crystals grown therebyUS20080108162Jan 4, 2008May 8, 2008Ammono Sp.Zo.OLight-Emitting Device Structure Using Nitride Bulk Single Crystal LayerUS20080156254Nov 28, 2005Jul 3, 2008Ammono Sp. Z O.O.Nitride Single Crystal Seeded Growth in Supercritical Ammonia with Alkali Metal IonUS20080303032Jun 10, 2005Dec 11, 2008Robert DwilinskiBulk Mono-Crystalline Gallium-Containing Nitride and Its ApplicationUS20090072352Sep 19, 2008Mar 19, 2009The Regents Of The University Of CaliforniaGallium nitride bulk crystals and their growth methodCN1036414ADec 30, 1988Oct 18, 1989中国科学院物理研究所Method of growing ktp monocrystals by means of modified mineralizing agent and its productCN1065289CJul 22, 1996May 2, 2001中国科学院物理研究所Water heating growth method for preparing adulterated vanadate single crystalCN1260409CJun 6, 2002Jun 21, 2006波兰商艾蒙诺公司Method for obtaining bulk monocrystalline gallium nitrideCN1289867ASep 29, 1999Apr 4, 2001中国科学院物理研究所Hot liquid method for growing monocrystal of gallium nitrideCN1463308AJun 6, 2002Dec 24, 2003波兰商艾蒙诺公司Method for obtaining bulk monocrystalline gallium nitrideEP0711853B1Apr 5, 1995Sep 8, 1999Japan Energy CorporationMethod for growing gallium nitride compound semiconductor crystal, and gallium nitride compound semiconductor deviceEP0716457A2Dec 1, 1995Jun 12, 1996Nichia Chemical Industries, Ltd.Nitride semiconductor light-emitting deviceEP0716457B1Dec 1, 1995Sep 24, 2008Nichia CorporationNitride semiconductor light-emitting deviceEP0949731A2Apr 6, 1999Oct 13, 1999Matsushita Electronics CorporationNitride semiconductor laser deviceEP0973207A2Jul 14, 1999Jan 19, 2000Kabushiki Kaisha ToshibaSemiconductor light emitting deviceEP1088914B1Sep 27, 2000Feb 28, 2007Sumitomo Electric Industries, LimitedMethod of growing single crystal GaN, method of making single crystal GaN substrate and single crystal GaN substrateEP1164210A2Jun 14, 2001Dec 19, 2001Sharp CorporationA method of growing a semiconductor layerEP1164210A3Jun 14, 2001Feb 4, 2004Sharp CorporationA method of growing a semiconductor layerEP1405936A1Jun 6, 2002Apr 7, 2004Ammono SP.ZO.O.Method and equipment for manufacturing aluminum nitride bulk single crystalEP1514958A1Dec 11, 2002Mar 16, 2005Ammono SP.ZO.O.Bulk single crystal production facility employing supercritical ammoniaEP1616981A1Apr 2, 2004Jan 18, 2006Tokyo Denpa Co., Ltd.Zinc oxide single crystalEP1770189A2May 17, 2002Apr 4, 2007Ammono SP.ZO.O.Process and apparatus for obtaining bulk monocrystalline gallium-containing nitrideFR2796657B1 Title not availableGB2326160B Title not availableGB2333521B Title not availableJP4416648B2 * Title not availableJP5183189A Title not availableJP9508093A Title not availableJP9512385A Title not availableJP10084161A Title not availableJP20029392A Title not availableJP200044400A Title not availableJP2000327495A Title not availableJP2001148510A Title not availableJP2001185718A Title not availableJP2001210861A Title not availableJP2001247399A Title not availableJP2002026442A Title not availableJP2002029897A Title not availableJP2002053399A Title not availableJP2002068897A Title not availableJP2002134416A Title not availableJP2002241112A Title not availableJP2002274997A Title not availableJP2003527296A Title not availableJPH11189498A Title not availableJPH11224856A Title not availableJPH11340573A Title not availableJPS6065798A Title not availablePL347918A1 Title not availablePL350375A1 Title not availableWO2095/04845A1 Title not availableWO1994028204A1May 23, 1994Dec 8, 1994Technalum Research, Inc.Filtering flow guide for hydrothermal crystal growthWO1998047170A1Apr 9, 1998Oct 22, 1998Nichia Chemical Industries, Ltd.Method of growing nitride semiconductors, nitride semiconductor substrate and nitride semiconductor deviceWO2001068955A1Mar 12, 2001Sep 20, 2001Advanced Technology Materials, Inc.Iii-v nitride substrate boule and method of making and using the sameWO2002101120A2May 17, 2002Dec 19, 2002Ammono Sp. Zo.OProcess and apparatus for obtaining bulk monocrystalline gallium-containing nitrideWO2002101124A1Jun 6, 2002Dec 19, 2002Ammono Sp.Zo.O.Method and equipment for manufacturing aluminum nitride bulk single crystalWO2003035945A2Oct 25, 2002May 1, 2003Ammono Sp. Zo.O.Substrate for epitaxyWO2003043150A1Oct 28, 2002May 22, 2003Ammono Sp.Zo.O.Light emitting element structure using nitride bulk single crystal layerWO2004004085A2Jun 26, 2003Jan 8, 2004Ammono Sp.Zo.O.Nitride semiconductor laser device and a method for improving its performanceWO2004090202A1Apr 2, 2004Oct 21, 2004Mitsubishi Chemical CorporationZinc oxide single crystalWO2005121415A1Jun 10, 2005Dec 22, 2005Ammono Sp. Z O.O.Bulk mono-crystalline gallium-containing nitride and its applicationWO2008051589A2Oct 25, 2007May 2, 2008The Regents Of The University Of CaliforniaMethod for growing group iii-nitride crystals in a mixture of supercritical ammonia and nitrogen, and group iii-nitride crystals grown therebyWO2008051589A3Oct 25, 2007Jun 12, 2008Univ CaliforniaMethod for growing group iii-nitride crystals in a mixture of supercritical ammonia and nitrogen, and group iii-nitride crystals grown thereby* Cited by examinerNon-Patent CitationsReference1A. Kaschner et al., "Influence of Doping on The Lattice Dynamics of Gallium Nitride", MRS Internet J. Nitride Semicond. Res.4S1, G3.57, 1999.2A. Yoshikawa et al., "Crystal growth of GaN by ammonothermal method", Journal of Crystal Growth 260 (2004), pp. 67-72.3A.P. Purdy "Ammonothermal Synthesis of Cubic Gallium Nitride", Chem. Matter, 1999, 11, pp. 1648-1651.4B. Raghothamachar et al., "Characterization of bulk grown GaN and AlN single crystal materials", Journal of Crystal Growth 287 (2006), pp. 349-353.5Beaumont et al. "Epitaxial Lateral Overgrowth of GaN", Phys. Stat. vol. (b) 227, No. 1, pp. l-43, Germanry, 2001.6C. M. Balkas et al.; Materials Research Society. Symp. Proc. vol. 449, pp. 41-46, 1997. Cited in U.S. Appl. No. 10/147,318.7Canadian Office Action dated Apr. 2, 2009, issued in corresponding Canadian Patent Application No. 2,449,714.8Chinese Office Action dated Dec. 28, 2007, issued in corresponding Chinese Patent Application No. 02802023.5.9Chinese Office Action dated Jul. 18, 2008 (issuing date date), issued in corresponding Chinese Patent Application No. 200580040008.X.10Chinese Office Action dated Jun. 5, 2009 (issuing date), issued in copending Chinese Patent Application No. 200580040008.X.11Chinese Office Action for Application No. 02802023.5 mailed Apr. 13, 2007.12D. Ketchum et al.; Journal of Crystal Growth 222, pp. 431-434, 2001. Cited in U.S. Appl No. 10/147,319.13D. Peters, "Ammonothermal Synthesis of Aluminium Nitride", Journal of Crystal Growth 104, 1990, pp. 411-418.14Dwilinski, U.S. Appl. No. 10/538,407, filed Jun. 10, 2005, Office Action dated Apr. 2, 2007.15Dwilinski, U.S. Appl. No. 10/538,654, filed Jun. 10, 2005, Office Action dated Oct. 16, 2007.16Editor Keshra Sangwal, "Elementary Crystal Growth", Lublin 1994, p. 331.17English translation of Preliminary Notice of Rejection of the IPO, dated Aug. 30, 2004.18English translation of Preliminary Notice of Rejection of the IPO, dated Feb. 2, 2004.19English translation of Substrate for III-V group nitride semiconductor.20European Communication dated Oct. 21, 2009, issued in corresponding European Patent Application No. 02762734.8.21European Search Report dated Jul. 2, 2009, issued in corresponding European Patent Application No. 03778841.22European Search Report dated Jul. 6, 2009, issued in corresponding European Patent Application No. 03733682.23European Search Report dated Sep. 12, 2008, issued in corresponding European Patent Application No. 02 78 8783.24H. Yamane et al.; Japanese Journal of Applied Physics, vol. 37, No. 6A, Part. I, pp. 3436-3440, XP001110371, Jun. 1998. Cited in the ISR of PCT/PL02/00077.25Hisanori Yamane et al., "Morphology and characterization of GaN single crystals grown in a Na flux", Journal of crystal growth, vol. 186, pp. 8-12, 1998.26Hisanori Yamane et al., "Na Flux Growth of GaN Single Crystals", Journal of the Japanese Association for Crystal Growth, vol. 25, No. 4, pp. 14-18, 1998.27Hydrothermal Synthesis Handbook (Gihodo press 1997) Second edition of application edition 1 Chapter 1, Single Crystal Growth; pp. 245-255.28I. Akasaki et al., "Growth and Properties of Single Crystalline GaN Films by Hydride Vapor Phase Epitaxy", Crystal Properties and Preparation, vol. 32-34, 1991, pp. 154-157.29I. Grzegory. Institute of Physics Publishing, Matter 13, pp. 6875-6892, 2001.30Inoue et al., "Growth of bulk GaN single crystals by the pressure-controlled solution growth method", Journal of Crystal Growth 229 (2001), Elsevier Science B.V., pp. 35-40.31International Preliminary Examination Reports of PCT/JP02/12969 and PCTT/JP02/11136.32International Search Report dated Apr. 29, 2004, issued in corresponding PCT/JP03/15906.33International Search Report dated Apr. 4, 2006, issued in corresponding PCT/JP2005/022396.34International Search Report dated Sep. 14, 2005, issued in corresponding PCT/JP2005/011019.35International Search Report of PCT/IB02/04185.36International Search Report of PCT/IB02/04441.37International Search Report of PCT/JP02/11136.38International Search Report of PCT/JP02/12956.39International Search Report of PCT/JP02/13079.40International Search Report of PCT/PL02/00077.41Japanese Notification dated Mar. 14, 2006, issued in related Japanese Patent Application No. 2003-503867.42Japanese Office Action dated Dec. 15, 2009 (Dispatch Date), issued in corresponding Japanese Patent Application No. 2004-558480.43Japanese Office Action dated Dec. 16, 2008 (mailing date), issued in corresponding Japanese Patent Application No. 2004-505416.44Japanese Office Action dated Jan. 5, 2010 (Dispatch Date), issued in corresponding Japanese Patent Application No. 2003-538438.45Japanese Office Action dated Jan. 6, 2009 (mailing date), issued in corresponding Japanese Patent Application No. 2004-506101.46Japanese Office Action dated Jul. 28, 2009 (dispatch date), issued in corresponding Japanese Patent Application No. 2003-538438.47Japanese Office Action dated May 12, 2009 (mailing date), issued in corresponding Japanese Patent Application No. 2003-544869.48Japanese Office Action dated May 7, 2009 (mailing date), issued in corresponding Japanese Patent Application No. 2004-506141.49Japanese Office Action dated Nov. 17, 2009 (Dispatch Date), issued in corresponding Japanese Patent Application No. 2004-558482.50Japanese Office Action dated Nov. 4, 2009 (Dispatch Date), issued in corresponding Japanese Patent Application No. 2004-506101.51Jin-Kuo Ho et al. "Low-resistance ohmic contacts to p-type GaN achieved by the oxidation of Ni/Au films", Journal Applied Physics, Oct. 1999, pp. 4491-4497, vol. 86, No. 8, American Institute of Physics.52K. Pakula et al.; Acta Physica Polonica A, vol. 88, No. 5, pp. 861-864. 1995. Cited in the international search report.53K. Yanagisawa et al.; J. Cryst. Growth, Hydrothermal Single Crystal Growth of Calcite in Ammonium Acetate Solution; vol. 163, 1996, pp. 285-294.54K. Yanagisawa et al.; J. Cryst. Growth, Improvement of Quality of Hydrothermally Grown Calcite Single Crystals; vol. 229, 2001, pp. 440-444.55Kato et al., "MOVPE Growth of GaN on off-angle sapphire substrate", IEICE Technical Report ED88-22~30, May 28, 1988 and its English Abstract.56Kato et al., "MOVPE Growth of GaN on off-angle sapphire substrate", IEICE Technical Report ED88-22˜30, May 28, 1988 and its English Abstract.57Kelly et al., "Optical pattering of GaN films", Applied Pysics Letters vol. 69, No. 12, Sep. 16, 1996, American Institute of Physics, pp. 1749-1751.58Kensuke Motoki et al., "Preparation of Large Freestanding GaN Substrates by Hydride Vapor Phase Epitaxy Using GaAs as a Starting Substrate", Japanese J. Applied Physics, 40, Part 2, No. 2B, 2001, pp. L140-L143.59Kolis et al., "Materials Chemistry and Bulk Crystal Growth of Group III Nitrides in Supercritical Ammonia", Mat. Res. Soc. Symp. Proc. vol. 495, 1998 Materials Research Society, pp. 367-372.60Liu et al. "Substrates for gallium nitride epitaxy", Materials Science and Engineering R 37 (2002), Elsevier Science B.V., pp. 61-127.61M. Aoki et al.; Journal of Crystal Growth 218, pp. 7-12, 2000. Cited in the ISR of PCT/PL02/00077.62M. Palczewska et al.; MRS Internet Journal, Res. 3, 45. 1998.63M. Yano et al.; Japanese Journal of Applied Physics, vol. 38, No. 10A, Part 2, pp. L1121-L113, XP000891127. Oct. 1999. Cited in the ISR of PCT/PL02/00077.64Melnik et al.; Materials Research Society. Symp. Proc. vol. 482, pp. 269-274 -1998. Cited in U.S. Appl. No. 10/147,318.65Mitsuko Fukuda, "Optical Semiconductor Devices", Wiley Series in Microwave and Optical Engineering, Ed. K. Chang, John Wiley & Sons, New York 1998, pp. 7.66N. Ikornikova "Hydrothermal Synthesis of Crystals in Chloride Systems", ed. Izd. Nauka, Moscow, 1975, pp. 124-133.67N. Sakagami et al.; Journal of the Ceramic Association, "Growth Kinetics and Morphology of ZnO Single Crystal Grown under Hydrothermal Conditions"; vol. 82, 1974, pp. 405-413.68Naotaka Kuroda et al., "Precise control of pn-junction profiles for GaN-based LD structures using GaN substrates with low dislocation densities", Journal of Crystal Growth, vol. 189/190, 1998, pp. 551-555.69Notification dated Jan. 15, 2007 of the corresponding Polish application No. P-347918.70Notification of Reason for Refusal dated Feb. 9, 2010 issued in Japanese Patent Application No. 2004-517422.71Notification of Reason for Refusal dated Jan. 26, 2010, issued in Japanese Patent Application No. 2004-517425.72Notification, Japanese Patent Application No. 2003-503864, dispatched on Sep. 27, 2005.73O. Brandt et al., "Critical issues for the growth of high-quality (A1, Ga) N/GaN and GaN/ (In, Ga) N heterostructures on SiC (0001) by molecular-beam epitaxy", Applied Physics Letters, vol. 75, No. 25, pp. 4019-4021, Dec. 20, 1999.74O. Oda et al.; Phys. Stat. sol. (a) 1'80, pp. 51-58. 2000.75Office Action date Oct. 4, 2005 issued in co pending U.S. Appl. No. 10/479,858.76Office Action dated Apr. 20, 2006, issued in related U.S. Appl. No. 10/493,747.77Office Action dated Aug. 8, 2006 issued in corresponding Japanese patent application No. 2003-539145.78Office Action dated Dec. 28, 2007, issued in corresponding Chinese Patent Application No. 02802023.5.79Office Action dated Jan. 25, 2010 of U.S. Appl. No. 11/791,716.80Office Action dated Jul. 18, 2006 issued in corresponding Japanese patent application No. 2003-544869.81Office Action dated Mar. 21, 2007 of the corresponding U.S. Appl. No. 10/479,857.82Office Action dated Mar. 24, 2006, issued in related U.S. Appl. No. 10/493,594.83Office Action dated Mar. 3, 2006 issued in corresponding Chinese Patent Application No. 02821230.4.84Office Action dated Nov. 4, 2005 issued in co pending U.S. Appl. No. 10/493,747.85Office Action dated Oct. 19, 2005 issued in co pending U.S. Appl. No. 10/147,319.86Office Action dated Oct. 27, 2008, U.S. Appl. No. 10/493,594.87Office Action dated Oct. 29, 2008, U.S. Appl. No. 10/514,429.88Office Action dated Sep. 7, 2006 issued in related U.S. Appl. No. 10/479,857.89Office Action of U.S. Appl. No. 12/213,212 from US. Patent Office dated Jul. 30, 2010.90P. Waltereit et al., "Nitride semiconductors free of electrostatic fields for efficient white light-emitting diodes", NATURE, vol. 406, pp. 865-868, Aug. 24, 2000.91Porowski et al., "Prospects for hight-pressure crystal growth of III-V nitrides", Inst. Phys. Conf. Ser. No. 137, Chaper 4, 1993, pp. 369-372.92Provision of Relevant Information on Prior Arts dated Dec. 24, 2008 (dispatch date), filed in corresponding Japanese Patent Application No. 2004-558483.93Q.-S. Chen et al., "Effects of baffle design on fluid flow and heat transfer in ammonothermal growth of nitrides", Journal of Crystal Growth 266 (2004), pp. 271-277.94Q.-S. Chen et al., "Modeling of ammonothermal growth of nitrides", Journal of Crystal Growth 258 (2003), pp. 181-187.95R. A. Laudise; What Is Materials Chemistry?, Materials for nonlinear optics: Chemical Perspectives (American Chemical Society 1991); pp. 410-433.96R. Dwilinski et al.; Acta Physica Polonica A, vol. 90, No. 4, pp. 763-766. 1996. Cited in the international search report.97R. Dwilinski et al.; Diamond and Related Materials, vol. 7, No. 9, pp. 1348-1350. 1998. Cited in the ISR of PCT/JP02/12956.98R. Dwilinski et al.; Materials Science and Engineering B50, pp. 46-49, 1997. Cited in the ISR of PCT/IB02/04185.99R. Dwilinski et al.; MRS Internet Journal Nitride Semiconductor Research No. XP-002235467. The Material Research Society, vol. 3, No. 25, 1998. Cited in the ISR of PCT/PL02/00077.100S. Hirano et al.; Hydrothermal Synthesis of Gallium Orthophosphate Crystals, Bull. Chem. Soc. Jpn., 62; pp. 275-278, 1989.101S. Hirano et al.; J. Materials Science, Growth of Gallium Orthophosphate Single Crystals in Acidic Hydrothermal Solutions; vol. 26, 1991, pp. 2805-2808.102S. M. Sze, "Modern Semiconductor Device Physics", A Wiley-Interscience Publication, John Wiley and Sons, New York 1998, pp. 539-540.103S. Porowski , "High Pressure Growth of GaN-New Prospects for Blue Lasers", Journal of Crystal Growth 166 (1996), pp. 583-589.104S. Porowski; Journal of Crystal Growth, 189/190, pp. 153-158, 1998. Cited in U.S. Appl. No. 10/147,318.105S.T. Kim et al., "Preparation and properties of free-standing HVPE grown GaN substrates", Journal of Crystal Growth, vol. 194, 1998, pp. 37-42.106Sakai et al., "Defect structure in selectively grown GaN films with low threading dislocation density", Appl. Phys. Lett 71 (16), Oct. 20, 1997, pp. 2259-2261.107Search Report dated Aug. 22, 2007, issued in corresponding European Patent Application No. 02 77 5396.108Search Report dated Jan. 15, 2007 of the corresponding Polish application No. P-347918.109Song et al., "Bulk GaN single crystals: growth conditions by flux method", Journal of Crystal Growth 247 (2003) Elsevier Science B.V., pp. 275-278.110T. Hashimoto et al., "Growth of gallium nitride via fluid transport in supercritical ammonia", Journal of Crystal Growth 275 (2005), pp. e525-e530.111T. Penkala, "Zarys Krystalografii", PWN, Warszawa 1972, p. 349.112T. Sekiguchi et al.; J. Cryst. Growth, "Hydrothermal Growth of ZnO Single Crystals and their Optical Characterization"; vol. 214/215, 2000, pp. 72-76.113T.L. Chu et al., "Crystal Growth and Characterization of Gallium Nitride", J. Electrochem. Soc. Solid-State Science and Tecnology, 121-1, 1974, pp. 159-162.114U.S. Appl. No. 10/493,746, filed Apr. 26, 2004, Dwilinski et al.115U.S. Office Action dated Apr. 28, 2009, issued in corresponding U.S. Appl. No. 11/969,735.116U.S. Office Action dated Dec. 4, 2009, issued in corresponding U.S. Appl. No. 11/969,735.117US Office Action dated Jun. 1, 2009 (mailing date), issued in copending U.S. Appl. No. 11/791,716.118Wong et al., "Fabrication of thin-film InGaN light-emitting diode membrances by laser lift-off", Applied Pysics Letters, vol. 75, No. 10, 1999 American Institute of Physics, pp. 1360-1362.119Xiang-jun Mao et al.; SPIE Photonics Taiwan Conference Proceeding, pp. 1-12, Jul. 2000. Cited in U.S. Appl. No. 10/147,319.120Y.C. Lan et al, "Syntheses and Structure of Nanocrystalline Gallium Nitride Obtained from Ammonothermal Method Using Lithium Metal as Mineralizator", Materials Research Bulletin, 35(2000), pp. 2325-2330.121Yano et al., "Growth of nitride crystals, BN, AlN and GaN by using a Na flux", Diamond and Related Materials (2000), V. 9, No. 3-6, pp. 512-515.Classifications U.S. Classification438/46, 257/E21.123, 257/E33.025, 438/13International ClassificationH01L33/38, H01L33/00, H01L21/00, H01L33/16Cooperative ClassificationH01L33/007, H01S5/2206, H01L33/16, H01S5/2232, H01S5/3216, H01S5/34333, H01L33/38, H01S5/2231, B82Y20/00, H01S2304/00, H01S5/22European ClassificationH01S5/343G, H01L33/00G3B2, B82Y20/00Legal EventsDateCodeEventDescriptionJun 18, 2014FPAYFee paymentYear of fee payment: 4RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services