Patents Assigned to Crystal Photonics, Incorporated
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Patent number: 9658344Abstract: A radiation detector, such as for a PET scanner, may include an array of scintillator crystals, with each scintillator crystal having a polished end, a roughened end opposite the polished end, and polished sides extending between the polished end and the roughened end. The detector may also include a specular reflector layer between adjacent polished sides of adjacent ones of the array of scintillator crystals, and a diffusive reflector layer adjacent the roughened ends of the array of scintillator crystals. The detector may further include at least one photodetector adjacent the polished ends of the array of scintillator crystals.Type: GrantFiled: November 4, 2015Date of Patent: May 23, 2017Assignee: CRYSTAL PHOTONICS, INCORPORATEDInventors: Bruce Chai, Xiao-mei Pan, Bao-hui Zhou
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Patent number: 7972438Abstract: This invention is related to material for use as an ultraviolet (UV) optical element and particularly for use as a 193 nm immersion lens element. The material for use as a UV optical element includes a Lithium Magnesium Aluminate (LMAO) body. The specific compound for this application is the disordered lithium magnesium spinel, having the general composition of LixMg2(1?x)Al4+xO8 where x=0 to 1 as the high-index UV transparent material for immersion lithography. The LMAO body may include a disordered spinel, such as, for example, a single crystal that may be cubic in symmetry, optically isotropic, and having cation disorder within the structure to reduce the intrinsic birefringence (IBR). The LMAO body has certain desired material properties and may be readily made in relatively large sizes suitable for use as the UV optical element for photolithography.Type: GrantFiled: August 29, 2007Date of Patent: July 5, 2011Assignee: Crystal Photonics, IncorporatedInventors: Yi-Ting Fei, Shen Jen, Bruce Chai
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Patent number: 7576372Abstract: A method for making a free-standing, single crystal, aluminum gallium nitride (AlGaN) wafer includes forming a single crystal AlGaN layer directly on a single crystal LiAlO2 substrate using an aluminum halide reactant gas, a gallium halide reactant gas, and removing the single crystal LiAlO2 substrate from the single crystal AlGaN layer to make the free-standing, single crystal AlGaN wafer. Forming the single crystal AlGaN layer may comprise depositing AlGaN by vapor phase epitaxy (VPE) using aluminum and gallium halide reactant gases and a nitrogen-containing reactant gas. The growth of the AlGaN layer using VPE provides commercially acceptable rapid growth rates. In addition, the AlGaN layer can be devoid of carbon throughout. Because the AlGaN layer produced is high quality single crystal, it may have a defect density of less than about 107cm?2.Type: GrantFiled: January 26, 2007Date of Patent: August 18, 2009Assignee: Crystal Photonics, IncorporatedInventors: Herbert Paul Maruska, John Joseph Gallagher, Mitch M. C. Chou, David W. Hill
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Patent number: 7397034Abstract: A method for enhancing the light yield of a doped scintillation crystal may include a reducing step if the crystal includes a dopant, such as cerium in a first oxidation state, such as the 4+ state. The scintillation crystal may include a rare earth silicate. The reducing may include heating in an oxygen-free ambient. The reducing may be used after an oxygen vacancy filling step that causes at least some of the dopant to increase in its oxidation state.Type: GrantFiled: September 19, 2005Date of Patent: July 8, 2008Assignee: Crystal Photonics, IncorporatedInventors: Bruce H. T. Chai, David Y. Chai, Randall A. Lux
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Publication number: 20080055715Abstract: This invention is related to material for use as an ultraviolet (UV) optical element and particularly for use as a 193 nm immersion lens element. The material for use as a UV optical element includes a Lithium Magnesium Aluminate (LMAO) body. The specific compound for this application is the disordered lithium magnesium spinel, having the general composition of LixMg2(1-x)Al4+xO8 where x=0 to 1 as the high-index UV transparent material for immersion lithography. The LMAO body may include a disordered spinel, such as, for example, a single crystal that may be cubic in symmetry, optically isotropic, and having cation disorder within the structure to reduce the intrinsic birefringence (IBR). The LMAO body has certain desired material properties and may be readily made in relatively large sizes suitable for use as the UV optical element for photolithography.Type: ApplicationFiled: August 29, 2007Publication date: March 6, 2008Applicant: Crystal Photonics, IncorporatedInventors: Yi-Ting Fei, Shen Jen, Bruce Chai
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Patent number: 7169227Abstract: A method for making a free-standing, single crystal, aluminum gallium nitride (AlGaN) wafer includes forming a single crystal AlGaN layer directly on a single crystal LiAlO2 substrate using an aluminum halide reactant gas, a gallium halide reactant gas, and removing the single crystal LiAlO2 substrate from the single crystal AlGaN layer to make the free-standing, single crystal AlGaN wafer. Forming the single crystal AlGaN layer may comprise depositing AlGaN by vapor phase epitaxy (VPE) using aluminum and gallium halide reactant gases and a nitrogen-containing reactant gas. The growth of the AlGaN layer using VPE provides commercially acceptable rapid growth rates. In addition, the AlGaN layer can be devoid of carbon throughout. Because the AlGaN layer produced is high quality single crystal, it may have a defect density of less than about 107 cm?2.Type: GrantFiled: March 25, 2003Date of Patent: January 30, 2007Assignee: Crystal Photonics, IncorporatedInventors: Herbert Paul Maruska, John Joseph Gallagher, Mitch M. C. Chou, David W. Hill
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Patent number: 7166845Abstract: A method for enhancing the light yield of a single crystal of cerium doped lutetium yttrium orthosilicate (LYSO) in response to irradiation with high energy radiation includes diffusing oxygen into the crystal by heating the crystal for a period of time in an ambient containing oxygen. This process of thermal oxygenation of the crystal effectively supplies oxygen to fill at least some of the oxygen vacancies in the body of monocrystalline LYSO. A scintillation detector comprises a monocrystalline body of LYSO enhanced by oxygen diffusion into the crystal.Type: GrantFiled: January 9, 2004Date of Patent: January 23, 2007Assignee: Crystal Photonics, IncorporatedInventor: Bruce Chai
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Patent number: 7151261Abstract: A method for enhancing the light yield of a single crystal of cerium doped lutetium orthosilicate (LSO) in response to irradiation with high energy radiation includes diffusing oxygen into the crystal by heating the crystal for a period of time in an ambient containing oxygen. This process of thermal oxygenation of the crystal effectively supplies oxygen to fill at least some of the oxygen vacancies in the body of monocrystalline LSO. A scintillation detector comprises a monocrystalline body of LSO enhanced by oxygen diffusion into the crystal.Type: GrantFiled: January 9, 2004Date of Patent: December 19, 2006Assignee: Crystal Photonics, IncorporatedInventor: Bruce Chai
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Patent number: 7033858Abstract: A method is for making at least one semiconductor device including providing a sacrificial growth substrate of Lithium Aluminate (LiAlO2); forming at least one semiconductor layer including a Group III nitride adjacent the sacrificial growth substrate; attaching a mounting substrate adjacent the at least one semiconductor layer opposite the sacrificial growth substrate; and removing the sacrificial growth substrate. The method may further include adding at least one contact onto a surface of the at least one semiconductor layer opposite the mounting substrate, and dividing the mounting substrate and at least one semiconductor layer into a plurality of individual semiconductor devices. To make the final devices, the method may further include bonding the mounting substrate of each individual semiconductor device to a heat sink. The step of removing the sacrificial substrate may include wet etching the sacrificial growth substrate.Type: GrantFiled: March 18, 2004Date of Patent: April 25, 2006Assignee: Crystal Photonics, IncorporatedInventors: Bruce H. T. Chai, John Joseph Gallagher, David Wayne Hill
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Publication number: 20060011845Abstract: A method for enhancing the light yield of a doped scintillation crystal may include a reducing step if the crystal includes a dopant, such as cerium in a first oxidation state, such as the 4+ state. The scintillation crystal may include a rare earth silicate. The reducing may include heating in an oxygen-free ambient. The reducing may be used after an oxygen vacancy filling step that causes at least some of the dopant to increase in its oxidation state.Type: ApplicationFiled: September 19, 2005Publication date: January 19, 2006Applicant: Crystal Photonics, IncorporatedInventors: Bruce Chai, David Chai, Randall Lux
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Publication number: 20040209402Abstract: A method is for making at least one semiconductor device including providing a sacrificial growth substrate of Lithium Aluminate (LiAlO2); forming at least one semiconductor layer including a Group III nitride adjacent the sacrificial growth substrate; attaching a mounting substrate adjacent the at least one semiconductor layer opposite the sacrificial growth substrate; and removing the sacrificial growth substrate. The method may further include adding at least one contact onto a surface of the at least one semiconductor layer opposite the mounting substrate, and dividing the mounting substrate and at least one semiconductor layer into a plurality of individual semiconductor devices. To make the final devices, the method may further include bonding the mounting substrate of each individual semiconductor device to a heat sink. The step of removing the sacrificial substrate may include wet etching the sacrificial growth substrate.Type: ApplicationFiled: March 18, 2004Publication date: October 21, 2004Applicant: CRYSTAL PHOTONICS, INCORPORATEDInventors: Bruce H.T. Chai, John Joseph Gallagher, David Wayne Hill
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Patent number: 6648966Abstract: A method for making a free-standing, single crystal, gallium nitride (GaN) wafer includes forming a single crystal GaN layer directly on a single crystal LiAlO2 substrate using a gallium halide reactant gas, and removing the single crystal LiAlO2 substrate from the single crystal GaN layer to make the free-standing, single crystal GaN wafer. Forming the single crystal GaN layer may comprise depositing GaN by vapor phase epitaxy (VPE) using the gallium halide reactant gas and a nitrogen-containing reactant gas. Because gallium halide is used as a reactant gas rather than a metal organic reactant such as trimethygallium (TMG), the growth of the GaN layer can be performed using VPE which provides commercially acceptable rapid growth rates. In addition, the GaN layer is also devoid of carbon throughout. Because the GaN layer produced is high quality single crystal, it may have a defect density of less than about 107 cm−2.Type: GrantFiled: August 1, 2001Date of Patent: November 18, 2003Assignee: Crystal Photonics, IncorporatedInventors: Herbert Paul Maruska, John Joseph Gallagher, Mitch M. C. Chou
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Publication number: 20030183158Abstract: A method for making a free-standing, single crystal, aluminum gallium nitride (AlGaN) wafer includes forming a single crystal AlGaN layer directly on a single crystal LiAlO2 substrate using an aluminum halide reactant gas, a gallium halide reactant gas, and removing the single crystal LiAlO2 substrate from the single crystal AlGaN layer to make the free-standing, single crystal AlGaN wafer. Forming the single crystal AlGaN layer may comprise depositing AlGaN by vapor phase epitaxy (VPE) using aluminum and gallium halide reactant gases and a nitrogen-containing reactant gas. The growth of the AlGaN layer using VPE provides commercially acceptable rapid growth rates. In addition, the AlGaN layer can be devoid of carbon throughout. Because the AlGaN layer produced is high quality single crystal, it may have a defect density of less than about 107 cm−2.Type: ApplicationFiled: March 25, 2003Publication date: October 2, 2003Applicant: Crystal Photonics, IncorporatedInventors: Herbert Paul Maruska, John Joseph Gallagher, Mitch M.C. Chou, David W. Hill
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Publication number: 20030024472Abstract: A method for making a free-standing, single crystal, gallium nitride (GaN) wafer includes forming a single crystal GaN layer directly on a single crystal LiAlO2 substrate using a gallium halide reactant gas, and removing the single crystal LiAlO2 substrate from the single crystal GaN layer to make the free-standing, single crystal GaN wafer. Forming the single crystal GaN layer may comprise depositing GaN by vapor phase epitaxy (VPE) using the gallium halide reactant gas and a nitrogen-containing reactant gas. Because gallium halide is used as a reactant gas rather than a metal organic reactant such as trimethygallium (TMG), the growth of the GaN layer can be performed using VPE which provides commercially acceptable rapid growth rates. In addition, the GaN layer is also devoid of carbon throughout. Because the GaN layer produced is high quality single crystal, it may have a defect density of less than about 107 cm−2.Type: ApplicationFiled: August 1, 2001Publication date: February 6, 2003Applicant: CRYSTAL PHOTONICS, INCORPORATEDInventors: Herbert Paul Maruska, John Joseph Gallagher, Mitch M.C. Chou
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Patent number: 6455986Abstract: An electronic device includes a piezoelectric layer formed of an ordered Langasite structure compound having the formula A3BC3D2E14 wherein A is strontium, B is niobium, C is gallium, D is silicon, and E is oxygen. At least one electrode is connected to the piezoelectric layer and may be configured to define a device, such as a SAW resonator or filter, or a BAW resonator or filter. The ordered Langasite structure compound may have a substantially perfectly ordered structure.Type: GrantFiled: May 3, 2001Date of Patent: September 24, 2002Assignee: Crystal Photonics, IncorporatedInventors: Bruce H. T. Chai, Mitch M. C. Chou, Haihong Qiu, Shen Jen
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Patent number: 6424081Abstract: An electronic device includes a piezoelectric layer formed of an ordered Langasite structure compound having the formula A3BC3D2E14, wherein A is calcium, B is niobium or tantalum, C is gallium, D is silicon, and E is oxygen. At least one electrode is connected to the piezoelectric layer and may be configured to define a device, such as a SAW resonator or filter, or a BAW resonator or filter. The ordered Langasite structure compound may have a substantially perfectly ordered structure.Type: GrantFiled: May 3, 2001Date of Patent: July 23, 2002Assignee: Crystal Photonics, IncorporatedInventors: Bruce H. T. Chai, Mitch M. C. Chou, Haihong Qiu, Shen Jen
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Publication number: 20020027397Abstract: An electronic device includes a piezoelectric layer formed of an ordered Langasite structure compound having the formula A3BC3D2E14, wherein A is calcium, B is niobium or tantalum, C is gallium, D is silicon, and E is oxygen. At least one electrode is connected to the piezoelectric layer and may be configured to define a device, such as a SAW resonator or filter, or a BAW resonator or filter. The ordered Langasite structure compound may have a substantially perfectly ordered structure.Type: ApplicationFiled: May 3, 2001Publication date: March 7, 2002Applicant: Crystal Photonics, IncorporatedInventors: Bruce H.T. Chai, Mitch M.C. Chou, Haihong Qiu, Shen Jen
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Publication number: 20020021193Abstract: An electronic filter includes a piezoelectric layer formed of an ordered Langasite structure compound having the formula A3BC3D2E14, wherein A is strontium, B is tantalum, C is gallium, D is silicon, and E is oxygen. A plurality of pairs of electrodes are connected to and cooperate with the piezoelectric layer to define a SAW or BAW filter, for example. The ordered Langasite structure compound may have a substantially perfectly ordered structure.Type: ApplicationFiled: May 3, 2001Publication date: February 21, 2002Applicant: Crystal Photonics, IncorporatedInventors: Bruce H.T. Chai, Mitch M.C. Chou, Haihong Qiu, Shen Jen
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Publication number: 20020015452Abstract: An electronic device includes a piezoelectric layer formed of an ordered Langasite structure compound having the formula A3BC3D2E14 wherein A is strontium, B is niobium, C is gallium, D is silicon, and E is oxygen. At least one electrode is connected to the piezoelectric layer and may be configured to define a device, such as a SAW resonator or filter, or a BAW resonator or filter. The ordered Langasite structure compound may have a substantially perfectly ordered structure.Type: ApplicationFiled: May 3, 2001Publication date: February 7, 2002Applicant: Crystal Photonics, IncorporatedInventors: Bruce H.T. Chai, Mitch M.C. Chou, Haihong Qiu, Shen Jen