Patent classifications
C30B33/00
Method of acquiring sample for evaluation of SiC single crystal
A method of acquiring a sample for evaluation of a SiC single crystal, comprising: a step of cutting a SiC ingot in a radial direction at a thickness position, which is located in a range from a curved surface which forms a distal end surface in a crystal growth direction to a seed crystal, to obtain a head member which includes the curved surface, wherein the SiC ingot used in the step is a SiC ingot in which SiC thereof is crystal-grown from a seed crystal along a c axis direction; and a step of polishing a silicon surface of the head member to obtain a sample for evaluation.
METHOD OF MANUFACTURING SILICON CARBIDE SUBSTRATE, SILICON CARBIDE SINGLE-CRYSTAL SUBSTRATE AND SILICON CARBIDE SEMICONDUCTOR DEVICE
A method of manufacturing a silicon carbide semiconductor device includes the following steps. In a silicon carbide substrate including a silicon carbide single-crystal substrate and a silicon carbide epitaxial film provided on the silicon carbide single-crystal substrate, a reference mark serving as a reference of two dimensional position coordinates is formed. After forming the reference mark, at least one of polishing or cleaning is performed on a reference mark formation surface of the silicon carbide substrate. Position coordinates of a defect present in the silicon carbide substrate are specified based on the reference mark. A device active region is formed in the silicon carbide substrate. Position coordinates of the device active region are specified based on the reference mark. A pass/fail judgement of the device active region is made by associating the position coordinates of the defect with the position of the device active region.
Crystal Structure Orientation in Semiconductor Semi-Finished Products and Semiconductor Substrates for Fissure Reduction and Method of Setting Same
Crystal structure orientation in semiconductor semi-finished products and semiconductor substrates for fissure reduction and method of setting same The present invention provides monocrystalline semiconductor semi-finished product and substrates having a predetermined orientation of its crystal structure relative to a central axis and a at least partially curved lateral surface of the semi-finished product or substrate that reduces or even eliminates the occurrence of cracks during mechanical processing, and a method of producing such semiconductor semi-finished products and/or substrates. In the predetermined orientation, a first crystallographic axis perpendicular to a set of first cleavage planes makes a first tilt angle with a plane transverse to the central axis, and a second crystallographic axis perpendicular to a set of second cleavage planes and to the first crystallographic axis makes a second tilt angle with said plane transverse to the central axis so that each set of parallel cleavage planes that are symmetrically equivalent to either the first or second cleavage planes are inclined relative to the central axis.
Crystal Structure Orientation in Semiconductor Semi-Finished Products and Semiconductor Substrates for Fissure Reduction and Method of Setting Same
Crystal structure orientation in semiconductor semi-finished products and semiconductor substrates for fissure reduction and method of setting same The present invention provides monocrystalline semiconductor semi-finished product and substrates having a predetermined orientation of its crystal structure relative to a central axis and a at least partially curved lateral surface of the semi-finished product or substrate that reduces or even eliminates the occurrence of cracks during mechanical processing, and a method of producing such semiconductor semi-finished products and/or substrates. In the predetermined orientation, a first crystallographic axis perpendicular to a set of first cleavage planes makes a first tilt angle with a plane transverse to the central axis, and a second crystallographic axis perpendicular to a set of second cleavage planes and to the first crystallographic axis makes a second tilt angle with said plane transverse to the central axis so that each set of parallel cleavage planes that are symmetrically equivalent to either the first or second cleavage planes are inclined relative to the central axis.
Single crystal synthetic diamond material
Single crystal CVD diamond material comprising a total nitrogen concentration of at least 5 ppm and a neutral single substitutional nitrogen. N.sub.s.sup.0, to total single substitutional nitrogen, N.sub.s, ratio of at least 0.7. Such a diamond is observed to have a relatively low amount of brown colouration despite the relatively high concentration of nitrogen A method of making the single crystal diamond is also disclosed, the method including growing the CVD diamond in process gases comprising 60 to 200 ppm nitrogen, in addition to a carbon-containing gas, and hydrogen, wherein the ratio of carbon atoms in the carbon-containing gas to hydrogen atoms in the hydrogen gas is 0.5 to 1.5%.
Single crystal synthetic diamond material
Single crystal CVD diamond material comprising a total nitrogen concentration of at least 5 ppm and a neutral single substitutional nitrogen. N.sub.s.sup.0, to total single substitutional nitrogen, N.sub.s, ratio of at least 0.7. Such a diamond is observed to have a relatively low amount of brown colouration despite the relatively high concentration of nitrogen A method of making the single crystal diamond is also disclosed, the method including growing the CVD diamond in process gases comprising 60 to 200 ppm nitrogen, in addition to a carbon-containing gas, and hydrogen, wherein the ratio of carbon atoms in the carbon-containing gas to hydrogen atoms in the hydrogen gas is 0.5 to 1.5%.
METHODS FOR MANUFACTURING SILICON CARBIDE SINGLE CRYSTAL INGOT AND SILICON CARBIDE SINGLE CRYSTAL WAFER
A raw material gas is supplied to a space in which a silicon carbide seed crystal is placed. A silicon carbide single crystal is grown on the seed crystal by keeping a monosilane partial pressure at 4 kPa or more and heating the space to a temperature of 2400° C. to 2700° C. The temperature of the space and supply of the raw material gas are controlled such that a temperature gradient of a growth crystal surface of the silicon carbide single crystal in a radial direction is 0.1° C./mm or less, and a radius of curvature of the growth crystal surface is 4.5 m or more, thereby producing a silicon carbide single crystal ingot having a growth length of 3 mm or more and an internal stress of 10 MPa or less. The ingot is then cut into a silicon carbide single crystal wafer.
METHODS FOR MANUFACTURING SILICON CARBIDE SINGLE CRYSTAL INGOT AND SILICON CARBIDE SINGLE CRYSTAL WAFER
A raw material gas is supplied to a space in which a silicon carbide seed crystal is placed. A silicon carbide single crystal is grown on the seed crystal by keeping a monosilane partial pressure at 4 kPa or more and heating the space to a temperature of 2400° C. to 2700° C. The temperature of the space and supply of the raw material gas are controlled such that a temperature gradient of a growth crystal surface of the silicon carbide single crystal in a radial direction is 0.1° C./mm or less, and a radius of curvature of the growth crystal surface is 4.5 m or more, thereby producing a silicon carbide single crystal ingot having a growth length of 3 mm or more and an internal stress of 10 MPa or less. The ingot is then cut into a silicon carbide single crystal wafer.
Large grain quasi-single-crystal film and manufacturing method thereof
A large grain quasi-single-crystal film and a manufacturing method thereof are provided. The metal film having the <111> preferred orientation on its surface is subjected to mechanical tensile force to make the arrangement of crystal grains more ordered. The metal film is grown into a film with large crystal grains having an average diameter of over 500 microns by annealing at a temperature below the recrystallization temperature, thereby obtaining a large grain quasi-single-crystal film having the preferred directions of three axes. The large grain quasi-single-crystal film has a <110> preferred orientation along the tensile direction and a <211> preferred orientation along the direction vertical to the tensile force, and maintains a <111> preferred orientation on its top surface. The present invention can be used to produce highly anisotropic large-area quasi-single-crystal films, and can also be applied to grow 2-dimensional materials or develop anisotropic structures.
Group 13 Element Nitride Wafer With Reduced Variation In Off-Cut Angle
The invention relates to a two-dimensional crystal wafer of group 13 or III element nitride which is delimited by a face of orientation N, an opposing face of orientation E depending on the group 13 or III element, E being selected preferably from Ga, In, Al or a combination of these elements, charaterized in that the variation in crstalline off-cut angle in the largest dimension of said wafer is less than 5×10−3°/mm, and its curvature of geometric deformation of its faces exhibits a flexure in terms of absolute value of less than 10−.sup.3mm/mm of the largest dimension of said wafer.