摘要:
SiC is a very stable substance, and it is difficult to control the condition of a SiC surface to be suitable for crystal growth in conventional Group III nitride crystal growing apparatuses. This problem is solved as follows. The surface of a SiC substrate 1 is rendered into a step-terrace structure by performing a heating process in an atmosphere of HCl gas. The surface of the SiC substrate 1 is then treated sequentially with aqua regia, hydrochloric acid, and hydrofluoric acid. A small amount of silicon oxide film formed on the surface of the SiC substrate 1 is etched so as to form a clean SiC surface 3 on the substrate surface. The SiC substrate 1 is then installed in a high-vacuum apparatus and the pressure inside is maintained at ultrahigh vacuum (such as 10−6 to 10−8 Pa). In the ultrahigh vacuum state, a process of irradiating the surface with a Ga atomic beam 5 at time t1 at temperature of 800° C. or lower and performing a heating treatment at 800° C. or higher is repeated at least once. The temperature is then set to the growth temperature of an AlN film, and the SiC substrate surface 3 is initially irradiated with Al atoms 8a in ultrahigh vacuum state, followed by the feeding of N atoms 8b.
摘要:
SiC is a very stable substance, and it is difficult to control the condition of a SiC surface to be suitable for crystal growth in conventional Group III nitride crystal growing apparatuses. This problem is solved as follows. The surface of a SiC substrate 1 is rendered into a step-terrace structure by performing a heating process in an atmosphere of HCl gas. The surface of the SiC substrate 1 is then treated sequentially with aqua regia, hydrochloric acid, and hydrofluoric acid. A small amount of silicon oxide film formed on the surface of the SiC substrate 1 is etched so as to form a clean SiC surface 3 on the substrate surface. The SiC substrate 1 is then installed in a high-vacuum apparatus and the pressure inside is maintained at ultrahigh vacuum (such as 10−6 to 10−8 Pa). In the ultrahigh vacuum state, a process of irradiating the surface with a Ga atomic beam 5 at time t1 at temperature of 800° C. or lower and performing a heating treatment at 800° C. or higher is repeated at least once. The temperature is then set to the growth temperature of an AlN film, and the SiC substrate surface 3 is initially irradiated with —Al atoms 8a in ultrahigh vacuum state, followed by the feeding of N atoms 8b.
摘要:
4H—InGaAlN alloy based optoelectronic and electronic devices on non-polar face are formed on 4H—AlN or 4H—AlGaN on (11-20) a-face 4H—SiC substrates. Typically, non polar 4H—AlN is grown on 4H—SiC (11-20) by molecular beam epitaxy (MBE). Subsequently, III-V nitride device layers are grown by metal organic chemical vapor deposition (MOCVD) with 4H-polytype for all of the layers. The non-polar device does not contain any built-in electric field due to the spontaneous and piezoelectric polarization. The optoelectronic devices on the non-polar face exhibits higher emission efficiency with shorter emission wavelength because the electrons and holes are not spatially separated in the quantum well. Vertical device configuration for lasers and light emitting diodes (LEDs) using conductive 4H—AlGaN interlayer on conductive 4H—SiC substrates makes the chip size and series resistance smaller. The elimination of such electric field also improves the performance of high speed and high power transistors. The details of the epitaxial growth s and the processing procedures for the non-polar III-V nitride devices on the non-polar SiC substrates are also disclosed.
摘要:
4H-InGaAlN alloy based optoelectronic and electronic devices on non-polar face are formed on 4H-AlN or 4H-AlGaN on (11-20) a-face 4H-SiC substrates. Typically, non polar 4H-AlN is grown on 4H-SiC (11-20) by molecular beam epitaxy (MBE). Subsequently, III-V nitride device layers are grown by metal organic chemical vapor deposition (MOCVD) with 4H-polytype for all of the layers. The non-polar device does not contain any built-in electric field due to the spontaneous and piezoelectric polarization. The optoelectonic devices on the non-polar face exhibits higher emission efficiency with shorter emission wavelength because the electrons and holes are not spatially separated in the quantum well. Vertical device configuration for lasers and light emitting diodes(LEDs) using conductive 4H-AlGaN interlayer on conductive 4H-SiC substrates makes the chip size and series resistance smaller. The elimination of such electric field also improves the performance of high speed and high power transistors. The details of the epitaxial growth s and the processing procedures for the non-polar III-V nitride devices on the non-polar SiC substrates are also disclosed.
摘要:
Disclosed are a diboride single crystal substrate which has a cleavage plane as same as that of a nitride compound semiconductor and is electrically conductive; a semiconductor laser diode and a semiconductor device using such a substrate and methods of their manufacture wherein the substrate is a single crystal substrate 1 of diboride XB2 (where X is either Zr or Ti) which is facially oriented in a (0001) plane 2 and has a thickness of 0.1 mm or less. The substrate 1 is permitted cleaving and splitting along a (10-10) plane 4 with ease. Using this substrate to form a semiconductor laser diode of a nitride compound, a vertical structure device can be realized. Resonant planes of a semiconductor laser diode with a minimum of loss can be fabricated by splitting the device in a direction parallel to the (10-10) plane. A method of manufacture that eliminates a margin of cutting is also realized.
摘要:
Disclosed are a diboride single crystal substrate which has a cleavage plane as same as that of a nitride compound semiconductor and is electrically conductive; a semiconductor laser diode and a semiconductor device using such a substrate and methods of their manufacture wherein the substrate is a single crystal substrate 1 of diboride XB2 (where X is either Zr or Ti) which is facially oriented in a (0001) plane 2 and has a thickness of 0.1 mm or less. The substrate 1 is permitted cleaving and splitting along a (10-10) plane 4 with ease. Using this substrate to form a semiconductor laser diode of a nitride compound, a vertical structure device can be realized. Resonant planes of a semiconductor laser diode with a minimum of loss can be fabricated by splitting the device in a direction parallel to the (10-10) plane. A method of manufacture that eliminates a margin of cutting is also realized.
摘要:
A field effect transistor comprises a SiC substrate 1, a source 3a and a drain 3b formed on the surface of the SiC substrate 1, an insulating structure comprising an AlN layer 5 formed in contact with the SiC surface and having a thickness of one molecule-layer or greater, and a SiO2 layer formed thereon, and a gate electrode 15 formed on the insulation structure. Leakage current can be controlled while the state of interface with SiC is maintained in a good condition.
摘要:
A field effect transistor comprises a SiC substrate 1, a source 3a and a drain 3b formed on the surface of the SiC substrate 1, an insulating structure comprising an AlN layer 5 formed in contact with the SiC surface and having a thickness of one molecule-layer or greater, and a SiO2 layer formed thereon, and a gate electrode 15 formed on the insulation structure. Leakage current can be controlled while the state of interface with SiC is maintained in a good condition.
摘要:
A design support method for causing a computer using layout data for providing a layout in which macro cells are arranged and in which power supply wirings are formed at certain intervals in each wiring layer to execute, the method including: extracting a set of adjacent macro cells from the layout data; specifying a region located between macro cells that constitute the set of adjacent macro cells extracted in the extracting step from among row regions included in the layout represented by the layout data; detecting a power supply wiring of a specific wiring layer in a projection area located above the region specified in the specifying step, the specific wiring layer being higher than a bottom layer of the layout represented by the layout data; and outputting a region where no power supply wiring of the specific wiring layer is detected in the detecting step.
摘要:
A design support method for causing a computer using layout data for providing a layout in which macro cells are arranged and in which power supply wirings are formed at certain intervals in each wiring layer to execute, the method including: extracting a set of adjacent macro cells from the layout data; specifying a region located between macro cells that constitute the set of adjacent macro cells extracted in the extracting step from among row regions included in the layout represented by the layout data; detecting a power supply wiring of a specific wiring layer in a projection area located above the region specified in the specifying step, the specific wiring layer being higher than a bottom layer of the layout represented by the layout data; and outputting a region where no power supply wiring of the specific wiring layer is detected in the detecting step.