1. A method for producing a semiconductor light emitting device comprising the steps of:
(a) forming an insulating layer on a single-crystal silicon substrate;
(b) forming a gallium nitride type compound semiconductor layer as a buffer layer on the insulating layer;
(c) stacking on the buffer layer in sequence a lower cladding layer, an active layer, an upper cladding layer, and a cap layer, these layers being made of the gallium nitride type compound semiconductor;
(d) exposing a predetermined surface of the buffer layer by etching perpendicularly to the single-crystal silicon substrate;
(e) forming electrodes on both the cap layer and the predetermined surface of the buffer layer exposed by the etching treatment in step (d), whereby obtaining a semiconductor wafer having multilayer structure; and
(f) separating the semiconductor wafer to chips by dicing or by cleaving,
wherein the step of forming the insulating layer is implemented by removing an oxide film over the single-crystal silicon substrate and forming a silicon nitride layer by heating under an atmosphere of nitrogen gas.
2. The method for producing the semiconductor light emitting device of claim 1, wherein the single-crystal silicon substrate has a (111) crystal plane as a principal plane.
3. A method for producing a semiconductor light emitting device comprising the steps of:
(a) forming an insulating layer on a single-crystal silicon substrate;
(b) forming a gallium nitride type compound semiconductor layer as a buffer layer on the insulating layer;
(c) stacking on the buffer layer in sequence a lower cladding layer, an active layer, an upper cladding layer, and a cap layer, these layers being made of the gallium nitride type compound semiconductor;
(d) exposing a predetermined surface of the buffer layer by etching perpendicularly to the single-crystal silicon substrate;
(e) forming electrodes on both the cap layer and the predetermined surface of the buffer layer exposed by the etching treatment in step (d), whereby obtaining a semiconductor wafer having multilayer structure; and
(f) separating the semiconductor wafer to chips by dicing or by cleaving, wherein the step of forming the insulating layer is implemented by growing a layer of aluminum oxide.
4. A method for producing a semiconductor light emitting device comprising the steps of:
(j) preparing a group II-VI compound semiconductor substrate;
(k) stacking a buffer layer of gallium nitride type compound semiconductor on a principal plane of the group II-VI compound semiconductor substrate;
(l) stacking on the buffer layer in sequence a lower cladding layer, an active layer, an upper cladding layer, and a cap layer, these layers being made of gallium nitride semiconductor, with matching crystal lattice of each layer to one another;
(m) forming electrodes on both the top of the cap layer and the bottom of the group II-VI compound semiconductor substrate, whereby obtaining a semiconductor wafer having multilayer structure; and
(n) cleaving the semiconductor wafer to chips.
5. The method for producing a semiconductor light emitting device of claim 4, wherein the step of stacking the buffer layer is implemented by forming a low-temperature buffer layer at low temperature and then, by forming a high-temperature buffer layer at high temperature.
6. The method for producing a semiconductor light emitting device of claim 4, wherein the buffer layers are made of n-type GaN, the lower cladding layer is made of n-type AlxGa1\u2212xN (0<x<1), the active layer is made of GanIn1\u2212nN (0<n\u22661), the upper cladding layer is made of p-type AlxGa1\u2212xN (0<x<1), and the cap layer is made of p-type GaN.
7. The method for producing a semiconductor light emitting device of claim 4, wherein the group II-VI compound semiconductor substrate having a principal plane, the principal plane being a top surface comprising group VI atoms of the group II-VI compound semiconductor substrate, is prepared.
8. A method for producing a semiconductor light emitting device comprising the steps of:
(o) preparing a group III-V compound semiconductor substrate, said group III-V compound semiconductor selected from the group consisting of GaAs, InAs, GaP, and InP;
(p) stacking a buffer layer of gallium nitride type compound semiconductor on a principal plane of the group III-V compound semiconductor substrate;
(q) stacking on the buffer layers in sequence a lower cladding layer, an active layer, an upper cladding layer, and a cap layer, these layers being made of gallium nitride type semiconductor, with matching crystal lattice of each layer to one another;
(r) forming electrodes on both the top of the cap layer and the bottom of the group III-V compound semiconductor substrate, whereby obtaining a semiconductor wafer having multilayer structure; and
(s) cleaving the semiconductor wafer to chips.
9. The method for producing semiconductor light emitting device of claim 8, wherein the step of forming the buffer layers is implemented by forming a low-temperature buffer layer at low temperature and then, by forming a high-temperature buffer layer at high temperature.
10. The method for producing the semiconductor light emitting device of claim 8, wherein the group III-V compound semiconductor substrate having a principal plane, the principal plane being a top surface comprising group V atoms of the group III-V compound semiconductor substrate, is prepared.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of operating a magnetic resonance system in order to perform magnetic resonance measurements on a sample, comprising:
applying, by the magnetic resonance system, a first predetermined number of magnetic resonance pulse trains as a source of magnetic resonance excitation in order to generate a spectrum of excitation frequencies, each pulse train of the magnetic resonance pulse trains, having a constant amplitude and including a second predetermined number of pulses spaced by a predetermined time interval, each of the magnetic resonance pulse trains being modulated by a bent function; and
sampling, by the magnetic resonance system, magnetic resonance data after each of the pulses of each of the magnetic resonance pulse trains,
wherein each of the magnetic resonance pulse trains being modulated by the bent function causes:
(i) each of the magnetic resonance pulse trains to be constant in power, and
(ii) a Walsh transform of the sequence of phases of each of the magnetic resonance pulse trains, to also be constant in power.
2. A method according to claim 1, wherein the bent function is chosen such that the magnetic resonance pulse trains include a series of a first predetermined number of wavelet functions, and wherein each pulse train of the magnetic resonance pulse trains is defined by a second predetermined number of discrete points in time.
3. A method according to claim 1, wherein a spectrum of excitation frequencies covers frequencies of zero and integer multiples of a frequency interval.
4. A method according to claim 3, wherein the frequency interval is selected as the reciprocal value of the product of the first predetermined number and the predetermined time interval.
5. A method according to claim 1, wherein the predetermined time interval is determined whereby with the application of each pulse of the magnetic resonance pulse trains, the net magnetization of the sample is rotated by a small flip angle.
6. A Magnetic Resonance measurement apparatus employing the method of claim 1, comprising:
a) a magnetic arrangement configured to create a static magnetic field in a sample;
b) a coil configured to excite, refocus and sample a spin signal within the sample, and
c) a controller operative in order to cause the magnet arrangement and the coil to perform the applying step of claim 1 as part of the method of performing magnetic resonance measurements on the sample.
7. A Magnetic Resonance measurement apparatus according to claim 6, wherein the magnet arrangement additionally comprises;
at least one magnet, of at least one of the following kinds of magnets:
a) a superconducting magnet;
b) a permanent magnet; and
c) an electromagnet.
8. A Magnetic Resonance measurement apparatus according to claim 6, wherein the magnet arrangement is a single-sided magnet arrangement.
9. A Magnetic Resonance measurement apparatus according to claim 6, wherein the controller is further operative in order to cause the magnet arrangement and coil to generate magnetic gradient fields and to produce a spatially resolved sampling of magnetic resonance measurement signals.
10. A method of operating a magnetic resonance system according to claim 1, wherein the magnetic resonance measurements are nuclear magnetic resonance (NMR) measurements.
11. A method of operating a magnetic resonance system according to claim 10, wherein the NMR measurements include magnetic resonance imaging (MRI) measurements.
12. A method of operating a magnetic resonance system according to claim 1, wherein the magnetic resonance measurements are nuclear quadrupole resonance (NQR) measurements.
13. A method of operating a magnetic resonance system according to claim 12, wherein the presence of at least one of the following materials is detected by the respective NQR measurements:
a) explosives; and
b) narcotics.
14. A method of operating a magnetic resonance system according to claim 1, wherein the magnetic resonance measurements are electron spin resonance (ESR) measurements.
15. A method of operating a magnetic resonance system according to claim 1, wherein the magnetic resonance measurements include at least one of the following:
a) bore-hole NMR measurements;
b) well-logging measurements; and
and measurements below the earth surface in porous environments comprising fluids.