A device for converting electrical energy, including at least one switching-type semiconductor component, a cooling path for cooling the semiconductor component, and a device for determining a degradation of the cooling path based on a current having a predetermined current intensity that flows through the component. The device provides that the semiconductor component includes an optically active semiconductor material, which generates light having a brightness that is dependent on a temperature of the semiconductor component when the semiconductor component is traversed by current having a predetermined current intensity, and the device for determining the degradation includes a brightness sensor for recording the brightness of the generated light. The device has the advantage that the device for determining the degradation and the component are inherently galvanically isolated, and the degradation can be determined at a high resolution.

According to the present invention, there is provided a group III nitride semiconductor substrate (free-standing substrate 30) that is formed of group III nitride semiconductor crystals. Both exposed first and second main surfaces in a relationship of top and bottom are semipolar planes. A variation coefficient of an emission wavelength of each of the first and second main surfaces, which is calculated by dividing a standard deviation of an emission wavelength by an average value of the emission wavelength, is 0.05% or less in photoluminescence (PL) measurement in which mapping is performed in units of an area of 1 mm.sup.2 by emitting helium-cadmium (HeCd) laser, which has a wavelength of 325 nm and an output of 10 mW or more and 40 mW or less, at room temperature. In a case where devices are manufactured over the free-standing substrate 30, variations in quality among the devices are suppressed.

An inspection system includes a light source, a mirror, Galvano mirrors, a casing that holds the mirror and the Galvano mirrors inside and includes an attachment portion for attaching an optical element, and a control unit that controls a deflection angle of the Galvano mirrors, wherein the control unit controls the deflection angle so that an optical path optically connected to a semiconductor device is switched between a first optical path passing through the Galvano mirrors and the mirror, and a second optical path passing through the Galvano mirrors and the attachment portion, and controls the deflection angle so that the deflection angle when switching to the first optical path has been performed and the deflection angle when switching to the second optical path has been performed do not overlap.

Various approaches to can be used to interrogate a surface such as a surface of a layered semiconductor structure on a semiconductor wafer. Certain approaches employ Second Harmonic Generation and in some cases may utilize pump and probe radiation. Other approaches involve determining current flow from a sample illuminated with radiation.

Embodiments relate to functional test methods useful for fabricating products containing Light Emitting Diode (LED) structures. In particular, LED arrays are functionally tested by injecting current via a displacement current coupling device using a field plate comprising of an electrode and insulator placed in close proximity to the LED array. A controlled voltage waveform is then applied to the field plate electrode to excite the LED devices in parallel for high-throughput. A camera records the individual light emission resulting from the electrical excitation to yield a function test of a plurality of LED devices. Changing the voltage conditions can excite the LEDs at differing current density levels to functionally measure external quantum efficiency and other important device functional parameters.

Second Harmonic Generation (SHG) can be used to interrogate a surface such as a surface of a layered semiconductor structure on a semiconductor wafer. In some instances, SHG is used to evaluate an interfacial region such as between metal and oxide. Various parameters such as input polarization, output polarization, and azimuthal angle of incident beam, may affect the SHG signal. Accordingly, such parameters are varied for different types of patterns on the wafer. SHG metrology on various test structures may also assist in characterizing a sample.

A heat source position inside a measurement object is identified with high accuracy by improving time resolution. An analysis system according to the present invention is an analysis system that identifies a heat source position inside a measurement object, and includes a condition setting unit that sets a measurement point for one surface of the measurement object, a tester that applies a stimulation signal to the measurement object, a light source that irradiates the measurement point of the measurement object with light, a photo detector that detects light reflected from a predetermined measurement point on the surface of the measurement object according to the irradiation of light and outputs a detection signal, and an analysis unit that derives a distance from the measurement point to the heat source position based on the detection signal and the stimulation signal and identifies the heat source position.

Various approaches can be used to interrogate a surface such as a surface of a layered semiconductor structure on a semiconductor wafer. Certain approaches employ Second Harmonic Generation and in some cases may utilize pump and probe radiation. Other approaches involve determining current flow from a sample illuminated with radiation. Decay constants can be measured to provide information regarding the sample. Additionally, electric and/or magnetic field biases can be applied to the sample to provide additional information.

A method includes: providing a first semiconductor device including a backside interconnection structure, the first semiconductor device being formed by a semiconductor process; and generating a physical failure analysis model by an inspection process. The inspection process includes: directing an electron beam toward the frontside of the first semiconductor device; and applying an electrical signal to an electrical contact of the first semiconductor device through an electrical path that goes through a shunt board attached to a switchable interface trace bank, the electrical contact being associated with a position of the electron beam. The method further includes: generating a parameter of a revised semiconductor process according to the physical failure analysis model and the semiconductor process; and forming a second semiconductor device by the revised semiconductor process using the parameter.

A soft error inspection method for a semiconductor device includes: irradiating and scanning the semiconductor device with a laser beam or an electron beam; and measuring and storing a time of bit inversion for each of areas irradiated with the laser beam or the electron beam of the semiconductor device.