摘要:
Minority carrier diffusion lengths are determined fast, accurately, and conveniently by illuminating a surface of the semiconductor wafer (8) with a beam (7) composed of a plurality of light fluxes each having a different wavelength modulated at a different frequency (f1, f2). Surface photovoltages induces by different light fluxes are simultaneously detected by monitoring surface photovoltage signals at the different modulation frequences (f1, f2). The surface photovoltage signals are frequency calibrated and then used to calculated a minority carrier diffusion length.
摘要:
Die Erfindung betrifft ein Verfahren und eine Vorrichtung zur Durchführung des Verfahrens zur Qualitätskontrolle eines Photosensors 21, insbesondere eines Photodiodenarrays, dessen Ausgangssignal von der Intensität eines mit elektromagnetischen Wellen gebildeten Eingangssignals abhängt. Der zu testende Photosensor 21 wird mit die Eingangssignale ausbildenden Stimuliersignalen unter Variation der Stimuliersignalintensität der Stimuliersignale beaufschlagt. Dabei werden die zugehörigen Ausgangssignale des zu testenden Photosensors 21 wird gemessen und zu Auswertungszwecken erfaßt. Der Photosensor 21 wird vorzugsweise mit wenigstens zwei unabhängig voneinander steuerbaren, sich überlagernden individuellen Stimuliersignalen 41, 42, 43, 44 individueller Stimuliersignalintensität beaufschlagt. Die Einstellung der unterschiedlichen Stimuliersignalintensität der individuellen Stimuliersignale 41, 42, 43, 44 erfolgt mit Hilfe einer mit der Stimuliersignalquelle 31, 32, 33, 34 gekoppelten Kontrolleinheit 55 und die Messung und Erfassung der Ausgangssignale des Photosensors erfolgt mit Hilfe einer Meßdatenerfassungseinheit 65.
摘要:
A tester (10) for electrical traces (85) such as on a circuit board (80) includes an electromagnetic beam source (20) such as a laser producing an ultraviolet beam (24), a vacuum chamber (12), an electrode circuit (49) including electrodes (51) and corresponding electronics (55) including ammeters (59) for measuring photoelectron flow between traces (85) and electrodes (51), a controller (71), laser beam optics (41, 44, 46), an image acquisition system, and a pair of broadband UV lights. The board containing traces (85) under test is disposed in the vacuum chamber (12) at lowered pressure with grid electrodes (51) lying close to the trace area (85) on each side of the board. Electrode electronics (55) selectively maintain a known potential on each electrode (51). The exact location of traces (85) are determined by an image acquisition system. The board (80) and traces (85) are initialized to a known voltage. Photoelectric effect using ultraviolet laser beams (24) is used to determine continuity between two points (87) on a trace (85) and shorts between traces (85).
摘要:
The peripheral circuitry (350, 360, ESD, BH) of an integrated circuit die on a wafer is tested without physically contacting the bond pads of the die.
摘要:
Certain material and objects can be characterized by a frequency-dependent absorption, dispersion, and reflection of terahertz transients in signals which pass illuminate the material or object. The present terahertz imaging system analyses that frequency dependence in the time-domain by collecting that transmitted signal propagating through the object and then processing the information contained in those signals for every point or "pixel" on that object. This is a non-invasive imaging technique that is capable of differentiating between different materials, chemical compositions, or environments.
摘要:
L'invention concerne la réalisation d'un échantillon de référence pour un étalonnage d'un appareil de caractérisation de doses implantées sur une plaquette (1), consistant à définir une succession d'au moins deux bandes parallèles (Bi) sur la plaquette (1), à déposer un premier masque d'implantation sur la plaquette selon un motif laissant accessible une première bande (B1), à effectuer une première implantation ionique d'une première dose, à éliminer le premier masque et à déposer un deuxième masque d'implantation sur la plaquette (1) selon un motif laissant accessible la première bande (B1) ainsi qu'une deuxième bande (B2) contiguë, à effectuer une deuxième implantation ionique d'une deuxième dose, et à éliminer le deuxième masque.
摘要:
A method is provided for determining the minority carrier surface recombination lifetime constant (t s ) of a specimen of semiconductor material. The specimen is positioned between a pair of electrodes, the specimen being disposed on one of the electrodes and being spaced form the other electrode. A signal is provided corresponding to the capacitance between the specimen and the electrode spaced from the specimen. A region of the surface of the specimen is illuminated with a beam of light of predetermined wavelengths and which is intensity modulated at a predetermined frequency and varying in intensity over a predetermined range. A fixed bias voltage V g is applied between the pair of electrodes, the fixed bias voltage being of a value such that the semiconductor surface is in a state of depletion or inversion. A signal is provided representing the ac photocurrent induced at the region of the specimen illuminated by the light beam. The intensity of the light beam and frequency of modulation of the light beam are selected such that the ac photocurrent is nearly proportional to the intensity of the light beam and reciprocally proportional to the frequency of modulation of the light beam. A signal is provided corresponding to the illumination intensity of the beam of light. The surface minority carrier recombination time constant (t s ) is then determined using the ac photocurrent capacitance and illumination intensity information.
摘要:
Fault diagnosis of an HBT-based circuit using electroluminescence scans the circuit with a microscope coupled to a photodetector. The photodetector detects the light emitted by active elements of the circuit when powered and collected by the microscope. The light is converted into an electrical signal that may be displayed on an appropriate monitor for observation. The circuit may be powered with a steady source, a pulsing source or a gradually increasing source to detect which active elements are "on" or "off", which elements "latch up", and which elements "oscillate" contrary to expectations.