Abstract: A lightweight hand-held skin abnormality detection system includes a source of excitation light that causes tissue under examination to produce fluorescence light. The fluorescence light produced along with the beam of reference light is provided to a beam splitter which divides the fluorescence light and the reference light into separate optical channels. Each optical channel produces an image of the tissue under examination. A passive optical combiner superimposes the image produced by each optical channel for viewing by a user.

Abstract: A lightweight hand-held skin abnormality detection system includes a source of excitation light that causes tissue under examination to produce fluorescence light. The fluorescence light produced along with the beam of reference light is provided to a beam splitter which divides the fluorescence light and the reference light into separate optical channels. Each optical channel produces an image of the tissue under examination. A passive optical combiner superimposes the image produced by each optical channel for viewing by a user.

Abstract: A lightweight hand-held skin abnormality detection system includes a source of excitation light that causes tissue under examination to produce fluorescence light. The fluorescence light produced along with the beam of reference light is provided to a beam splitter which divides the fluorescence light and the reference light into separate optical channels. Each optical channel produces an image of the tissue under examination. A passive optical combiner superimposes the image produced by each optical channel for viewing by a user.

Abstract: A method of manufacturing an integrated lateral transistor in which the depth and the doping level of the emitter region are such that the diffusion length of the minority carriers vertically injected into it is larger than or equal to the thickness of the emitter region. The distance between the peripheries of an electrical emitter connection zone and the emitter region is nominally larger than the alignment tolerance of an emitter contact window. This permits obtaining a transistor having an improved current amplification. An integrated circuit includes a lateral transistor, in which the ratio between the surface of the emitter region and that of the electrical emitter connection zone advantageous lies between 20 and 200.

Abstract: A semiconductor device including a vertical transistor, for example of the pnp type, having a p-type substrate (1) which forms the collector, with at its surface an epitaxial n-type layer (3) in which a p-type emitter region (15, 16) is formed, while the portion (9) of the epitaxial layer (3) lying between the emitter (15, 16) and the collector (1) forms the base. In this vertical transistor, the current gain is very strongly increased when the emitter is formed by a first partial emitter region which is weakly p-type doped and which extends below an insulating layer (6) and by a second partial emitter region (16) which is strongly p.sup.++ -type doped and which extends below the contact zone (26) of the emitter defined by an opening in the insulating layer (6). The respective thicknesses and doping levels of the first (15) and second (16) emitter regions are provided such that the first region is transparent to electrons and the second forms a screen against electrons.

Abstract: A bipolar lateral transistor, for example of the pnp type, is contained in a semiconductor device. The lateral transistor has a p-type emitter region and a p-type collector region laterally spaced apart by an n-type base region. This lateral transistor is formed in an n-type epitaxial layer at the surface of a p-type substrate. The transistor further has a n.sup.++ -type buried layer. The current gain in this lateral transistor is strongly increased by forming the emitter from a first partial emitter region which is weakly p-type doped and extends below an insulating layer, and a second partial emitter region which is strongly P.sup.++ -type doped and extends below the contact zone of the emitter, which is defined by an opening in the insulating layer. The respective thicknesses and doping levels of the first and second emitter regions are provided such that the first region is transparent to electrons and the second region forms a screen against electrons.

Abstract: The invention relates to an integrated circuit having a vertical transistor. According to the invention, a transistor having a current amplification .beta. considerably higher than a conventional transistor is obtained due to the fact that the emitter (5) of the transistor has a thickness and a doping level such that the diffusion length of the minority charge carriers injected vertically into the latter is greater than or equal to the thickness of the emitter (5) and the emitter contact region is so small that during operation the total current of minority charge carriers injected from the base into the emitter region is much smaller than the current density of minority carriers injected from the base into the emitter region under the emitter contact region multiplied by the total surface area of the emitter region.

Abstract: An integrated circuit includes a lateral transistor which has emitter regions (7) and collector regions (8) of a first conductivity type laterally spaced apart and included in a region (4, 5) of a second conductivity type opposed to the first. The lateral space (4) of the region (4, 5) of the second type situated between the emitter (7) and collector (8) regions forms the base of the transistor, with the emitter region (7) having a depth and a doping level which are such that the diffusion length of the minority carriers injected vertically therein is greater than or equal to the width of the region, which region has an elongate shape in at least a longitudinal direction, while the lateral transistor has its contour surrounded by a deep insulating layer (12).

Abstract: The invention relates to an integrated circuit including a vertical transistor having an emitter having at least one zone (12), a base (2) having a base contacting region (15) adjoining a major surface of the integrated circuit, and a collector (5). The base is less than or equal to the diffusion length of the minority charge carries in these regions. The ratio between the surface S.sub.x of a base contacting region (15) and the surface S.sub.M of a base contact window region is at least equal to 10, and when the base contacting region (15) has a surface smaller than 5 times that of the emitter region. The transistor exhibits improved inverse current amplification.

Abstract: The invention relates to an integrated circuit having a lateral transistor, whose emitter region has a depth and a doping level such that the diffusion length of the minority charge carriers vertically injected into this region is greater than or equal to the thickness of the said region, the ratio between the surface of the emitter region and that of the electrical connection emitter zone being at least equal to 20. The current amplification .beta. of such a transistor is considerably increased by giving the emitter region an elongate shape in a longitudinal direction, the ratio between the largest longitudinal dimension and the largest transversal dimension being at least equal to 5.