An improvement is achieved in the performance of a semiconductor device. A semiconductor device includes an n.sup.-type semiconductor region formed in a p-type well, an n-type semiconductor region formed closer to a main surface of a semiconductor substrate than the n.sup.-type semiconductor region, and a p.sup.-type semiconductor region formed between the n.sup.-type semiconductor region and the n-type semiconductor region. A net impurity concentration in the n.sup.-type semiconductor region is lower than a net impurity concentration in the n-type semiconductor region. A net impurity concentration in the p.sup.-type semiconductor region is lower than a net impurity concentration in the p-type well.

The present invention relates to a semiconductor laser for use in an optical module for measuring distances and/or movements, using the self-mixing effect. The semiconductor laser comprises a layer structure including an active region (3) embedded between two layer sequences (1, 2) and further comprises a photodetector arranged to measure an intensity of an optical field resonating in said laser. The photodetector is a phototransistor composed of an emitter layer (e), a collector layer (c) and a base layer (b), each of which being a bulk layer and forming part of one of said layer sequences (1, 2). With the proposed semiconductor laser an optical module based on this laser can be manufactured more easily, at lower costs and in a smaller size than known modules.

Certain embodiments of the present invention may be directed to a transistor structure. The transistor structure may include a semiconductor substrate. The semiconductor substrate may include a drift region, a collector region, an emitter region, and a lightly-doped/undoped region. The lightly-doped/undoped region may be lightly-doped and/or undoped. The transistor structure may also include a heterostructure. The heterostructure forms a heterojunction with the lightly-doped/undoped region. The transistor structure may also include a collector terminal. The collector terminal is in contact with the collector region. The transistor structure may also include a gate terminal. The gate terminal is in contact with the heterostructure. The transistor structure may also include an emitter terminal. The emitter terminal is in contact with the lightly-doped/undoped region and the emitter region.

A split electrode vertical cavity optical device includes an n-type ohmic contact layer, first through fifth ion implant regions, cathode and anode electrodes, first and second injector terminals, and p and n type modulation doped quantum well structures. The cathode electrode and the first and second ion implant regions are formed on the n-type ohmic contact layer. The third ion implant region is formed on the first ion implant region and contacts the p-type modulation doped QW structure. The fourth ion implant region encompasses the n-type modulation doped QW structure. The first and second injector terminals are formed on the third and fourth ion implant regions, respectively. The fifth ion implant region is formed above the n-type modulation doped QW structure and the anode electrode is formed above the fifth ion implant region.

A semiconductor device includes an n-type ohmic contact layer, cathode and anode electrodes, p-type and n-type modulation doped quantum well (QW) structures, and first and second ion implant regions. The anode electrode is formed on the first ion implant region that contacts the p-type modulation doped QW structure and the cathode electrode is formed by patterning the first and second ion implant regions and the n-type ohmic contact layer. The semiconductor device is configured to operate as at least one of a diode laser and a diode detector. As the diode laser, the semiconductor device emits photons. As the diode detector, the semiconductor device receives an input optical light and generates a photocurrent.

A method and a sensing device are provided. The sensing device may include a readout circuit, a bulk, a holding element and a heterojunction bipolar transistor; wherein heterojunction bipolar transistor is configured to generate detection signals responsive to a temperature of at least a portion of the heterojunction bipolar transistor; wherein the holding element is configured to support the heterojunction bipolar transistor; wherein the heterojunction bipolar transistor is thermally isolated from the bulk; wherein the readout circuit is electrically coupled to the heterojunction bipolar transistor; and wherein the readout circuit is configured to receive the detection signals and to process the detection signals to provide information about electromagnetic radiation that affected the temperature of the at least portion of the heterojunction bipolar transistor.

Methods and systems include constructing and operating a semiconductor device with a mid-band dopant layer. In various implementations, carriers that are optically excited in a mid-band dopant region may provide injection currents that may reduce transition times and increase achievable operating frequency in a bipolar junction transistor (BJT). In various implementations, carriers that are optically excited in a mid-band dopant region within a thyristor may improve closure transition time, effective current spreading velocity, and maximum rate of current rise.

An improvement is achieved in the performance of a semiconductor device. A semiconductor device includes an n.sup.-type semiconductor region formed in a p-type well, an n-type semiconductor region formed closer to a main surface of a semiconductor substrate than the n.sup.-type semiconductor region, and a p.sup.-type semiconductor region formed between the n.sup.-type semiconductor region and the n-type semiconductor region. A net impurity concentration in the n.sup.-type semiconductor region is lower than a net impurity concentration in the n-type semiconductor region. A net impurity concentration in the p.sup.-type semiconductor region is lower than a net impurity concentration in the p-type well.

A Dual-wavelength hybrid (DWH) device includes an n-type ohmic contact layer, cathode and anode terminal electrodes, first and second injector terminal electrodes, p-type and n-type modulation doped QW structures, and first through sixth ion implant regions. The first injector terminal electrode is formed on the third ion implant region that contacts the p-type modulation doped QW structure and the second injector terminal electrode is formed on the fourth ion implant region that contacts the n-type modulation doped QW structure. The DWH device operates in at least one of a vertical cavity mode and a whispering gallery mode. In the vertical cavity mode, the DWH device converts an in-plane optical mode signal to a vertical optical mode signal, whereas in the whispering gallery mode the DWH device converts a vertical optical mode signal to an in-plane optical mode signal.

A semiconductor device employs an epitaxial layer arrangement including a first ohmic contact layer and first modulation doped quantum well structure disposed above the first ohmic contact layer. The first ohmic contact layer has a first doping type, and the first modulation doped quantum well structure has a modulation doped layer of a second doping type. At least one isolation ion implant region is provided that extends through the first ohmic contact layer. The at least one isolation ion implant region can include oxygen ions. The at least one isolation ion implant region can define a region that is substantially free of charge carriers in order to reduce a characteristic capacitance of the device. A variety of high performance transistor devices (e.g., HFET and BICFETs) and optoelectronic devices can employ this device structure. Other aspects of wavelength-tunable microresonantors and related semiconductor fabrication methodologies are also described and claimed.