Abstract: A radio frequency module packaging system and method characterized by compact package size, reduced packaging loss and variation, and reduced heat generation. The radio frequency module is provided with via holes, electrodes for signals, and grounding electrodes on the surface of a substrate. Under the electrodes for signals, via holes are made, and on both sides of the electrodes for signals, grounding via holes are made so that these via holes form microstrip lines. Both input and output ends of a high frequency circuit including an active device, formed as the module's functional circuit on the substrate, are routed through the via holes and connected to another circuit.

Abstract: In a semiconductor device using tunnel current and a barrier layer, arrangements are provided to lower the resistance of the semiconductor device. In particular, arrangements are provided to lower the parasitic resistance of a device such as a field effect transistor or an HBT, as well as to provide high-performance low noise amplifiers, mixers and the like using such reduced resistance semiconductor devices. To achieve this reduced resistance, carrier concentration or effective mass is designed not to be uniform in at least one of the semiconductor layers holding a barrier layer therebetween. For example, in an area near the barrier layer, the carrier concentration distribution can be large or the effective mass distribution can be small.

Abstract: A semiconductor crystalline laminate structure wherein between a first semiconductor layer consisting of a first alloyed semiconductor and a second semiconductor layer which has an energy gap wider than that of the first alloyed semiconductor and a lattice constant smaller than that of the first alloyed semiconductor and consists of one semiconductor selected from a group of single-element semiconductor, compound semiconductor, and alloyed semiconductor which contain no semiconductor having a largest lattice constant among the semiconductor constituting the first alloyed semiconductor, a third semiconductor layer which consists of a second alloyed semiconductor having an energy gap wider than that of the first alloyed semiconductor and contains the semiconductor having a largest lattice constant among the semiconductors constituting the first alloyed semiconductor is formed in contact with these layers, a forming method for the semiconductor crystalline laminate structure, and a semiconductor device using the

Abstract: A method may be used to dry etch a sample including a plurality of regions different from each other in the photo-absorption of a light having a specified wavelength using an etching gas plasma. The method is capable of selectively etching the desired material from a plurality of materials having different types of band gap energies or from a plurality of materials having different band gap energies. The method includes a step of irradiating a light having the specified wavelength on the sample for reducing an etching rate of a region having a large photo-absorption coefficient to the light, thereby selectively etching a region having a small photo-absorption coefficient to the light.