摘要:
A method of producing a compound semiconductor device using a lift-off process. The lift-off process includes forming a resist mask having an electrode opening on an active layer of a compound semiconductor that is on a substrate of a compound semiconductor; forming a metal layer on the resist mask and the active layer in the electrode opening; and dissolving the resist mask and removing the metal layer on the resist mask, leaving the metal layer on the active layer in the electrode opening as an electrode. The resist mask is removed sufficiently by using a resist remover consisting essentially of at least one compound selected from an amine-including compound and nitrogen-including cyclic compounds so that the residual resist mask need not be removed by ashing.
摘要:
A GaAs-based semiconductor field-effect transistor in which electrons flowing from a source electrode to a drain electrode are controlled by a signal supplied to a gate electrode. The transistor includes an active layer made of a GaAs-based semiconductor material. A source electrode and a drain electrode are formed on the active layer. A gate electrode is formed on the active layer between the source electrode and the drain electrode. The thickness of an oxide layer of the GaAs-based semiconductor material on the active layer is approximately equal to the lattice constant of the GaAs-based semiconductor material. The thickness of the oxide layer is preferably about 4 through 6 Å, and, more preferably, about 5 Å.
摘要:
A method of manufacturing a junction field-effect transistor which controls variations of p-type impurities in a gate region and obtains a favorable PN junction characteristic includes: depositing ZnO in a thin layer by a sputtering method on a surface of a region in which a gate electrode of an n+-AlGaAs layer formed on a GaAs substrate is to be formed; forming a p-type gate region by solid-phase diffusion which is performed by processes of rapid heating and fast cooling; removing the ZnO with wet etching using tartaric acid and the like so as to expose the p-type gate region; and forming the gate electrode on the exposed p-type gate region.
摘要:
A method of fabricating a thin film piezoelectric device includes preparing a semiconductor substrate having a surface; forming an etch stopping layer having an etching rate on the surface of the semiconductor substrate; forming a first semiconductor layer having an etching rate higher than the etching rate of the etch stopping layer on the etch stopping layer; forming a first electrode on a region of the first semiconductor layer; forming a piezoelectric film on the first electrode; forming a second electrode on the piezoelectric film; and etching a portion of the first semiconductor layer where the first electrode, the piezoelectric film, and the second electrode overlap, from the surface of the first semiconductor layer, selectively with respect to the etch stopping layer, thereby forming a cavity in the first semiconductor layer. Even when a compound semiconductor is employed as the substrate, the etching forming a cavity is stopped at the etch stopping layer in the direction perpendicular to the surface of the first semiconductor layer so that a cavity having a uniform depth is produced with high controllability.
摘要:
A compound semiconductor device includes a carrier supply layer supplying free charge carriers and having high dopant impurity concentration regions with a prescribed width, disposed in stripe shapes along a main current flow direction, parallel to each other, and spaced at an interval, and a carrier channel layer to which free charge carriers are supplied from the carrier supply layer including an electron channel having a high free carrier density at portions corresponding to respective high dopant impurity concentration regions of the carrier supply layer in the vicinity of a heterojunction interface. The heterojunction interface formed by the carrier channel layer and the carrier supply layer has a periodic undulating shape with convex portions and valley portions in stripe shapes extending parallel to the main current flow direction. A pseudo one-dimensional electron channel is formed in the vicinity of the high dopant impurity concentration region of the carrier supply layer whereby electron mobility is increased. The regions other than the high dopant impurity concentration regions of the carrier supply layer have a low dopant impurity concentration whereby the charge carrier quantity and output per unit chip area are increased, thereby increasing power output without increasing chip area.