Semiconductor device and production method therefor

Abstract

The present invention is related to a semiconductor device that forms an inductor on the same semiconductor substrate together with other active elements and a manufacturing method thereof. The semiconductor device of the present invention comprises a substrate, a semiconductor layer (high-resistance semiconductor layer) formed on this substrate that has an impurity concentration lower than the impurity concentration of the substrate or a first semiconductor layer (high-resistance semiconductor layer) of a first conducting type with an impurity concentration lower than the substrate and a second semiconductor layer of a second conducting type on the first layer, an insulating film formed on this high-resistance semiconductor layer (semiconductor layer, first semiconductor layer), and an inductor formed on this insulating film. The manufacturing method of the present invention successively forms a semiconductor layer on the substrate that has an impurity concentration lower than the substrate or a first semiconductor layer of a first conducting type with a low impurity concentration and a second semiconductor layer of a second conducting type on the first layer. The manufacturing method further forms an insulating film on the semiconductor layer or second semiconductor layer, forms a conducting film on the insulating film and then patterns the conducting film in a spiral shape to form an inductor. In this manner a composition is formed wherein the high-resistance semiconductor layer is between the insulating film under the inductor and the substrate or a pn junction and the high-resistance semiconductor layer. Even at high frequencies current flowing in the high-resistance semiconductor layer and substrate is reduced thereby controlling loss caused by this current which in turn decreases the parasitic capacitance making it possible to achieve a high-performance inductor with good device characteristics that has a high Q value and high inductance.

Dependencies are inferred from the claim text.