Abstract: A semiconductor device comprises a silicon substrate 10 of a resistivity above or equal to 800 &OHgr;·cm and an oxygen concentration under or equal to 5×1017 cm−3, and an inductor 32b formed in the silicon substrate. A concentration of oxygen contained in the silicon substrate is set to be low, whereby the silicon substrate is less vulnerable to thermal donor effect, and even in a case that a silicon substrate of high resistivity is used, a semiconductor device which suppresses conversion of a conduction type of the silicon substrate while having an inductance of high Q. It is not necessary to bury a highly resistive layer in the silicon substrate, whereby a semiconductor device having an inductance of high Q can be fabricated by simple fabrication steps, which contributes to cost reduction of the semiconductor device.

Abstract: A semiconductor device comprises a silicon substrate 10 of a resistivity above or equal to 800 &OHgr;·cm and an oxygen concentration under or equal to 5×1017 cm−3, and an inductor 32b formed in the silicon substrate. A concentration of oxygen contained in the silicon substrate is set to be low, whereby the silicon substrate is less vulnerable to thermal donor effect, and even in a case that a silicon substrate of high resistivity is used, a semiconductor device which suppresses conversion of a conduction type of the silicon substrate while having an inductance of high Q. It is not necessary to bury a highly resistive layer in the silicon substrate, whereby a semiconductor device having an inductance of high Q can be fabricated by simple fabrication steps, which contributes to cost reduction of the semiconductor device.