Semiconductor device and manufacturing method of the same

摘要

A variable capacitor includes an N<+> layer including a variable capacitance region, a P<+> layer epitaxially grown on the N<+> layer and formed from a SiGe film and a Si film, and a P-type electrode. An NPN-HBT (Hetero-junction Bipolar Transistor) includes a collector diffusion layer formed simultaneously with the N<+> layer of the variable capacitor, a collector layer, and a Si/SiGe layer epitaxially grown simultaneously with the P<+> layer of the variable capacitor. Since a depletion layer formed in a PN junction of the variable capacitor can extend entirely across the N<+> layer, reduction in variation range of the capacitance can be suppressed.