Abstract: A semiconductor device includes a first transistor of a normally-off type, a second transistor of a normally-on type, and a third transistor of a normally-on type. The first transistor and the second transistor are connected to each other in cascode. The third transistor is connected in parallel with the second transistor. Each of the second transistor and the third transistor has an off-state breakdown voltage higher than an off-state breakdown voltage of the first transistor. The third transistor has a turn-on time shorter than a turn-on time of the second transistor.

Abstract: Provided are a multiple-unit semiconductor device that enables space savings and a method for controlling such a semiconductor device. A multiple-unit semiconductor device is brought into conduction by a Si-FET being brought into conduction first and a GaN device being brought into conduction after the Si-FET has been brought into conduction.