| 摘要 |
<p>The invention relates to an essentially discrete semiconductor device comprising a semiconductor body (10) having a first, preferably bipolar, transistor (T1) with a first region (1) forming a collector (1) of T1, and a second, preferably also bipolar, transistor (T2) with a second region (2) forming a collector (2) of T2, which transistors (T1, T2) are in a cascode configuration wherein the collector (1) of T1 is connected to the emitter (4) of T2. Such a device cannot suitably be used in a base station for mobile communication. According to the invention, the first region (1) and the second region (2) are positioned next to each other within a semiconductor region (5), a part of which situated below the first region (1) is provided with a higher doping concentration at the location of T1. In this way, T1 has a low collector-emitter breakdown voltage and a high cutoff frequency, whereas for T2 said voltage and frequency are, respectively, high(er) and low(er). The resultant device is very suitable, on the one hand, for a high voltage application, for example 28 V, and a high power application, for example 100 W and, on the other hand, the device can still operate at a very high speed and hence is very suitable for the above application. Moreover, the device can be manufactured very easily using a method according to the invention. Preferably, the device is rendered suitable for surface mounting, and the semiconductor body is attached to an isolating substrate (20), while the parts thereof that are situated outside T1 and T2 are removed.</p> |
