Abstract: Semiconductor devices for high frequency operations are described. The semiconductor devices include a substrate with an epitaxial layer. The epitaxial layer has higher resistivity than the substrate and includes a surface facing away from the substrate. The epitaxial layer includes a shallow trench isolation (STI) structure extended to a first depth from the surface, which is surrounded by a well structure. Underneath the STI structure, the epitaxial layer includes a lightly doped portion exclusive of dopant atoms of the well structure. Moreover, the STI structure includes an inner portion surrounded by a deep trench isolation structure extended to a second depth from the surface, the second depth being greater than the first depth. An integrated circuit component is located above the inner portion of the STI structure.

Abstract: A thin film resistor is formed to have very accurately defined dimensions which, in turn, allow the resistive value of the resistor to be very accurately defined. The resistor is formed on spaced-apart conductive pads which, in turn, are electrically connected to conductive plugs that are spaced apart from the resistor.

Abstract: A current mirror method is provided that can be utilized to evaluate thermal issues is silicon-on-insulator (SOI) bipolar junction transistors (BJTs). The method significantly improves safe operating area (SOA) measurement sensitivity. Unlike conventional methods, the current mirror method can provide quantitative analysis of the BJTs thermal instability over a wide power range, even in the apparent SOA of the device. This method can also predict and evaluate SOA with respect to emitter ballast resistance and current crowding.

Abstract: A method for quantifying safe operating regions within a safe operating area (SOA) for a bipolar junction transistor (BJT) by driving the device under test (DUT) as part of a current mirror circuit and monitoring variances in the current mirror ratio for various biasing conditions.