Radio-frequency flexible electronics: Transistors and passives

Flexible electronics have customarily addressed low-frequency applications because the traditional materials for flexible electronics, such as polymer and non-crystalline inorganic semiconductors, have poor electronic properties. Fast flexible electronics that operate at radio frequencies (RF), particularly at microwave frequencies, could lead to a number of novel RF applications that rigid chip based solid-state electronics cannot easily fulfill. Single-crystal semiconductor nanomembranes that can be released from a number of wafer sources are mechanically very flexible and exhibit outstanding electronic properties that are equivalent to those of their bulk counterparts. These thin, flexible single-crystal materials can furthermore be placed, via transfer printing techniques, onto nearly any substrate, including flexible polymers, thus creating the opportunity to realize RF flexible electronics. In this paper, we will present various RF transistors made of semiconductor nanomembranes on plastic substrates, along with RF passives fabricated on the same flexible substrates. We will also elaborate on the difference between such flexible electronics and those made from thinned rigid wafers.