Monolithic integration of Si-PIN diodes and n-channel double-gate JFETʹs for room temperature X-ray spectroscopy

We report on Junction Field Effect Transistors and PIN diodes monolithically integrated on high-resistivity silicon by adopting a non-standard technology recently developed at IRST. In particular, a test structure, consisting of a small PIN diode DC-coupled to an integrated n-channel JFET in the double-gate configuration was fully characterised and spectroscopic measurements were carried out by adopting a novel double-feedback charge amplifier circuit. An ENC of about 60 electrons r.m.s. has been obtained at room temperature and at 10 μs shaping time; such a resolution is shown to be determined by the relatively high total capacitance present in this preliminary set-up, associated with the 1/f series noise of the transistor.