Deep trench etching in macroporous silicon application to photonic crystal gas sensing

We present a method to create at the same time trenches and ordered macropore arrays during photo-electrochemical etching of n-type silicon. This novel method allows in situ separation of single devices with a submicrometer precision. The limits of this new process are simulated using electrostatic models and are verified experimentally. This new techniques enables new device structures in macroporous silicon in the areas of photonics, sensing and electronics, as an example an photonic crystal gas sensor is shown