Boron filling of high aspect ratio holes by chemical vapor deposition for solid-state neutron detector applications

A multiple deposition and etching process has been developed to enable high fill factor boron deposition in high aspect ratio holes fabricated in a (100) silicon substrate. The boron deposition was carried out using low-pressure chemical vapor deposition and the etching was done by inductively coupled plasma reactive ion etching technique. The boron deposition processes were carried out under different conditions in order to find a baseline process condition. The boron etching processes done under different conditions with the photoresist as the mask are also discussed. Finally, the fabricated neutron detector with the highest fill factor was characterized for the thermal neutron detection efficiency. VC 2012 American Vacuum Society. [http://dx.doi.org/10.1116/1.4742856]