In order to solve the leakage current saturation of Topmetal-II- and to maintain its low noise, Topmetal-IIa has been designed. The new chip has the same Rolling-Shutter module as Topmetal-II-. It contains a charge-collection electrode and a metal layer surrounding it, called guard ring. This new design contains three different sections. Section A has the same structure as Topmetal-II-, in that the electrode is exposed and guard ring is covered by insulating layer. Section B has both electrode and guard ring exposed. Section C has guard ring exposed but electrode covered by insulating layer. P...
