Title :
Simulations of electric potential and field profiles in Si microstrip detectors using the guard-strip concept
Author_Institution :
Brookhaven Nat. Lab., Upton, NY, USA
fDate :
8/1/2001 12:00:00 AM
Abstract :
Two-dimensional (2-D) simulations of the electrical properties of Si microstrip detectors with various strip width/pitch configurations have been systematically performed using a processing and device simulation tool. It has been found that the detector full depletion voltage (Vfd) depends greatly on the ratios of strip width (W) to pitch (P) and pitch to detector thickness (d). Vfd increases with the decreasing ratio of W/P:Vfd for W/P=0.1(P=100 μm) and is almost twice that of a bulk detector (W/P=1) for different bulk resistivities (simulation of before and after radiation). The increasing rate of Vfd with decreasing W/P is much higher when W/P<0.3. It has also been found that, for a given strip width, the strip pitch should be kept smaller than the sum of detector thickness and strip width, i.e., P<d+W or P<d (if W≪d). Otherwise, the value of Vfd will be affected significantly (much larger than that of a bulk detector), It is clearly shown through the simulation that this increase of Vfd is due to the lateral depletion from the strip edge. A new width/pitch configuration with guard strips is proposed, which has shown great promise to push the W/P ratio down to 0.1 without greatly affecting the detector full depletion voltage
Keywords :
electric potential; radiation effects; semiconductor device breakdown; silicon radiation detectors; Si; Si microstrip detectors; bulk resistivities; detector full depletion voltage; electric potential; electrical properties; field profiles; guard-strip concept; lateral depletion; pitch to detector thickness; strip width/pitch configurations; width/pitch configuration; Conductivity; Diodes; Electric potential; Large Hadron Collider; Microstrip; Radiation detectors; Silicon radiation detectors; Strips; System testing; Voltage;
Journal_Title :
Nuclear Science, IEEE Transactions on