A Novel Silicon Detector for Energetic Electrons with Improved Linearity Characteristics

The paper describes a novel silicon detector with improved linearity characteristics for energetic electrons up to 50 keV. The modified pn-junction detector structure contains a buried implanted n(+)-layer (N~1-5E15 cm-3) in the n-type Si substrate which is attributed by a near-surface high-field region in the depletion zone. To enable a high-field region of several micrometers depth high-energy ion implantation with 31P ions of 10-30 MeV has been used. The corresponding electric field distribution of the novel detector is characterized by a constant electric field strength of 10-50 kV/cm from the surface down to the depth of the buried implanted layer. Detectors with considerable improved linearity up to electron current densities of 20 A/cm2 have been fabricated, which have been tested at the e-beam writer SB 350 of Leica Microsystems Lithography for electrons of 50 keV.