  This paper reports the last technological development on the Low Gain
Avalanche Detector (LGAD) and introduces a new architecture of these detectors
called inverse-LGAD (iLGAD). Both approaches are based on the standard
Avalanche Photo Diodes (APD) concept, commonly used in optical and X-ray
detection applications, including an internal multiplication of the charge
generated by radiation. The multiplication is inherent to the basic n++-p+-p
structure, where the doping profile of the p+ layer is optimized to achieve
high field and high impact ionization at the junction. The LGAD structures are
optimized for applications such as tracking or timing detectors for high energy
physics experiments or medical applications where time resolution lower than 30
ps is required. Detailed TCAD device simulations together with the electrical
and charge collection measurements are presented through this work.
