Method to prevent latch-up and improve breakdown voltage in SOI MOSFETS

摘要

SOI (silicon-on-insulator) technology has been touted as a promising approach for fabricating an advanced integrated circuits because of its advantage over bulk silicon circuits such as faster speed and improve radiation tolerance. One drawback to SOI is that parasitic bipolar induced latch-up/breakdown voltage levels severely limits the maximum supply voltage at which SOI circuits and devices can operate. When the parasitic device turns on, the SOI transistor cannot be switched off by changing the gate bias. What is described is a method whereby the operating voltage in which this effect occurs is significantly increased thus allowing circuit operation at reasonable power supply voltages. The method is to implant a neutral impurity ion such as krypton, xenon or germanium into the device (10) to form ion scattering centers. The size of the impurity atom must be much larger than the size of the silicon atom. The size difference generating a scattering center.