One of the areas that can store charge in a MOS switch is the silicon substrate itself. Since an insulator act as a substrate, the junction capacitance will be eliminated and the MOS transistor will operate faster. The body effect problems and latch up problems are eliminated in SOI. One of the first early applications of SOI has been in memories for space application; since the memories built on SOI were perceived to be more resistant to soft error rate. Soft error rate refers to upset of data in the memory by cosmic rays and background radioactive material. Due to the absence of wells, a closer transistor packing can be achieved in SOI. The major disadvantages of SOI are that it presents lower gains and higher cost. Protecting diodes at inputs cannot be realized in SOI due to absence of silicon substrates.