Mechanical sensors based on laser-recrystallized SOI structures

Application of microzone laser recrystallization in the technology of microelectronic mechanical sensors is considered. Recent results concerning theoretical and experimental studies of recrystallized polycrystalline silicon on insulator resistors, improvement of pressure-sensor performance and creation of microelectronic sensors of force and acceleration are reported. It is shown theoretically and proved experimentally that dopant impurity (boron) concentrations of 1 X 10(18)-1 X 10(19) cm(-3) are the most advisable to apply laser recrystallization for the improvement of poly-Si resistors and mechanical sensors based on them. At dopant levels of 1 X 10(18)-5 X 10(18) cm(-3) the gauge factor increases 1.5-1.7 times due to the laser recrystallization, whilst the temperature characteristics of poly-Si resistors (temperature coefficient of resistivity and temperature coefficient of the gauge factor) decrease. Advantages of the developed mechanical sensors are high-temperature operating range, possibility to select the temperature coefficients by the choice of doping concentrations in polysilicon layers and reproducibility of the sensor fabrication process.