Control of residual stress of polysilicon thin films by heavy doping in surface micromachining
- 9 December 2002
- conference paper
- Published by Institute of Electrical and Electronics Engineers (IEEE)
Abstract
Control of residual stress of polysilicon thin films for use in surface micromachining was experimentally studied. It was found that stress can be controlled by fairly heavy doping and subsequent annealing. Polysilicon films with lower than 50 ppm tensile and -50 ppm compressive strain were fabricated as measured from micromachined test structures. Very low tensile strains of less than 100 ppm were obtained with As/sup +/ implantation doses on the order of 1-3*10/sup 16/ cm/sup -2/ and annealing temperatures of 1050 degrees C. Strains as low as 15-30 ppm were achieved. The problem of sticking of structures to the substrate after wet etching of sacrificial oxide was observed and circumvented.Keywords
This publication has 7 references indexed in Scilit:
- Thin films for micromechanical sensorsJournal of Vacuum Science & Technology A, 1990
- Design properties of polycrystalline siliconSensors and Actuators A: Physical, 1990
- Fabrication of micromechanical devices from polysilicon films with smooth surfacesSensors and Actuators, 1989
- Fine-grained polysilicon films with built-in tensile strainIEEE Transactions on Electron Devices, 1988
- A simple technique for the determination of mechanical strain in thin films with applications to polysiliconJournal of Applied Physics, 1985
- Stress Effects in Boron‐Implanted Polysilicon FilmsJournal of the Electrochemical Society, 1984
- Effect of phosphorus doping on stress in silicon and polycrystalline siliconJournal of Applied Physics, 1983