ONLINE TEST STRUCTURE FOR RESIDUAL STRESS OF POLYCRYSTALLINE SILICON MATERIAL

摘要

An online test structure for the residual stress of a polycrystalline silicon material, comprising three deflecting pointers of polycrystalline silicon having substantially the same structure, the three deflecting pointers of polycrystalline silicon being arranged in a delta shape with all pointers pointing to the centre. Each deflecting pointer comprises a horizontal driving beam (101, 103, 105), a pointer (102, 104, 106) perpendicular to the driving beam (101, 103, 105), and two anchoring regions fixed on a substrate, the two anchoring regions (107, 108, 109, 110, 111, 112) fixing one end of the driving beam (101, 103, 105) and one end of the pointer (102, 104, 106) respectively. By controlling the initial direction of deflection of the pointer under the action of the residual stress, the maintenance and change in distance can effectively reflect the amount and properties of the residual stress. During testing, heat driving is utilised, and the measured parameters are the electrical resistance of the front and rear driving beams for heat driving. The measurement and calculation do not require a thermal expansion co-efficient, avoiding the effect of errors in the measurement results during online testing of the thermal expansion co-efficient.