In-line electrical monitor for measuring mechanical stress at the device level on a semiconductor wafer
AssigneeInternational Business Machines Corporation
InventorsEdward D. Adams, Arne W. Ballantine, Richard S. Kontra, Alain Loiseau, James A. Slinkman
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Abstract
A method is presented for measuring and monitoring the mechanical stress at the device level which occurs intrinsically during the fabrication process or which is induced via extrinsic means. The method applies the fact that the current-voltage (I-V) characteristics of a diode change as the diode is subjected to mechanical stress. The method is applicable to monitoring stress at the microscopic and device levels at various stages in the semiconductor wafer fabrication process. Apparatus for implementing the method is also presented.
Claims18
A stress monitoring set comprising:
- at least one pair of diode devices, said pair comprising a first device and a second device, wherein said first device is a reference device, and said second device is a measurement device wherein each measurement device includes:
- a diode structure formed in a semiconductor material;
- and
- a non-diode structure including a plurality of isolation trenches surrounding the diode structure.
A structure for measuring stress in a semiconductor device comprising:
- a pn diode formed on the surface of a semiconductor device, said diode being bounded by a first isolation region having predetermined dimensions;
- a diffusion region formed on the surface of the device, said diffusion region being bounded by a second isolation region having the same dimensions as the first isolation region;
- and
- contacts formed on said diode and diffusion region for passing current through the diode and through said diffusion region.
A stress monitoring unit comprising:
- a semiconductor material forming a base structure, said base structure containing a diode structure and a non-diode structure;
- said diode structure formed in the semiconductor material;
- said non-diode structure including a plurality of isolation trenches surrounding the diode structure, said isolation trenches being filled with a dielectric material;
- a system for applying an electrical potential across the diode structure, thereby inducing a diode current to flow through the diode structure;
- a system for measuring the diode current;
- and
- a system for translating the amount of diode current measured into dimensional units representing the stress on the base structure.
A stress monitoring system for monitoring mechanical stress in a semiconductor substrate containing trench isolation regions comprising:
- a semiconductor material forming a base structure, said base structure containing a diode structure and a non-diode structure;
- said diode structure formed in the semiconductor material;
- said non-diode structure including a plurality of isolation trenches surrounding the diode structure, said isolation trenches being filled with a dielectric material;
- a system for applying an electrical potential across the diode structure, thereby inducing a diode current to flow through the diode structure;
- a system for measuring the diode current;
- and
- a system for translating the amount of diode current measured into dimensional units representing the stress on the base structure.
Dependencies are inferred from the claim text.