Measuring back-side voltage of an integrated circuit
AssigneeNPTest, LLC
InventorsChristopher Shaw, Chun-Cheng Tsao, Theodore R. Lundquist
Life of this patent
Estimating the term…
Abstract
Methods for integrated circuit diagnosis, characterization or modification using a charged particle beam. In one implementation, the bulk silicon substrate of an integrated circuit is thinned to about 1 to 3 μm from the deepest well, a voltage is applied to a circuit element that is beneath the outer surface of the thinned substrate. The applied voltage induces an electrical potential on the outer surface, which is detected as a surface feature on the outer surface by its interaction with the charged particle beam.
Claims25
A method, comprising:
- applying a voltage to a circuit element of an integrated circuit having a thinned substrate layer, the circuit element being beneath an outer surface of the thinned substrate layer, the applied voltage inducing an electrical potential on the outer surface;
- and
- detecting the electrical potential as a surface feature on the outer surface.
A method for determining the location of a circuit element in an integrated circuit, comprising:
- applying a voltage to a circuit element of an integrated circuit having a thinned substrate layer, the circuit element being beneath an outer surface of the thinned substrate layer, the applied voltage inducing an electrical potential on the outer surface;
- obtaining a voltage contrast image by detecting electrical potentials over a region of the outer surface;
- and
- using the voltage contrast image to determine the location of the circuit element.
A method, comprising:
- determining the location of a circuit element in an integrated circuit by applying a voltage to the circuit element, the circuit element being disposed on a thinned substrate and located beneath an outer surface of the thinned substrate, the applied voltage inducing an electrical potential on the outer surface, and using an electron beam prober to detect the electrical potential as a surface feature on the outer surface;
- and
- inducing a current in the circuit element through the thinned substrate with an electron beam from the electron beam prober.
Dependencies are inferred from the claim text.