System and method for determining probing locations on IC
AssigneeCredence Systems Corporation
InventorsHitesh Suri, Cathy Kardach
Life of this patent
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Abstract
An apparatus and method for tracing back a probing location to identify the circuit element being probed on a device under test (DUT). The coordinates of the irregularity on the DUT are used to trace back to the logic cone to decipher the root-cause of the irregularity. The Def and Lef files are interrogated using the coordinates to obtain the cell and net data to enable the investigation. Additionally, a schematic viewer is used to investigate the logic cone to potential root-causes for the irregularities.
Claims29
A method for identifying elements on a device under test (DUT) that are suspect of causing irregularities manifested as photoemission locations on the DUT, comprising:
- a. receiving spatial coordinates of the photoemissions on the DUT;
- b. interrogating a Def file to locate Def entries matching said spatial coordinates and obtaining from said Def entries cell instance name and cell type, of corresponding cells;
- c. interrogating schematic viewer to locate schematic entries matching said cell instance name for each of said cell names.
A method for identifying elements on a device under test (DUT) that are suspect of causing irregularities manifested as photoemission locations on the DUT, comprising:
- a. receiving spatial coordinates of the photoemissions on the DUT;
- b. interrogating a Def file to locate Def entries matching said spatial coordinates and obtaining from said Def entries cell instance name and cell type, of corresponding cells;
- c. interrogating Lef file to obtain entries corresponding to said cell types to obtain cell width, cell height and cell pin data.
A system for probing a microchip device under test (DUT), comprising:
- an adapter for mounting the DUT thereupon;
- a prober having probing axis;
- a movable stage providing relative motion between the DUT and the prober so as to align the probing axis with selected locations on the DUT;
- a controller controlling the stage to thereby place said prober so that said probing axis correspond to determinable coordinates on said DUT;
- a processor preprogrammed to perform the steps:
- a. receive said coordinates;
- b. interrogating a Def file to locate Def entries matching said spatial coordinates and obtaining from said Def entries cell instance name and cell type, of corresponding cells;
- c. interrogating a Lef file to obtain entries corresponding to said cell types to obtain cell width, cell height and cell pin data.
A method for identifying elements on a device under test (DUT) that are suspect of causing irregularities manifested as photoemission locations on the DUT, comprising:
- a. converting Lef and Def files into a binary form to obtain a binary Lef/Def database;
- b. receiving spatial coordinates of the photoemissions on the DUT;
- c. interrogating the Def/Def database to locate entries matching said spatial coordinates and obtaining from said entries cell instance name and cell type, of corresponding cells;
- d. interrogating schematic viewer to locate schematic entries matching said cell instance name for each of said cell names.
Dependencies are inferred from the claim text.