National Semiconductor Corporation

Zachary Joshua Gemmill

Kevin C Weaver

Steven Jacobson

William Ng

Duc Huu Nguyen

Usharani Bhimavarapu

The time required to perform a passive voltage contrast test of an area of interest of a layer of interest is substantially reduced by digitizing a passive voltage contrast image to form contrast data that represents the image, and comparing the contrast data to computer aided design (CAD) data that defines the semiconductor device.

Method of reducing the time required to perform a passive voltage contrast test

Features of non-vacuum AC/DC probe systems are combined with features of the DC vacuum chamber testers to provide an AC/DC probe system that can be used in a vacuum environment, such as a SEM vacuum chamber. Features of the DC vacuum chamber tester are modified to include new op-amp circuitry that provides the AC/DC testing functionality of the non-vacuum chamber systems, resulting in an AC/DC probe system that can be used in a vacuum environment.

Vacuum chamber AC/DC probe

In an IC structure and method for debugging or adjusting the parameters of an IC circuitry, edit structures are formed in the IC device and are connected to desired portions of the IC circuitry buy forming vias through the passivation layer overlying the top metal layer and forming metal interconnects.

Built-in design edit structures

Point-by-point image contrast values are generated from secondary electron collection during unbiased electron or ion beam bombardment of an integrated circuit (IC) in a vacuum environment to quantify the physical and electrical integrity of connections within the device. These values are stored for each type of circuit cell under standard conditions to quantify and check the performance of individual cells on the device.

E-beam voltage potential circuit performance library

The thickness of a semiconductor wafer is non-destructively measured using infrared (IR) microscopy. The wafer is placed on a stage. A distance between the stage and a detector is then varied so that a first image of the wafer is focused on the detector. When focused, a first separation distance is measured. The distance between the stage and the detector is again varied so that a second image is focused on the detector. When again focused, a second separation distance is measured. The difference between the first and second separation distances is then determined and multiplied by the refractive index of light in silicon.

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Mountain View, CA, United States of America

Zachary Joshua Gemmill