System and apparatus for using test structures inside of a chip during the fabrication of the chip
First Claim
1. A method for evaluating a fabrication of a semiconductor wafer, the method comprising:
- locating one or more test structures in a die on the wafer, wherein each of the one or more test structures is activatable to exhibit electrical activity that is indicative of a quality metric of the fabrication sequence and/or of a particular fabrication step or sequence in the fabrication;
subjecting the wafer to at least one of a plurality of fabrication processes that comprise the fabrication;
activating the one or more test structure with a power signal and a test signal generated from within the die;
measuring electrical activity generated from the at least one or more test structures in order to determine a performance parameter value of one or more test structures; and
using a correlation between the particular fabrication step or sequence of the die and the performance parameter value of each of the one or more test structures to evaluate the fabrication.
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Accused Products
Abstract
The fabrication of the wafer may be analyzed starting from when the wafer is in a partially fabricated state. The value of a specified performance parameter may be determined at a plurality of locations on an active area of a die of the wafer. The specified performance parameter is known to be indicative of a particular fabrication process in the fabrication. Evaluation information may then be obtained based on a variance of the value of the performance parameter at the plurality of locations. This may be done without affecting a usability of a chip that is created from the die. The evaluation information may be used to evaluate how one or more processes that include the particular fabrication process that was indicated by the performance parameter value was performed.
43 Citations
29 Claims
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1. A method for evaluating a fabrication of a semiconductor wafer, the method comprising:
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locating one or more test structures in a die on the wafer, wherein each of the one or more test structures is activatable to exhibit electrical activity that is indicative of a quality metric of the fabrication sequence and/or of a particular fabrication step or sequence in the fabrication;
subjecting the wafer to at least one of a plurality of fabrication processes that comprise the fabrication;
activating the one or more test structure with a power signal and a test signal generated from within the die;
measuring electrical activity generated from the at least one or more test structures in order to determine a performance parameter value of one or more test structures; and
using a correlation between the particular fabrication step or sequence of the die and the performance parameter value of each of the one or more test structures to evaluate the fabrication. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. An assembly for evaluating a fabrication of a semiconductor wafer, wherein the semiconductor wafer includes one or more test structures positioned on wafer at various locations including within at least one die of the wafer, and wherein the assembly comprises:
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one or more energy sources located externally to the semiconductor wafer;
a control system that is configured to control the one or more energy sources into directing energy onto one or more energy receiving elements on one or more die of the wafer, wherein the energy is suitable to activate the one or more test structures;
a detector system comprising one or more detectors, the detector system being configured to measure electrical activity from the one or more test structures that are activated by the direction of energy from the one or more energy sources in order to determine a performance parameter value for each of the one or more test structures;
a data processing unit that interprets electrical activity detected by the detector system and identifies a correlation between the performance parameter value and one or more fabrication steps or sequences of the fabrication. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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Specification