Wafer alignment and positioning apparatus for chip testing by voltage contrast electron microscopy
AssigneeHughes Aircraft Company
InventorJohn W. Reeds
Life of this patent
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Abstract
An apparatus for use in testing IC chips on a semiconductor wafer is disclosed that allows the wafer and an electrical probe to be independently positioned and then clamped together and moved as a single unit when they are in alignment. This permits a chip on a wafer to be supplied with power and tested electronically while any desired area of the chip can be positioned in the field of view of a scanning electron microscope for examination, such as with a voltage-contrast secondary-electron detector. Use of the disclosed apparatus will greatly facilitate and simplify the testing of unbonded chips on semiconductor wafers.
Claims15
Apparatus for coordinating the movement of a semiconductor wafer with an electrical tests probe for testing integrated circuit chips on the wafer while the circuits are powered, comprising:
- means for aligning and bringing into contact said test probe with a chip on a wafer;
- a clamp for clamping said test probe with a wafer;
- and
- means for moving said test probe and a wafer as a unit while said test probe and a wafer are clamped together, the means for moving itself comprising an aspect of the testing of a chip.
Apparatus for coordinating the movement of a semiconductor wafer with an electrical test probe for testing integrated circuit chips on the wafer while the circuits are powered, comprising:
- means for supporting said test probe;
- means for supporting a wafer;
- means for aligning and bringing into contact said test probe with a chip on a wafer;
- a clamp for clamping said test probe with a wafer;
- and
- means for moving said test probe and a wafer as a unit while said test probe and a wafer are clamped together, the means for moving itself comprising an aspect of the testing of a chip.
Apparatus for coordinating the movement of a semiconductor wafer with an electrical test probe for testing integrated circuit chips on the wafer while the circuits are powered, comprising:
- an electrical test probe;
- means for moving the test probe;
- means for moving a semiconductor wafer, the means for moving itself comprising an aspect of the testing of a chip;
- and
- clamping means for clamping said probe moving means and said wafer moving means so that a wafer and test probe can be moved as a unit during active testing, and for disconnecting the probe moving means and the wafer moving means so that a wafer and test probe can be moved independently when a wafer is not being tested.
Apparatus for coordinating the movement of a semiconductor wafer with an electrical test probe for testing integrated circuit chips on the wafer while the circuits are powered, comprising:
- a wafer positioning stage having a top plate adapted to move in a first plane;
- wafer mounting means on said wafer positioning stage for mounting a wafer;
- X drive means for controlling the movement of said wafer positioning stage in one direction in said first plane, drivingly connected to said wafer positioning stage;
- Y drive means for controlling the movement of said wafer positioning stage in a second direction in said first plane, drivingly connected to said wafer positioning stage;
- the X and Y drive means themselves comprising an aspect of the testing of a chip;
- a probe positioning stage adapted to move in a second plane parallel to said first plane;
- a probe with a plurality of electrical contact fingers mounted on said probe positioning stage;
- Z drive means for controlling the vertical movement of said probe positioning stage, drivingly connected to said probe positioning stage;
- and
- clamping means for clamping said probe and wafer positioning stages so that a wafer and test probe can be moved as a unit during active testing, and for disconnecting the test probe and the wafer positioning stages so that a wafer and test probe can be moved independently when a wafer is not being tested.
Dependencies are inferred from the claim text.