Method for aligning laser beam with fuses in integrated circuit
AssigneeIntel Corporation
InventorsRonald J. Smith, John P. Dishaw
Life of this patent
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Abstract
A method is disclosed for aligning a laser beam to an integrated circuit. A pair of generally parallel spaced-apart fusible links are formed on the circuit. The laser beam is positioned to a site known to be to one side of one link. Then the beam is stepped towards the links until the link is blown. The beam is then moved a predetermined distance so that it is positioned to one side of the other link. This beam is then stepped toward this link in the opposite direction until it is blown. The midpoint between the links can then be readily computed.
Claims13
A method for determining the position of a laser beam on an integrated circuit comprising the steps of:
- forming a first and second spaced-apart, generally parallel links in said circuit;
- positioning said laser beam on said circuit to a position known to be spaced-apart from said first link;
- changing the relative position of said laser beam and said first link by movement in a first direction such that the distance between said first link and laser beam is decreased;
- monitoring the electrical characteristics of said first link to determine when said electrical characteristics of said first link are substantially altered by said laser beam;
- positioning said laser beam on said circuit to a position known to be spaced-apart from said second link;
- changing the relative position of said laser beam and said second link by movement in a second direction opposite to said first direction such that the distance between said second link and said laser beam is decreased;
- monitoring the electrical characteristics of said second link so as to determine when said electrical characteristics of said second link are substantially altered by said laser beam;
- whereby by knowing the position of said laser beam on said circuit when the electrical characteristics of said first and second links are altered by said laser beam, the precise position of said laser beam on said circuit is determined.
A method for determining the position of a moveable laser beam on an integrated circuit which circuit is mounted on a stationary surface, comprising the steps of:
- forming a first and second spaced-apart, generally parallel, links in said circuit which links are electrically coupled in parallel;
- moving said beam to a first position where it is known that said beam will be spaced-apart from said first link;
- monitoring the resistance of said links while moving said laser beam in a first direction towards said first link so as to determine a first position at which said resistance of said links changes because of at least partial destruction of said first link by said beam;
- moving said beam to a position where it is known that said beam will be spaced-apart from said second link;
- monitoring the resistance of said links while moving said beam towards said second link so as to determine a second position at which said resistance of said links changes because of at least partial destruction of said second link by said beam, said movement of said beam being made in a second direction opposite said first direction;
- whereby the precise location of said laser beam in said first and second direction is readily determined from said first and second positions.
Dependencies are inferred from the claim text.