Emission microscopy apparatus and method

Claim 1

Emission microscopy apparatus for detecting light emitted from defects in dielectric layers of integrated circuit devices (10) in response to test vector signals applied to input and output terminals of the integrated circuit device (10), comprising: - mounting means for holding the device under test (10) to be inspected; - optical means (11) including macro optic means (30) having a high numerical aperture for obtaining global optical images of said device under test (10) and including micro optic means (40) for alternatively obtaining micro optical images of sub-areas of said device under test (10); - primary camera means (13) for converting said optical images into analog electronic signals, said camera means (13) including light intensifier means (12) and being capable of integrating the analog electronic signals; - video image signal processing means (14) for processing said analog electronic signals; and - video image display means (15) for displaying signals processed by said video image processing means (14).

Claim 4

The apparatus of any of claims 1 or 2, wherein said mounting means and said optical means (11) are moveable with respect to each other automatically under programmed control by said signal processing means (14).

Claim 5

The apparatus of any of claims 1 to 3, wherein said mounting means include a socket adaptor module (23) with local switches (24) and auxiliary signal input means (25) for applying selected test vector voltages to said input and output terminals.

Claim 6

The apparatus of any of claims 1 to 4, wherein said mounting means includes means (26) to mount a second device under test adjacent said first mentioned device under test (10), and said module (23) includes means for applying test vectors to said second device under test.

Claim 7

The apparatus of any of claims 1 to 5, wherein said mounting means includes wafer chuck means, probe means, and wherein both said mounting means and said optical means (11) are moveable with respect to each other automatically under programmed control by said signal processing means (14).

Claim 8

The apparatus of any of claims 1 to 6, wherein said mounting means includes stimulator module means (120) for programmably applying selected test vectors to input/output terminals of a device under test (10) inserted into said socket adaptor module (23).

Claim 10

The apparatus of any of claims 7 or 8, wherein said stimulator module (120) is programmable to apply selected test vectors in a selected order through said stimulator module (120) to a device under test (10).

Claim 11

The apparatus of any of claims 1 to 9, further including computer aided design interface means for said image signal processing means (14) to access integrated circuit composite layout images from a computer aided design system (125).

Claim 12

The apparatus of any of claims 1 to 10, further including auxiliary camera means (21) for providing a display image to supplement the image provided by said primary camery means (13).

Claim 13

The apparatus of any of claims 1 to 11, wherein said micro optic means (40) includes a plurality of lens means having magnification powers in the range between 10 and 100 times, and is engageable in the optical axis of said primary camera (13) by the computer (14).

Claim 14

The apparatus of any of claims 1 to 12, further including illumination means (29) for illuminating said device under test (10) at light intensity levels automatically controlled by said computer means (14).

Claim 15

The apparatus of any of claims 1 to 13, wherein said display means (15) includes storage means (19).

Claim 17

The apparatus of any of claims 14 or 15, wherein said storage means (19) includes floppy disk storage means (127).

Claim 18

The apparatus of any of claims 14 to 16, wherein said storage means (19) includes video image printer means (128).

Claim 19

The apparatus of any of claims 1 to 17, wherein opera­tions of said system are controlled by said image processing means (14) under the control of mouse input means.

Claim 20

A method of detecting light emitted from defects in dielectrics located at unknown coordinates in an inte­grated circuit device (10), comprising the steps of: - obtaining a reference image of said device; - forming a background image of collectable noise; - applying electrical voltages to selected terminals of the integrated circuit device (10) so as to cause light to be emitted at the locations of defects contained therein; - forming an emitted light image of said integrated circuit including the light emitted from defects contained therein; - forming a difference light image of said integrated circuit by subtracting said background image from said emitted image; - processing said difference image to remove noise and to produce a processed macro difference image; - superimposing said processed macro difference image onto said reflected image to form a super­imposed image; - identifying defect bright spots on said superimposed image; - compiling a list of coordinates of said bright spots; - replacing said macro lens (30) with a micro lens (40); - moving the axis of said micro lens (40) over a first set of coordinates from said list; - forming a difference image of the local area in a window around said set of coordinates; - processing said difference image to remove noise and to produce a processed micro difference image; - superimposing said processed difference image over said micro-reflected image; and - comparing said superimposed image to a reference image of said integrated circuit (10) to locate coordinates of said defect, more precisely relative to said integrated circuit (10).

Claim 21

A method of detecting light emitted from defects in dielectrics located at unknown coordinates in an inte­grated circuit device (10), comprising the steps of: - obtaining a reference image of said device; - forming a background image of collectable noise; - applying electrical voltages to selected terminals of the integrated circuit device (10) so as to cause light to be emitted at the locations of defects contained therein; - forming an emitted light image of said integrated circuit including the light emitted from defects contained therein; - forming a difference light image of said integrated circuit by subtracting said background image from said emitted image; - processing said difference image to remove noise and to produce a processed macro difference image; - superimposing said processed macro difference image onto said reflected image to form a super­imposed image; - identifying defect bright spots on said superimposed image; - compiling a list of coordinates of said bright spots; - replacing said macro lens (30) with a micro lens (40); - moving the axis of said micro lens (40) over a first set of coordinates from said list; - forming a difference image of the local area in a window around said set of coordinates; - processing said difference image to remove noise and to produce a processed micro difference image; - superimposing said processed difference image over said micro-reflected image; and - comparing said superimposed image to a reference image of said integrated circuit (10) to locate coordinates of said defect, more precisely relative to said integrated circuit (10).

Claim 23

The method of any of claims 19 or 20, wherein said step of processing includes filtering said image by spacial characteristics discrimination such as "erosion".

Claim 24

The method of any of claims 19 to 21, wherein said step of processing includes performing context dis­crimination on said difference image.

Claim 25

The method of any of claims 19 to 22, wherein said step of processing includes the step of "painting" said difference image.

Claim 27

The method of any of claims 19 to 24, wherein said step of processing is programmably automatically per­formed.