Method and device for detecting defects of patterns in microelectronic devices

Claim 1

An inspecting method for inspecting at least one planar object having a plurality of patterns which should be identical with each other, in order to detect defects of the patterns, comprising the steps of: placing said at least one object such that all of said plurality of patterns lie in a single plane; preparing an inspection mask having a plurality of translucent apertures; placing said inspection mask such that the inspection mask is adjacent and parallel to said at least one object; moving said inspection mask and said at least one object relative to each other in a plane parallel to said single plane, and positioning each of said apertures opposite mutually corresponding portions of said plurality of patterns, one after another in the same sequence; irradiating said at least one object and said inspection mask with radiant energy emitted in a direction substantially normal to said plane of relative movement thereof; converting the radiant energy that both passes through said apertures and is transmitted through or reflected by a surface of said at least one object, into electric signals by means of radiant energy converrting means; comparing the electric signals associated with said corresponding portions of said plurality of patterns, with each other, prior to obtaining said electric signals of all of said plurality of patterns; and determining that said corresponding portions of said patterns have a defect if said electric signals thereof differ from each other.

Claim 26

A device for detecting imperfections in a mask for x-ray lithography comprising: an inspection mask to select positions in an x-ray mask under inspection by means of an x-ray aperture array thereon, the size of said x-ray apertures being chosen equal to a design rule of said x-ray mask under inspection, with two-dimensional spacing of said apertures in the array corresponding to that of an elementary inspection area array in said x-ray mask under inspection; an alignment means for aligning a pair of regions of said x-ray mask under inspection with corrsponding positions of said x-ray aperture array, with an appropriate proximity gap; a two-dimensional positioning means for moving said inspection mask to an assigned position designated by a two-dimensional "E-address" within said elementary inspection area in accordance with said design rule, keeping said proximity gap invariable; a programmable driving means in said two-dimensional positioning means responsive to said E-address for covering an area equal to said elementary inspection area, with said x-ray aperture array covering the entire area of the x-ray mask under inspection; an x-ray source to irradiate said x-ray mask under inspection with enough x-ray flux for high speed comparison; a scintillation crystal having a size equal to said inspection mask to produce visible light energy within a given time interval, the total energy in said visible light being proportional to the x-ray energy passing through each of said x-ray apertures; an image intensifying means for amplifying said visible light from said scintillation crystal; a two-dimensional charge-coupled image sensing means to produce a serial signal proportional to the visible light intensity impinging on a light sensitive element array thereof, the two-dimensional spacing of said light sensitive element array corresponding proportionally to the spacing of said elementary inspection area array; an optical imaging means for focusing said visible light from an output plane of said image intensifying means upon said light sensitive element array of said two-dimensional charge-coupled image sensing means; a fast signal processing means to accomplish comparison between a pair of serial signals originating from each corresponding position of said pair of x-ray mask regions under inspection, and thus a series of "C-address" data which indicates location of an imperfection in accordance with the location of said light sensitive element of said two-dimensional charge-coupled picture sensing means, at an instant of material discrepancy between said serial signals, within one frame spacing of said two-dimensional charge-coupled picture sensing means corresponding to a fixed position of said inspection mask designated by an E-address; and a memory means having addresses according to the E-address, each address retaining an imperfection message as a series of the C-address data given by said fast signal processing means.

Claim 27

A device for detecting imperfections in a mask for x-ray lithography comprising: an inspection mask to select positions in an x-ray mask under inspection by means of an x-ray aperture array thereon, the size of said x-ray apertures being chosen equal to a design rule of said x-ray mask under inspection, with two-dimensional spacing of said apertures in the array corresponding to that of an elementary inspection area array in said x-ray mask under inspection; an alignment means for aligning a pair of regions of said x-ray mask under inspection with corrsponding positions of said x-ray aperture array, with an appropriate proximity gap; a two-dimensional positioning means for moving said inspection mask to an assigned position designated by a two-dimensional "E-address" within said elementary inspection area in accordance with said design rule, keeping said proximity gap invariable; a programmable driving means in said two-dimensional positioning means responsive to said E-address for covering an area equal to said elementary inspection area, with said x-ray aperture array covering the entire area of the x-ray mask under inspection; an x-ray source to irradiate said x-ray mask under inspection with enough x-ray flux for high speed comparison; a scintillation crystal having a size equal to said inspection mask to produce visible light energy within a given time interval, the total energy in said visible light being proportional to the x-ray energy passing through each of said x-ray apertures; an image intensifying means for amplifying said visible light from said scintillation crystal; a two-dimensional charge-coupled image sensing means to produce a serial signal proportional to the visible light intensity impinging on a light sensitive element array thereof, the two-dimensional spacing of said light sensitive element array corresponding proportionally to the spacing of said elementary inspection area array; an optical imaging means for focusing said visible light from an output plane of said image intensifying means upon said light sensitive element array of said two-dimensional charge-coupled image sensing means; a fast signal processing means to accomplish comparison between a pair of serial signals originating from each corresponding position of said pair of x-ray mask regions under inspection, and thus a series of "C-address" data which indicates location of an imperfection in accordance with the location of said light sensitive element of said two-dimensional charge-coupled picture sensing means, at an instant of material discrepancy between said serial signals, within one frame spacing of said two-dimensional charge-coupled picture sensing means corresponding to a fixed position of said inspection mask designated by an E-address; and a memory means having addresses according to the E-address, each address retaining an imperfection message as a series of the C-address data given by said fast signal processing means.