Fujitsu Corporation

Youji Nishiyama

Hiroyuki Tsukahara

Fumiyuki Takahashi

Takashi Fuse

Yoshitaka Oshima

A method of inspecting bumps provided on a surface of an object to be inspected includes the steps of: (a) irradiating a first irradiation beam on said object in an oblique direction and (b) imaging a first reflected beam from said object so as to obtain a first reflection image including a first reflection region and a height data of said bump corresponding to said first regular reflection region produced by a part of the first reflected beam reflected near an apex of the bump. The method further includes the steps of (c) shifting a position of said first regular reflection region in said first reflection image in accordance with a value derived from said height data and said predetermined angle, (d) extracting said first regular reflection region within a predetermined region from said first reflection image after said step c), and (e) detecting a height of said bump based on said height data corresponding to the extracted first regular reflection region. Also disclosed is an apparatus for performing the disclosed method.

Method and apparatus for inspecting bumps and determining height from a regular reflection region

The bump height is measure din a sample area on a wafer, the bump height distribution on the wafer is estimated on the bases of the measured value, the portion where the estimated height distribution is out of a predetermined range is determined as an inspection area, and the bump height is measured in the inspection area, and a chip area having a bump height out of a predetermined range is judged to be defective. Data of the inspection areas and inspection results are accumulated, and the inspection density is renewed on the basis of the accumulated data. In another method, the inspection area is divided into rectangular blocks so that each block has a width of approximately equal to a light beam scanning length and a distance between any adjacent bumps in the feeding direction is less than a predetermined value, feeding path being perpendicular to the scanning direction. Block feed time and between-block feed time are calculated, a whole feeding path whose total feed time of the block and between-block feed time are minimum is found, and bump height is measured with receiving reflected light from the bump while feeding along the found feeding path.

Method and apparatus for visual inspection of bump array

The object of the present invention is to provide a height measurement device that can accurately measure the height of an object to be measured, and that can easily and precisely adjust the focal point of an optical system. According to the present invention, a height measurement device, which forms an image of a light point generated by a light source on a surface of a measured object via an irradiation side focusing lens, which forms an image of the formed image of the light point on a light point position detector via a light reception side focusing lens, and measures a height of the measured object according to the light point position on the light point position detector, comprises: a stage perpendicularly movable with the measured object mounted thereon; a camera for obtaining a light point image formed on a target face on the stage; and a controller for detecting a position of the stage or of the radiation focusing lens as a focal point, at which a light quantity on a predetermined pixel in the light point image obtained by the camera becomes a maximum level, while moving the stage or the irradiation side focusing lens.

Height measurement device and height measurement method

The present invention is a method for inspecting height, scanning the surface of a subject item having zones of different reflectance with incident light of a prescribed intensity, causing the reflected light from the surface to be imaged with means for detecting light spot positions, and detecting the height of said surface from the light spot position which was imaged, said method comprising: a step of scanning, in a second zone with low reflectance surrounding a first zone with high reflectance with a first intensity of incident light, which is low to the degree that said means for detecting light spot positions is not saturated even with said high reflectance; and a step of scanning, if it is detected that the quantity of light of the imaged light of said reflected light exceeds a prescribed threshold value, with an appropriate second intensity of incident light found from said intensity of incident light and said detected quantity of light at the time of the preceding scan.

Growing community of inventors

Kawasaki, Japan

Youji Nishiyama