New device and method for simultaneous quasi-aplanatic imaging confocal detection of adjacent surfaces of semiconductor crystal grains

Abstract

The invention discloses a new method for simultaneous quasi-aplanatic imaging confocal detection of adjacent surfaces of semiconductor crystal grains. A detection device comprises a camera, a telecentric imaging lens, a semi-transparent and semi-reflective image combiner, the semiconductor crystal grains and a transparent object stage for bearing the semiconductor crystal grains which are sequentially arranged in a direction of a light path; a first right-angle transferring prism and a second right-angle transferring prism are respectively arranged on the light path between the semiconductor crystal grains and the semi-transparent and semi-reflective image combiner, the second right-angle transferring prism is positioned at a first side part of the optical axis of the telecentric imaging lens, the two right-angle surfaces of the two right-angle transferring prisms are respectively vertical to the light path, at least two surfaces of the semiconductor crystal grains are respectively imaged at different area positions on a sensor surface of the camera through the right-angle transferring prisms and the semi-transparent and semi-reflective image combiner by double light paths, and thedistance delta between the double images of the adjacent surfaces is adjustable.

Description

Technical field: [0001] The invention belongs to the fields of optical detection and machine vision, and in particular relates to a new device and method for simultaneous quasi-equal optical path confocal imaging detection of adjacent surfaces of semiconductor crystal grains. Background technique: [0002] In the application of machine vision imaging inspection, when the object to be inspected is large, a telecentric imaging lens with a suitable field of view is usually selected at one station to inspect one surface of the object; when the object to be inspected is small (such as semiconductor optoelectronic components) , in order to improve the detection speed and make full use of the effective field of view of the telecentric imaging lens, a technical solution of simultaneously detecting two surfaces of the object with one telecentric imaging lens on one station is adopted. [0003] The main technical problems to be solved by the device and method for simultaneous defect d...

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Problems solved by technology

[0008] In the scheme proposed by the applicant in previous patent applications (patent application numbers 201910207016.2, 201911247575.2), since the optical path difference △ of double-sided simultaneous imaging detection is related to the structural parameters (L1, L2), when the structural parameters are large, the method Inevitably there are certain limitations in use; the above two applications use a larger right-angle transfer prism and a large depth-of-field telecentric imaging lens to solve the resolution problems caused by simultaneous detection of adjacent surfaces and their optical path difference, such as Figure 1a , as shown in 1b, and the recently submitted patent application (application number 201911369253.5), the adjacent two sides also need to use a larger right-angle transfer prism (such as 30×30×15) and a smaller transfer prism ( such as 15x15×15), such as Figure 1c As shown, however, in order to obtain equal optical path imaging detection, it is necessary to carefully select relevant structural layout parameters when designing the optical path, which limits the freedom of optical path design, or increases the difficulty of implementing the detection system to a certain extent.

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