DETECTION OF DEFECT IN DIE

摘要

Generally discussed herein are systems, apparatuses, and methods that can detect a defect in a die. According to an example, a method can include transmitting a first beam of light with a wavelength and optical power configured to produce a reflected beam with at least one milli-Watt of power, linearly polarizing the first beam of light in a specific direction, circularly polarizing the linearly polarized light by a quarter wavelength to create circularly polarized light, directing the circularly polarized light to a device under test, linearly polarizing light reflected off the device under test by a quarter wavelength, or creating an image of the linearly polarized light reflected off the device under test.

主权项

1. An apparatus comprising:
a first light emitting element configured to transmit light with a wavelength and optical power configured to produce a reflected beam with at least one milli-Watt of power, wherein the wavelength of the light of the first light emitting element is one that passes through the die with less loss as compared to other wavelengths as determined by passing a broadband optical beam through bulk silicon and measuring the transmitted beam with an optical spectrum analyzer, and the optical power is set based on transmitting different optical intensity beams at the determined wavelength onto dies of varying thicknesses and measuring the transmitted power; a polarized beam splitter to receive the transmitted light from the light emitting element and transmit light that is linearly polarized in a specific direction; a collimator to receive the polarized light from the beam splitter and collimate the polarized light from the beam splitter to produce collimated polarized light; a quarter wave plate to receive the collimated polarized light from the collimator, circularly polarize the light incident thereon by a quarter wavelength, transmit the quarter wavelength collimated polarized light, receive quarter wavelength polarized light reflected from a device under test, linearly polarize the received quarter wavelength polarized light by another quarter wavelength to create half wavelength polarized light, and transmit the half wavelength polarized light; and a photo detector to receive half wavelength light reflected from the device under test and transmitted by the quarter wave plate.