Micro photoluminescence imaging with optical filtering
AssigneeSEMILAB Semiconductor Physics Laboratory Co., Ltd.
InventorsZoltan Tamas Kiss, Laszlo Dudas, Gyorgy Nadudvari, Nicolas Laurent, Lubomir L. Jastrzebski
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Abstract
A method that includes: illuminating a wafer with excitation light having a wavelength and intensity sufficient to induce photoluminescence in the wafer; filtering photoluminescence emitted from a portion of the wafer in response to the illumination; directing the filtered photoluminescence onto a detector to image the portion of the wafer on the detector with a spatial resolution of 1 μm×1 μm or smaller; and identifying one or more crystallographic defects in the wafer based on the detected filtered photoluminescence.
Claims18
A method comprising:
- illuminating a wafer comprising a crystalline material with excitation light having a wavelength and intensity sufficient to induce both photoluminescence from band-to-band transitions in the crystalline material and photoluminescence from crystallographic defects in the crystalline material;
- filtering excitation light reflected from the portion of the wafer and photoluminescence emitted from a portion of the wafer in response to the illumination to provide filtered photoluminescence, wherein the filtering substantially removes the photoluminescence from band-to-band transitions in the crystalline material from the filtered photoluminescence;
- directing the filtered photoluminescence onto a multi-element detector to image the wafer on the detector;
- identifying one or more crystallographic defects in the crystalline material based on the detected filtered photoluminescence;
- and
- determining a depth of the one or more crystallographic defects relative to a surface of the wafer based on the detected filtered photoluminescence.
A method for identifying crystalline defects in a wafer comprising an array of integrated circuit elements each isolated from an adjacent integrated circuit element by a corresponding trench, the method comprising:
- illuminating the wafer with excitation light having a wavelength and intensity sufficient to induce both photoluminescence from band-to-band transitions in a crystalline material of the wafer and photoluminescence from crystallographic defects in the crystalline material;
- filtering excitation light reflected from the portion of the wafer and photoluminescence emitted from a portion of the wafer in response to the illumination to provide filtered photoluminescence, wherein the filtering substantially removes the photoluminescence from band-to-band transitions in the crystalline material from the filtered photoluminescence;
- directing the filtered photoluminescence onto a multi-element detector to image the wafer on the detector;
- identifying one or more crystallographic defects in the crystalline material at a wall of a trench separating two of the integrated circuit elements based on the detected filtered photoluminescence.
Dependencies are inferred from the claim text.