High-contrast microscopy of semiconductor and metal sites in integrated circuits by detection of optical feedback

Abstract

High-contrast microscopy of semiconductor and metal sites in integrated circuits is demonstrated with laser-scanning confocal reflectance microscopy, one-photon (1P) optical-beam-induced current (OBIC) imaging, and detection of optical feedback by means of a commercially available semiconductor laser that also acts as an excitation source. The confocal microscope has a compact in-line arrangement with no external photodetector. Confocal and 1P OBIC images are obtained simultaneously from the same focused beam scanned across the sample plane. Image pairs are processed to generate exclusive high-contrast distributions of semiconductor, metal, and dielectric sites in a GaAs photodiode array sample.

Lock On!

“…1b). Previous research utilised simple post-processing of this image pair to discriminate metallic and semiconductor sites in 3D and localise defects within the differentiated regions [1,2].…”

Measurement of microsurface topography using a self-mixing optical configuration

“…[2][3][4][5] The SMI-based imaging can be classified into two classes. In one class, the LD is set to operate at a steady state, [6][7][8][9] using SMI in a confocal microscope configuration. The laser is operated at a constant bias current.…”

Confocal laser feedback microscopy for in‐depth imaging applications

“…In the past few decades, LFI has been extensively employed in general remote sensing applications such as metrology, profilometry, and vibrometry [7,8,10]. Using LFI technique in optical laser scanning microscopy has been successfully demonstrated [2,[11][12][13][14][15]. In some of the early studies, it was suggested that despite the non-linearities in the sensing process, which can be related to the dynamics of semiconductor lasers under the feedback regime, CLFM possesses all the functionality of CLSM [2].…”

“…Surface microscopy of biological cells has also been demonstrated [14,15]. Furthermore, the possibility of depth sectioning has been investigated to some extent by imaging the surface at different axial depths [2,13]. Although CLFM has been used for surface microscopy of objects and for micro-profilometry [2,[11][12][13]15], its in-depth (from deep within a scattering sample) microscopic imaging potential for visualisation of micro-structures has not been fully explored to date.…”

“…Furthermore, the possibility of depth sectioning has been investigated to some extent by imaging the surface at different axial depths [2,13]. Although CLFM has been used for surface microscopy of objects and for micro-profilometry [2,[11][12][13]15], its in-depth (from deep within a scattering sample) microscopic imaging potential for visualisation of micro-structures has not been fully explored to date. The existing in-depth LFI imaging work is on larger objects such as a coin immersed in milk [16] or a needle tip in onion [17].…”