Realization of numerical aperture 2.0 using a gallium phosphide solid immersion lens

1999 ◽  
Vol 75 (26) ◽  
pp. 4064-4066 ◽  
Author(s):  
Qiang Wu ◽  
G. D. Feke ◽  
Robert D. Grober ◽  
L. P. Ghislain
Author(s):  
Travis Eiles ◽  
Patrick Pardy

Abstract This paper demonstrates a breakthrough method of visible laser probing (VLP), including an optimized 577 nm laser microscope, visible-sensitive detector, and an ultimate-resolution gallium phosphide-based solid immersion lens on the 10 nm node, showing a 110 nm resolution. This is 2x better than what is achieved with the standard suite of probing systems using typical infrared (IR) wavelengths today. Since VLP provides a spot diameter reduction of 0.5x over IR methods, it is reasonable, based simply on geometry, to project that VLP using the 577 nm laser will meet the industry needs for laser probing for both the 10 nm and 7 nm process nodes. Based on its high level of optimization, including high resolution and specialized solid immersion lens, it is highly likely that this VLP technology will be one of the last optically-based fault isolation methods successfully used.


2005 ◽  
Vol 44 (5B) ◽  
pp. 3385-3387 ◽  
Author(s):  
Matthew Lang ◽  
Tom D. Milster ◽  
Takahisa Minamitani ◽  
Gregg Borek ◽  
David Brown

Author(s):  
Baohua Niu ◽  
Pat Pardy ◽  
Joe Davis ◽  
Mel Ortega ◽  
Travis Eiles

Abstract In this paper, we report on the first observation and study of two-photon absorption (TPA) based laser assisted device alteration (LADA) using a continuous-wave (CW) 1340nm laser. The study was conducted using LADA systems equipped with high numerical aperture (NA) liquid and solid immersion lens objectives on Intel’s 45 nm and 32 nm multiprocessor units (MPU) and test chips. The power densities achievable using these lenses are similar to those reported in the literature for TPA in silicon of CW 1455nm light [1]. We show that the induced photocurrent has a quadratic dependence on the input laser power, a key indicator of two-photon phenomenon. Our results imply that even when using 1340nm wavelength CW lasers, there is a potential for laser invasiveness with the high power densities achievable using high NA objectives. Laser induced damage of the DUT is also a possibility at these high power densities, particularly with the solid immersion lens (SIL). However, we show that the DUT damage threshold can be increased by reducing the DUT’s temperature. Finally, we present results demonstrating a >40% improvement in localization of critical timing faults using TPA based LADA, when compared to traditional 1064nm wavelength (single-photon absorption) LADA.


Author(s):  
M.S. Wei ◽  
H.B. Chong ◽  
S.H. Lim ◽  
C. Richardson

Abstract High resolution laser imaging, using high numerical aperture (NA) solid immersion lens (SIL) for backside fault isolation imposes stringent sample preparation requirements; as a result of the short focal length of SIL, a die must be thinned to a targeted thickness with less than a ±5 μm silicon thickness variation across the entire die. Flip chip packaged dice suffer from warpage due to various package sizes and substrate thicknesses. Such broad spectrums of part geometries pose a great challenge to meet such silicon planarity requirements. As relaxation of the packaged silicon during polishing causes the warpage profile to change dynamically and unpredictably throughout the thinning process, it has become an added challenge to meet the stringent sample preparation requirements. To overcome the stochastic nature of this problem, a two-step polishing recipe consisting of computer numerical control (CNC) mechanical milling and polishing processes has been developed to achieve sufficient silicon thickness uniformity to enable SIL imaging across an entire silicon chip as large as approximately 20 mm x 15 mm.


Author(s):  
P. Scholz ◽  
U. Kerst ◽  
C. Boit ◽  
T. Kujawa ◽  
T. Lundquist

Abstract The theoretical fundamentals of diffractive solid immersion lenses (dSILs) were revised and adapted to a new application: the direct single-step chemistry-assisted creation of binary dSILs in silicon with a focused ion beam (FIB). Current results were able to prove the general functionality of this technique, but also showed the limitations still present. These limitations were identified; the underlying problems were analyzed and were addressed by optimizing several aspects of the process. The presented dSIL has a diameter of 150 ìm and is created in 15 minutes of processing time. It is designed for a sample thickness of 70 µm, which can be well adjusted if needed. For this sample thickness, the theoretical numerical aperture is about 2.5, offering a significant improvement in resolution. Furthermore a comparison of diffractive and refractive solid immersion lenses is presented, both created in a similar process. Apart from general aspects of dSILs and rSILs (refractive SILs), details of the designs presented in this work are compared. This leads to the insight of which method (dSIL or rSIL) has its advantages for which type of application.


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