A Combination Continuous Wave and Pulse Laser Assisted Chemical Etching Processes through Encapsulated IC Packaging

2015 ◽  
Author(s):  
Matthew M. Mulholland ◽  
Scott Silverman
Keyword(s):  
Integrated Circuits ◽  
Pulse Laser ◽  
Chemical Etching ◽  
Focused Ion Beam ◽  
Continuous Wave ◽  
Ion Beam ◽  
Packaging Materials ◽  
Local Approach ◽  
Solder Bumps ◽  
Ic Packaging

Abstract Post silicon validation techniques specifically Focused Ion Beam (FIB) circuit editing and Failure Analysis (FA) require backside sample preparation on Integrated Circuits (IC). Although these preparation techniques are typically done globally across the encapsulated and silicon packaging materials, in some scenarios with tight boundary conditions, only a local approach can be attempted for the analysis. This local approach to access the underlying features, such as circuits, solder bumps, and electrical traces will typically use conventional Laser Chemical Etching (LCE) platforms. The focus of this analysis will be to investigate and conjoin previously published techniques to this local preparation by using a combination of laser sources. A Continuous Wave (CW) and Pulse laser will be used at various processing stages to de-process IC packaging materials silicon and mold compound encapsulation.

Laser Chemical Etching Trench Refinements for Backside Debug Journey to the Circuit Layer

2020 ◽  
Author(s):  
Matthew M. Mulholland ◽  
Shida Tan ◽  
Muhammad Usman Raza ◽  
Matthew Levesque ◽  
Jordan Furlong ◽  
...  
Keyword(s):  
Pulse Laser ◽  
Chemical Etching ◽  
Focused Ion Beam ◽  
Continuous Wave ◽  
Ion Beam ◽  
Laser System ◽  
Laser Etching ◽  
Laser Patterning ◽  
Silicon Thickness ◽  
532 Nm

Abstract The journey to the circuit layer will be described by first discussing baseline processes of laser assisted chemical etching (LACE) steps before the focused ion beam (FIB) workflow. These LACE processes take advantage of a dual 532 nm continuous wave (CW) and pulse laser system, however limitations and overhead that is transferred over to the FIB operator will be demonstrated. Experiments show an additional third 355 nm ultraviolet (UV) pulse laser process introduction into the workflow can further reduce the remaining silicon thickness (RST) relieving FIB overhead. In addition, complex pulse laser patterning techniques will show a refinement to nonuniform produced silicon. Finally, other pulse laser patterning techniques such as polygon etch capability will allow laser etching around and in-between features to enhance circuit layer accessibility for debug operations.

Pulse Laser Ablation Techniques for IC Package Substrate Modifications and Validation

2016 ◽  
Author(s):  
Matthew M. Mulholland ◽  
Ahmed A. Helmy ◽  
Anthony V. Dao
Keyword(s):  
Integrated Circuits ◽  
Failure Analysis ◽  
Pulse Laser ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Back Side ◽  
Front Side ◽  
Local Approach ◽  
Ic Package ◽  
Level Analysis

Abstract Post silicon validation techniques specifically Focused Ion Beam (FIB) circuit editing and Failure Analysis (FA) require sample preparation on Integrated Circuits (IC). Although these preparation techniques are typically done globally across the encapsulated and silicon packaging materials, in some scenarios with tight mechanical or thermal boundary conditions, only a local approach can be attempted for the analysis. This local approach to access the underlying features, such as circuits, solder bumps, and electrical traces can be divided into two modification approaches. The back side approach is typically done for die level analysis by de-processing through encapsulated mold compound and silicon gaining access to the silicon transistor level. On the other hand, the front side approach is typically used for package level analysis by de-processing the ball grid array (BGA) and package substrate layers. Both of these local de-processing approaches can be done by using the conventional Laser Chemical Etching (LCE) platforms. The focus of this paper will be to investigate a front side modification approach to provide substrate material removal solutions. Process details and techniques will be discussed to gain access to metal signals for further failure analysis and debug. A pulse laser will be used at various processing stages to de-process IC package substrate materials.

Preparation of Wafer Level Packaged Integrated Circuits Using Pulsed Laser Assisted Chemical Etching

2012 ◽  
Author(s):  
Robert Chivas ◽  
Niru Dandekar ◽  
Scott Silverman ◽  
Roddy Cruz ◽  
Michael DiBattista
Keyword(s):  
Integrated Circuits ◽  
Chemical Etching ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Pulsed Laser ◽  
Surface Preparation ◽  
Wafer Level ◽  
Dimensional Control ◽  
Dry Process ◽  
Ultra High Purity

Abstract Pulsed Laser Assisted Chemical Etching (PLACE) is an advanced method of surface preparation that etches backside silicon to ultra-thin remaining layer thickness for Focused Ion Beam (FIB) circuit edit and failure analysis of Wafer Level Packages (WLP). PLACE can achieve ultra-high purity and fine dimensional control since it is a dry process relying on pyrolytic vapor phase reactions initiated, and constrained, by a pulsed laser.

Fluorocarbon Precursor for High Aspect Ratio via Milling in Focused Ion Beam Modification of Integrated Circuits

2004 ◽  
Author(s):  
Valery Ray
Keyword(s):  
Side Effects ◽  
Aspect Ratio ◽  
Integrated Circuits ◽  
High Aspect Ratio ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Enabling Technology ◽  
Si Substrate ◽  
Ion Beam Modification ◽  
The Past

Abstract Gas Assisted Etching (GAE) is the enabling technology for High Aspect Ratio (HAR) circuit access via milling in Focused Ion Beam (FIB) circuit modification. Metal interconnect layers of microelectronic Integrated Circuits (ICs) are separated by Inter-Layer Dielectric (ILD) materials, therefore HAR vias are typically milled in dielectrics. Most of the etching precursor gases presently available for GAE of dielectrics on commercial FIB systems, such as XeF2, Cl2, etc., are also effective etch enhancers for either Si, or/and some of the metals used in ICs. Therefore use of these precursors for via milling in dielectrics may lead to unwanted side effects, especially in a backside circuit edit approach. Making contacts to the polysilicon lines with traditional GAE precursors could also be difficult, if not impossible. Some of these precursors have a tendency to produce isotropic vias, especially in Si. It has been proposed in the past to use fluorocarbon gases as precursors for the FIB milling of dielectrics. Preliminary experimental evaluation of Trifluoroacetic (Perfluoroacetic) Acid (TFA, CF3COOH) as a possible etching precursor for the HAR via milling in the application to FIB modification of ICs demonstrated that highly enhanced anisotropic milling of SiO2 in HAR vias is possible. A via with 9:1 aspect ratio was milled with accurate endpoint on Si and without apparent damage to the underlying Si substrate.

Precision TEM Specimen Preparation for Integrated Circuits using Dual-Beam FIB Lift-Out Technique

2000 ◽  
Vol 6 (S2) ◽  
pp. 516-517
Author(s):  
Youren Xu ◽  
Chris Schwappach ◽  
Ron Cervantes
Keyword(s):  
Integrated Circuits ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Specimen Preparation ◽  
Single Beam ◽  
Dual Beam ◽  
Technological Advances ◽  
Endpoint Control ◽  
Practical Standpoint ◽  
Beam Damage

Focused ion beam lift-out technique has become increasingly attractive to the TEM community due to its unique advantage of no mechanical grinding/polishing involved in the process [1-3]. The technique essentially consists of two parts: preparation of membrane using focused ion beam (FIB) and transfer of the membrane (lift-out) to a grid. Up to date, this technique has only been demonstrated on single beam FIB systems. From a practical standpoint, overall sample quality (thickness) and lack of end-point precision are two major issues associated with the conventional single beam FIB technique. These issues are primarily related to ion beam damage and endpoint control encountered during the final stages of specimen thinning. As a result, the widespread use of FIB lift-out technique for high precision TEM specimen preparation has been limited. Recent technological advances have made it possible to combine both an electron beam column and an ion beam column into an integrated dual beam-focused ion beam (DB-FIB) system.

scholarly journals Understanding the Interdependence of Penetration Depth and Deformation on Nanoindentation of Nanoporous Silver

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1346
Author(s):  
Yannick Champion ◽  
Mathilde Laurent-Brocq ◽  
Pierre Lhuissier ◽  
Frédéric Charlot ◽  
Alberto Moreira Jorge Junior ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Chemical Etching ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Density Variation ◽  
Selective Chemical ◽  
Indent Depth ◽  
Selective Chemical Etching ◽  
Scanning Electron

A silver-based nanoporous material was produced by dealloying (selective chemical etching) of an Ag38.75Cu38.75Si22.5 crystalline alloy. Composed of connected ligaments, this material was imaged using a scanning electron microscope (SEM) and focused ion-beam (FIB) scanning electron microscope tomography. Its mechanical behavior was evaluated using nanoindentation and found to be heterogeneous, with density variation over a length scale of a few tens of nanometers, similar to the indent size. This technique proved relevant to the investigation of a material’s mechanical strength, as well as to how its behavior related to the material’s microstructure. The hardness is recorded as a function of the indent depth and a phenomenological description based on strain gradient and densification kinetic was proposed to describe the resultant depth dependence.

Focused Ion Beam Metrology

1995 ◽  
Vol 396 ◽  
Author(s):  
A. Wagner ◽  
P. Blauner ◽  
P. Longo ◽  
S. Cohen
Keyword(s):  
Integrated Circuits ◽  
Cross Sections ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Dimensional Change ◽  
Critical Dimension ◽  
Ion Beams ◽  
Near Surface ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes

AbstractFocused Ion Beams offer a new method of measuring the size of polymer resist features on integrated circuits. The short penetration range of an ion relative to an electron is shown to offer fundamental advantages for critical dimension (CD) metrology. By confining the polymer damage to the very near surface, ion beams can induce less dimensional change than scanning electron microscopes during the measurement process. This can result in improved CD measurement precision. The erosion rate of polymers to various ion species is also presented, and we show that erosion is non-linear with ion dose. The use of FIB for forming resist cross sections is also demonstrated. An H20 gas assisted etching process for polymers has been developed, and is shown to significantly improve the quality of resist cross sections.

Creation of 3D Patterns in Si by Focused Ga-Ion Beam and Anisotropic Wet Chemical Etching

1992 ◽  
Vol 279 ◽  
Author(s):  
Wei Chen ◽  
P. Chen ◽  
A. Madhukar ◽  
R. Viswanathan ◽  
J. So
Keyword(s):  
Chemical Etching ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Free Standing ◽  
Scale Thickness ◽  
Ion Beam Implantation ◽  
Etch Stop ◽  
Wet Chemical ◽  
Etching Behavior ◽  
Wet Chemical Etching

ABSTRACTWe report the realization of free standing 3D structures as tall as ∼ 7μm with nano-scale thickness in Si using the technique of Ga focused ion beam implantation and sputtering followed by wet chemical etching. Some of the previously investigated subjects such as anisotropie etching behavior of crystalline Si and etch stop effect of Ga+implanted Si etched in certain anisotropie chemical etchants have been further explored with the emphasis on exploiting them in realizing free standing structures. The design and fabrication considerations in achieving such free standing structures are discussed and some typical structures fabricated by this technique are shown.

Direct Imaging of Device Characteristics In a Focused ion Beam System

1998 ◽  
Vol 4 (S2) ◽  
pp. 652-653 ◽  
Author(s):  
A. N. Campbell ◽  
J. M. Soden
Keyword(s):  
Integrated Circuits ◽  
Failure Analysis ◽  
Cross Sections ◽  
Material Removal ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Yield Enhancement ◽  
The Past ◽  
Design Changes ◽  
Design Debugging

A great deal can be learned about integrated circuits (ICs) and microelectronic structures simply by imaging them in a focused ion beam (FIB) system. FIB systems have evolved during the past decade from something of a curiosity to absolutely essential tools for microelectronics design verification and failure analysis. FIB system capabilities include localized material removal, localized deposition of conductors and insulators, and imaging. A major commercial driver for FIB systems is their usefulness in the design debugging cycle by (1) rewiring ICs quickly to test design changes and (2) making connection to deep conductors to facilitate electrical probing of complex ICs. FIB milling is also used for making precision cross sections and for TEM sample preparation of microelectronic structures for failure analysis and yield enhancement applications.

TEM Sample Preparation Using A Focused Ion Beam and A Probe Manipulator

1996 ◽  
Author(s):  
L.R. Herlinger ◽  
S. Chevacharoenkul ◽  
D.C. Erwin
Keyword(s):  
Electron Microscope ◽  
Integrated Circuits ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Specific Area ◽  
Sem Analysis ◽  
Imaging Analysis ◽  
Mechanical Grinding ◽  
Transmission Electron ◽  
Multiple Samples

Abstract Cross-sectioning is a necessary technique for the failure analysis of integrated circuits. Historically, the majority of samples have been prepared for scanning electron microscope (SEM) analysis. Today's smaller geometry devices, however, increasingly require the improved spatial resolution afforded by the transmission electron microscope (TEM), both in imaging analysis and in elemental analysis. Specific-area cross-section TEM (SAXTEM) analysis allows the failure analyst to identify defects that may go undiscovered in the SEM. A procedure is described for a timely preparation of SAXTEM samples using a focused ion beam (FIB) instrument and a manipulator probe. This procedure extends the state-of-the-art in several key respects: A) no mechanical grinding is necessary, B) samples as large as the FIB chamber can be accommodated, e.g., whole wafers, C) multiple samples can be prepared from one die, D) the procedure is faster and more repeatable than previously reported procedures.

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