Flip-Chip and Backside Techniques
Abstract not provided.
Publications
Flip-Chip and Backside Techniques
Conference Proceedings from the International Symposium for Testing and Failure Analysis
Abstract not provided.
Flip-Chip and Backside Techniques
Abstract not provided.
Flip-chip and backside techniques
State-of-the-art techniques for failure localization and design modification through bulk silicon are essential for multi-level metallization and new, flip chip packaging methods. The tutorial reviews the transmission of light through silicon, sample preparation, and backside defect localization techniques that are both currently available and under development. The techniques covered include emission microscopy, scanning laser microscope based techniques (electrooptic techniques, LIVA and its derivatives), and other non-IR based tools (FIB, e-beam techniques, etc.).
Flip-Chip and Backside Techniques Seminar ISTFA '09
Abstract not provided.
LDRD final report on Bloch Oscillations in two-dimensional nanostructure arrays for high frequency applications
We have investigated the physics of Bloch oscillations (BO) of electrons, engineered in high mobility quantum wells patterned into lateral periodic arrays of nanostructures, i.e. two-dimensional (2D) quantum dot superlattices (QDSLs). A BO occurs when an electron moves out of the Brillouin zone (BZ) in response to a DC electric field, passing back into the BZ on the opposite side. This results in quantum oscillations of the electron--i.e., a high frequency AC current in response to a DC voltage. Thus, engineering a BO will yield continuously electrically tunable high-frequency sources (and detectors) for sensor applications, and be a physics tour-de-force. More than a decade ago, Bloch oscillation (BO) was observed in a quantum well superlattice (QWSL) in short-pulse optical experiments. However, its potential as electrically biased high frequency source and detector so far has not been realized. This is partially due to fast damping of BO in QWSLs. In this project, we have investigated the possibility of improving the stability of BO by fabricating lateral superlattices of periodic coupled nanostructures, such as metal grid, quantum (anti)dots arrays, in high quality GaAs/Al{sub x}Ga{sub 1-x}As heterostructures. In these nanostructures, the lateral quantum confinement has been shown theoretically to suppress the optical-phonon scattering, believed to be the main mechanism for fast damping of BO in QWSLs. Over the last three years, we have made great progress toward demonstrating Bloch oscillations in QDSLs. In the first two years of this project, we studied the negative differential conductance and the Bloch radiation induced edge-magnetoplasmon resonance. Recently, in collaboration with Prof. Kono's group at Rice University, we investigated the time-domain THz magneto-spectroscopy measurements in QDSLs and two-dimensional electron systems. A surprising DC electrical field induced THz phase flip was observed. More measurements are planned to investigate this phenomenon. In addition to their potential device applications, periodic arrays of nanostructures have also exhibited interesting quantum phenomena, such as a possible transition from a quantum Hall ferromagnetic state to a quantum Hall spin glass state. It is our belief that this project has generated and will continue to make important impacts in basic science as well as in novel solid-state, high frequency electronic device applications.
Improving Epitaxial Growth for LEDs (invited)
Abstract not provided.
Flip-Chip and Backside Techniques Seminar ISTFA'07
Abstract not provided.
LDRD final report on Si nanocrystal as device prototype for spintronics applications
The silicon microelectronics industry is the technological driver of modern society. The whole industry is built upon one major invention--the solid-state transistor. It has become clear that the conventional transistor technology is approaching its limitations. Recent years have seen the advent of magnetoelectronics and spintronics with combined magnetism and solid state electronics via spin-dependent transport process. In these novel devices, both charge and spin degree freedoms can be manipulated by external means. This leads to novel electronic functionalities that will greatly enhance the speed of information processing and memory storage density. The challenge lying ahead is to understand the new device physics, and control magnetic phenomena at nanometer length scales and in reduced dimensions. To meet this goal, we proposed the silicon nanocrystal system, because: (1) It is compatible with existing silicon fabrication technologies; (2) It has shown strong quantum confinement effects, which can modify the electric and optical properties through directly modifying the band structure; and (3) the spin-orbital coupling in silicon is very small, and for isotopic pure {sup 28}Si, the nuclear spin is zero. These will help to reduce the spin-decoherence channels. In the past fiscal year, we have studied the growth mechanism of silicon-nanocrystals embedded in silicon dioxide, their photoluminescence properties, and the Si-nanocrystal's magnetic properties in the presence of Mn-ion doping. Our results may demonstrate the first evidence of possible ferromagnetic orders in Mn-ion implanted silicon nanocrystals, which can lead to ultra-fast information process and ultra-dense magnetic memory applications.
LDRD final report backside localization of open and shorted IC interconnections LDRD Project (FY98 and FY 99)
Two new failure analysis techniques have been developed for backside and front side localization of open and shorted interconnections on ICs. These scanning optical microscopy techniques take advantage of the interactions between IC defects and localized heating using a focused infrared laser ({lambda} = 1,340 nm). Images are produced by monitoring the voltage changes across a constant current supply used to power the IC as the laser beam is scanned across the sample. The methods utilize the Seebeck Effect to localize open interconnections and Thermally-Induced Voltage Alteration (TIVA) to detect shorts. Initial investigations demonstrated the feasibility of TIVA and Seebeck Effect Imaging (SEI). Subsequent improvements have greatly increased the sensitivity of the TIVA/SEI system, reducing the acquisition times by more than 20X and localizing previously unobserved defects. The interaction physics describing the signal generation process and several examples demonstrating the localization of opens and shorts are described. Operational guidelines and limitations are also discussed. The system improvements, non-linear response of IC defects to heating, modeling of laser heating and examples using the improved system for failure analysis are presented.
10 Results