Analysis Approach on DMOS Transistor Vth Mismatch Due to Trapped Charges

2015 ◽  
Author(s):  
Hashim Ismail ◽  
Ang Chung Keow ◽  
Kenny Gan Chye Siong
Keyword(s):  
Failure Analysis ◽  
Threshold Voltage ◽  
Gate Oxide ◽  
Analysis Approach ◽  
Test Results ◽  
Root Cause ◽  
Switching Event ◽  
Output Transistor ◽  
Event Based ◽  
Trapped Charge

Abstract An output switching malfunction was reported on a bridge driver IC. The electrical verification testing revealed evidence of an earlier over current condition resulting from an abnormal voltage sense during a switching event. Based on these test results, we developed the hypothesis that a threshold voltage mismatch existed between the sense transistor and the output transistor. This paper describes the failure analysis approach we used to characterize the threshold voltage mismatch as well as our approach to determine the root cause, which was trapped charge on the gate oxide of the sense transistor.

A New Failure Analysis Flow of Gate Oxide Integrity Failure in Wafer Fabrication

2009 ◽  
Author(s):  
Hua Younan ◽  
Chu Susan ◽  
Gui Dong ◽  
Mo Zhiqiang ◽  
Xing Zhenxiang ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Gate Dielectric ◽  
Dielectric Breakdown ◽  
Defect Density ◽  
Gate Oxide ◽  
Oxide Thickness ◽  
Fault Isolation ◽  
Wafer Fabrication ◽  
Root Cause ◽  
Gate Oxide Integrity

Abstract As device feature size continues to shrink, the reducing gate oxide thickness puts more stringent requirements on gate dielectric quality in terms of defect density and contamination concentration. As a result, analyzing gate oxide integrity and dielectric breakdown failures during wafer fabrication becomes more difficult. Using a traditional FA flow and methods some defects were observed after electrical fault isolation using emission microscopic tools such as EMMI and TIVA. Even with some success with conventional FA the root cause was unclear. In this paper, we will propose an analysis flow for GOI failures to improve FA’s success rate. In this new proposed flow both a chemical method, Wright Etch, and SIMS analysis techniques are employed to identify root cause of the GOI failures after EFA fault isolation. In general, the shape of the defect might provide information as to the root cause of the GOI failure, whether related to PID or contamination. However, Wright Etch results are inadequate to answer the questions of whether the failure is caused by contamination or not. If there is a contaminate another technique is required to determine what the contaminant is and where it comes from. If the failure is confirmed to be due to contamination, SIMS is used to further determine the contamination source at the ppm-ppb level. In this paper, a real case of GOI failure will be discussed and presented. Using the new failure analysis flow, the root cause was identified to be iron contamination introduced from a worn out part made of stainless steel.

Voltage Regulator Output Shifts Due to Systematic Oxide Non-Uniformities: Failure Analysis, Layout and Process Solutions

2004 ◽  
Author(s):  
R. Jumpertz ◽  
D. Muigg ◽  
R. Oberhuber ◽  
W. Ploss ◽  
T. Chatterjee ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Process Analysis ◽  
Gate Oxide ◽  
High Volume ◽  
Oxide Thickness ◽  
Voltage Regulator ◽  
Analog Device ◽  
Root Cause ◽  
Significant Yield ◽  
Process Solutions

Abstract High volume productions of analog devices require usually more than one production facility. These facilities could be part of the company or in a foundry organization. A smart technology transfer is a key requirement to success. Nevertheless, small deviations of parametric key indices can lead to substantial differences in analog device performance. This paper describes an instructive case study to isolate the root cause of a parametric shift of a low drop output (LDO) voltage regulator. This shift caused a significant yield loss in one of the production facilities. The LDO shift was traced back to a current mirror mismatch. Physical failure analysis shows small differences in the gate oxide thickness which consequently vise versa led to threshold voltage mismatch. Further process analysis identified an unwanted topography in the silicon surface as the root cause of the non-uniform gate oxide growth.

Failure Analysis Methodology on Systematic Defect in N+ poly/NWELL Varactor in RF Analog_PLL due to Implanter Charging Issue

2012 ◽  
Author(s):  
Ang Ghim Boon ◽  
Chen Changqing ◽  
Ng Hui Peng ◽  
Neo Soh Ping ◽  
Magdeliza G ◽  
...  
Keyword(s):  
Problem Solving ◽  
Failure Analysis ◽  
Gate Oxide ◽  
Oxide Breakdown ◽  
Root Cause ◽  
Path Tracing ◽  
Analysis Methodology ◽  
Problem Solving Process ◽  
Access To Data ◽  
Analog Circuitry

Abstract In this paper, a zero yield case relating to a systematic defect in N+ poly/N-well varactor (voltage controlled capacitor) on the RF analog circuitry will be studied. The systematic problem solving process based on the application of a variety of FA techniques such as TIVA, AFP current Imaging and nano-probing, manual layout path tracing, FIB circuit edit, selective etching together with Fab investigation is used to understand the root cause as well as failure mechanism proposed. This process is particularly critical for a foundry company with restricted access to data on test condition setup to duplicate the exact failure as well as no layout tracing available at time of analysis. The systematic defect was due to gate oxide breakdown as a result of implanter charging. It serves as a good reference to other wafer Fabs encountering such an issue.

An Advanced Reliability Improvement and Failure Analysis Approach to Thermal Stress Issues in IC Packages

2009 ◽  
Author(s):  
Michael Hertl ◽  
Diane Weidmann ◽  
Alex Ngai
Keyword(s):  
Thermal Stress ◽  
Failure Analysis ◽  
Deformation Measurement ◽  
Stress Conditions ◽  
Analysis Approach ◽  
New Approach ◽  
Reliability Improvement

Abstract A new approach to reliability improvement and failure analysis on ICs is introduced, involving a specifically developed tool for Topography and Deformation Measurement (TDM) under thermal stress conditions. Applications are presented including delamination risk or bad solderability assessment on BGAs during JEDEC type reflow cycles.

Burn-in Failure Analysis of 0.5μm 1MB SRAM: Barrier Glue Layer Cracks and Tungsten Plug “Worm Holes”

1996 ◽  
Author(s):  
E. Widener ◽  
S. Tatti ◽  
P. Schani ◽  
S. Crown ◽  
B. Dunnigan ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Product Quality ◽  
Cmos Process ◽  
Designed Experiments ◽  
Root Cause ◽  
Poly Silicon ◽  
New Process ◽  
Supply Current ◽  
Electrical Analysis ◽  
Current Characteristics

Abstract A new 0.5 um 1 Megabit SRAM which employed a double metal, triple poly CMOS process with Tungsten plug metal to poly /silicon contacts was introduced. During burn-in of this product, high currents, apparently due to electrical overstress, were experienced. Electrical analysis showed abnormal supply current characteristics at high voltages. Failure analysis identified the sites of the high currents of the bum-in rejects and discovered cracks in the glue layer prior to Tungsten deposition as the root cause of the failure. The glue layer cracks allowed a reaction with the poly/silicon, causing opens at the bottom of contacts. These floating nodes caused high currents and often latch-up during burn-in. Designed experiments in the wafer fab identified an improved glue layer process, which has been implemented. The new process shows improvement in burn in performance as well as outgoing product quality.

A Study of Pad Contamination Defect and Removal

2008 ◽  
Author(s):  
K.A. Mohammad ◽  
L.J. Liu ◽  
S.F. Liew ◽  
S.F. Chong ◽  
D.G. Lee ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Gate Oxide ◽  
Action Plans ◽  
Preventive Action ◽  
Oxide Breakdown ◽  
Reliability Level ◽  
The Future ◽  
Dry Etch ◽  
Removal Technique

Abstract The paper focuses on the pad contamination defect removal technique. The defect is detected at the outgoing inspection step. The failure analysis results showed that the defect is Fluorine type contamination. The failure analysis indicated many source contributors mainly from Fluorine based processes. The focus is in the present work is in the rework method for the removal of this defect. The combination of wet and dry etch processing in the rework routine is utilized for the removal of the defect and preventive action plans for in-line were introduced and implemented to avoid this event in the future. The reliability of the wafer is verified using various tests including full map electrical, electrical sort, gate oxide breakdown (GOI) and wafer reliability level, passivation quick kill to ensure the integrity of the wafer after undergoing the rework routine. The wafer is monitored closely over a period of time to ensure it has no mushroom defect.

Precision Xe Plasma FIB Delayering for Physical Failure Analysis of Sub-20 nm Microprocessor Devices

2017 ◽  
Author(s):  
D. Zudhistira ◽  
V. Viswanathan ◽  
V. Narang ◽  
J.M. Chin ◽  
S. Sharang ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Dielectric Films ◽  
Planar Surface ◽  
Chemical Methods ◽  
Root Cause ◽  
Essential Step ◽  
Dielectric Layers ◽  
Wet Chemical ◽  
20 Nm ◽  
Low K

Abstract Deprocessing is an essential step in the physical failure analysis of ICs. Typically, this is accomplished by techniques such as wet chemical methods, RIE, and mechanical manual polishing. Manual polishing suffers from highly non-uniform delayering particularly for sub 20nm technologies due to aggressive back-end-of-line scaling and porous ultra low-k dielectric films. Recently gas assisted Xe plasma FIB has demonstrated uniform delayering of the metal and dielectric layers, achieving a planar surface of heterogeneous materials. In this paper, the successful application of this technique to delayer sub-20 nm microprocessor chips with real defects to root cause the failure is presented.

SEM-Based Nanoprobing on 40, 32 and 28 nm CMOS Devices Challenges for Semiconductor Failure Analysis

2013 ◽  
Author(s):  
Erik Paul ◽  
Holger Herzog ◽  
Sören Jansen ◽  
Christian Hobert ◽  
Eckhard Langer
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Failure Analysis ◽  
Case Studies ◽  
State Of The Art ◽  
Root Cause ◽  
Highly Efficient ◽  
Technology Nodes ◽  
Scanning Electron

Abstract This paper presents an effective device-level failure analysis (FA) method which uses a high-resolution low-kV Scanning Electron Microscope (SEM) in combination with an integrated state-of-the-art nanomanipulator to locate and characterize single defects in failing CMOS devices. The presented case studies utilize several FA-techniques in combination with SEM-based nanoprobing for nanometer node technologies and demonstrate how these methods are used to investigate the root cause of IC device failures. The methodology represents a highly-efficient physical failure analysis flow for 28nm and larger technology nodes.

Marginal RF Gain Investigation and Root Cause Determination

2013 ◽  
Author(s):  
Keith Harber ◽  
Steve Brockett
Keyword(s):  
Radio Frequency ◽  
Failure Analysis ◽  
Power Amplifier ◽  
Physical Analysis ◽  
Root Cause ◽  
S Parameter ◽  
Mode Of Operation ◽  
S Parameters

Abstract This paper outlines the failure analysis of a Radio Frequency only (RF-only) failure on a complex Multimode Multiband Power Amplifier (MMPA) module, where slightly lower gain was observed in one mode of operation. 2 port S-parameter information was collected and utilized to help localize the circuitry causing the issue. A slight DC electrical difference was observed, and simulation was utilized to confirm that difference was causing the observed S-parameters. Physical analysis uncovered a very visible cause for the RF-only failure.

Novel FIB Use for Failure Analysis of MEMS Gyroscopes

2016 ◽  
Author(s):  
Nathan Wang ◽  
Saunil Shah ◽  
Camille Garcia ◽  
Vicente Pasating ◽  
George Perreault
Keyword(s):  
Thin Films ◽  
Integrated Circuits ◽  
Failure Analysis ◽  
New Techniques ◽  
Unique Challenge ◽  
Root Cause ◽  
Large Size ◽  
Mems Gyroscopes

Abstract MEMS samples, with their relatively large size and weight, present a unique challenge to the failure analyst as they also included thin films and microstructures used in conventional integrated circuits. This paper describes how to accommodate the large MEMS structures without skimping on the microanalyses needed to get to the root cause. Investigations of tuning folk gyroscopes were used to demonstrate these new techniques.

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