Translating Yield Learning Into Manufacturable Designs

2006 ◽  
Author(s):  
Vijay Chowdhury ◽  
Irfan Rahim ◽  
Ada Yu ◽  
Girish Venkitachalam
Keyword(s):  
Failure Modes ◽  
Analog Circuit ◽  
Yield Loss ◽  
Process Variations ◽  
Design Sensitivity ◽  
Design For Manufacturability ◽  
Design Rules ◽  
Circuit Layout ◽  
Manufacturing Defects ◽  
Yield Learning

Abstract Improving semiconductor yield is a multi-dimensional process that must include design, fabrication, and test aspects. Incorporating design-for-manufacturability (DFM) concepts needs to include prior and ongoing learning and experience on what worked and what did not. As feature sizes shrink beyond 130nm, it is possible to identify another class of failures that is more systematic and related not to manufacturing defects but to DFM marginalities related to layout. In this article, it is shown that DFM can also help reduce design sensitivity to process variations. Examples of these failure modes and the lessons learnt are listed: relaxed design rules for repeated patterns, relaxing design rules to reduce yield loss, and special considerations for analog circuit layout.

On Debugging Intermittent Chain Hold-time Failures Caused by Process Variations for FinFET Technology

2020 ◽  
Author(s):  
Huaxing Tang ◽  
Allen Yang ◽  
Zhanjun Shu ◽  
Eden Cai ◽  
Shizhong Chen ◽  
...  
Keyword(s):  
Standard Method ◽  
Hold Time ◽  
Process Variations ◽  
Manufacturing Defects ◽  
Test Compression ◽  
Yield Learning ◽  
Scan Chains

Abstract Scan-based test has been the industrial standard method for screening manufacturing defects. Scan chains are vulnerable to most manufacturing defects and process variations. Therefore, chain failures diagnosis is critical for successful yield learning. However, traditional chain diagnosis requires failing masking patterns to identify faulty chains and their fault types for designs with test compression. In other words, it cannot diagnose the chain failures which don't fail the masking chain patterns. Unfortunately, advanced FinFET technologies with more manufacturing challenges and higher process variations may result in more subtle chain timing failures which can't be detected by chain masking patterns. In this work, we present a new debugging methodology, which combines chain diagnosis and tester-based test to effectively diagnose such intermittent chain failures. The proposed methodology is validated on silicon data for one modern large SOC design and successfully identified all scan cells with hold-time issues, which were validated by STA with corrected models. The subsequent mask fixes for these identified hold-time violations resolved this yield issue and dramatically improve the yield.

Sub-20nm Device Voltage-Sensitive SRAM Characterization and Failure Analysis

2018 ◽  
Author(s):  
Seng Nguon Ting ◽  
Hsien-Ching Lo ◽  
Donald Nedeau ◽  
Aaron Sinnott ◽  
Felix Beaudoin
Keyword(s):  
Failure Analysis ◽  
High Performance ◽  
Yield Loss ◽  
Technology Development ◽  
High Density ◽  
High K ◽  
Yield Learning ◽  
Oxide Deposition ◽  
Edge Profile ◽  
High K Dielectric

Abstract With rapid scaling of semiconductor devices, new and more complicated challenges emerge as technology development progresses. In SRAM yield learning vehicles, it is becoming increasingly difficult to differentiate the voltage-sensitive SRAM yield loss from the expected hard bit-cells failures. It can only be accomplished by extensively leveraging yield, layout analysis and fault localization in sub-micron devices. In this paper, we describe the successful debugging of the yield gap observed between the High Density and the High Performance bit-cells. The SRAM yield loss is observed to be strongly modulated by different active sizing between two pull up (PU) bit-cells. Failure analysis focused at the weak point vicinity successfully identified abnormal poly edge profile with systematic High k Dielectric shorts. Tight active space on High Density cells led to limitation of complete trench gap-fill creating void filled with gate material. Thanks to this knowledge, the process was optimized with “Skip Active Atomic Level Oxide Deposition” step improving trench gap-fill margin.

Design Rules and Failure Modes of DMFC Stack Development

2019 ◽  
Vol 26 (1) ◽  
pp. 287-294 ◽  
Author(s):  
Youngseung Na ◽  
Seong Kee Yoon ◽  
Jungkurn Park ◽  
Jun Won Suh ◽  
Inseob Song ◽  
...  
Keyword(s):  
Failure Modes ◽  
Design Rules

scholarly journals A Factory Analysis on the Proportion of Defects Reduction in The Animal Feed Pellet Production Process using Design of Experiment Analysis

2019 ◽  
Vol 3 (2) ◽  
pp. 26-33
Author(s):  
Keyword(s):  
Production Process ◽  
Failure Modes ◽  
Animal Feed ◽  
Fractional Factorial ◽  
Pareto Chart ◽  
Manufacturing Defects ◽  
Root Cause ◽  
Pellet Production ◽  
Feed Pellet

The aim of this research is to reduce a number of defects during a feed pellet production process to improve customer satisfaction. A factory case study produces the feed pellets for several species such as food for pigs, chickens, and ducks. Production data from January to June 2017 manufacturing found that the manufacturing defects rate were about 3.32%. The data showed that the overall defects originated from different problems; 1) cracked or broken food; 2) high humidity; 3) distorted of product color; and 4) an ingredient error, respectively. Statistical methods, design analysis, and cause analysis techniques e.g. the Ishikawa diagram, Pareto chart, and FMEA (Failure Mode and Effects Analysis) were applied to help the factory to identify the main root cause of the defects and the potential failure modes of the factory case study. Due to an increasing number of complaints, this study only concentrated on the duck feed pellet production process. The study was divided into two parts: finding the root cause of the defects, which are the most critical factors for further analysis, and applying an experimental statistical design to decrease the number of defects during the duck pellet production process. The problem with cracked or broken pellets (dust) was found as the main factor affecting the production defects. Results showed that the main factors contributing to the amount of dusk in the duck feed productions came from three factors as follow: the thickness of die, distance between compression rollers and die, and time and temperature of mill machine needed during compressing the duck feed pellet production. Both the fractional factorial experimental design, 2k and 3k, were used to evaluate the influence of each factor on the duck feed production defects. The results by using the factorial 2K experimental show that the most important variable in duck pellets production were thickness of the die, distance between compression rollers and die, and temperature of mill machine needed during compressing the duck feed pellet production while time was not an interaction effect in this problem. The 3k factorial design was used to determine the interaction effects for the duck pellets production process. The experiment was ran and tested for 3 months. The final outcomes showed a significant reduction of defects from 2.51% to 1.09% (P<0.01). The results indicated that thickness -20 mm. of the die, 0.05 mm of distance between compression rollers and die, and 95 degree Celsius of temperature of mill machine needed during compressing the duck feed pellet production would be the most appropriate set of pelleting machine for the duck production process case study.

Mechanical Characterization of Metal Additively Manufactured Contact Aided Cellular Compliant Mechanisms

2021 ◽  
Author(s):  
Jivtesh B. Khurana ◽  
Mary Frecker
Keyword(s):  
Failure Modes ◽  
Mechanical Response ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
Mechanical Test ◽  
Single Cells ◽  
Compression Testing ◽  
Balance Performance ◽  
Manufacturing Defects ◽  
Lattice Design

Abstract Additive manufacturing allows for the creation of complex geometries that can be optimized for performance. However, understanding the effect of the manufacturing process on part performance is essential to balance performance with manufacturability. In this work, a cellular contact aided compliant mechanism previously designed by the authors is manufactured using laser powder bed fusion. Failure modes for C3M lattice design are highlighted and recommendations for manufacturability are obtained. The mechanical response of C3Ms is characterized through compression testing of lattice and single cells. Compression testing is used to understand the mode of energy absorption of C3M lattices and compare with mechanical simulations. Lattices with large wall thickness and largest cell size are found to absorb the most strain energy. The increase in stiffness of the C3M lattice is found to depend on the thickness of the cell walls and size of the contact gap. The failure modes based on manufacturing and mechanical test data are synthesized to generate design rules for selecting C3M geometry to minimize manufacturing defects and maximize performance.

Applicability of Design Rules for Openings in Shells, ASME B&PV Code, Section VIII, Division 2 - A Case Study

2021 ◽  
Author(s):  
Gurumurthy Kagita ◽  
Krishnakant V. Pudipeddi ◽  
Subramanyam V. R. Sripada
Keyword(s):  
Stress Analysis ◽  
Failure Modes ◽  
Element Analysis ◽  
Design Rules ◽  
Area Method ◽  
Replacement Method ◽  
Local Stresses ◽  
Pressure Area ◽  
Section Viii ◽  
Division 2

Abstract The Pressure-Area method is recently introduced in the ASME Boiler and Pressure Vessel (B&PV) Code, Section VIII, Division 2 to reduce the excessive conservatism of the traditional area-replacement method. The Pressure-Area method is based on ensuring that the resistive internal force provided by the material is greater than or equal to the reactive load from the applied internal pressure. A comparative study is undertaken to study the applicability of design rules for certain nozzles in shells using finite element analysis (FEA). From the results of linear elastic FEA, it is found that in some cases the local stresses at the nozzle to shell junctions exceed the allowable stress limits even though the code requirements of Pressure-Area method are met. It is also found that there is reduction in local stresses when the requirement of nozzle to shell thickness ratio is maintained as per EN 13445 Part 3. The study also suggests that the reinforcement of nozzles satisfy the requirements of elastic-plastic stress analysis procedures even though it fails to satisfy the requirements of elastic stress analysis procedures. However, the reinforcement should be chosen judiciously to reduce the local stresses at the nozzle to shell junction and to satisfy other governing failure modes such as fatigue.

Assembly FMEA: A Simplified Method for Identifying Assembly Errors

2003 ◽  
Author(s):  
Steven Kmenta ◽  
Brent Cheldelin ◽  
Kosuke Ishii
Keyword(s):  
Artificial Intelligence ◽  
Failure Modes ◽  
Electronic Circuits ◽  
Manual Assembly ◽  
Manufacturing Defects ◽  
Novel Technique ◽  
Analysis Process ◽  
Simplified Method ◽  
Process Failure ◽  
Assembly Defect

Manual assembly errors are a significant source of manufacturing defects. Therefore, an efficient method is needed to identify and alleviate potential assembly defects. Process Failure Modes and Effects Analysis (Process FMEA) is one technique used to anticipate, evaluate, and resolve potential manufacturing and assembly issues. However, performing FMEA is widely considered to be tedious and time-consuming, and not always worth the effort. In response, many researchers have attempted to automate FMEA using Artificial Intelligence (AI) to make it less arduous. Unfortunately, automated techniques are limited to systems with predictable behaviors (e.g., electronic circuits) and are rarely used on unpredictable processes such as manual assembly. “Assembly FMEA” is a novel technique developed specifically to identify manual assembly errors. Assembly defect levels are related to assembly complexity, which can be estimated using “Design for Assembly” (DFA) time penalties. Hence, Assembly FMEA uses a series of DFA-related questions to elicit potential assembly defects. The questions help to focus, standardize, and expedite the FMEA process. Assembly FMEA quickly identifies a large number of assembly errors with significantly less effort than conventional FMEA. This paper describes the Assembly FMEA procedure and illustrates its use on a conceptual design and on an existing product.

ANALYTICAL AND FINITE ELEMENT MODELING AND SIMULATION OF BUCKLING AND POSTBUCKLING OF DELAMINATED ORTHOTROPIC PLATES

2011 ◽  
Vol 02 (01) ◽  
pp. 97-104 ◽  
Author(s):  
LALITHA CHATTOPADHYAY ◽  
S. SRIDHARA MURTHY
Keyword(s):  
Finite Element ◽  
Strain Energy ◽  
Failure Modes ◽  
Integral Transform ◽  
Laminated Composite ◽  
Strain Energy Release ◽  
Orthotropic Plates ◽  
Manufacturing Defects ◽  
Laminated Composite Materials ◽  
Plane Compression

Delamination is one of the most common failure modes of laminated composite materials, and can be caused by manufacturing defects or impact loading. Under compression, a delaminated composite plate may buckle and tend to enlarge the delaminated area, which can lead to loss of global structural stability. This paper presents the elastic buckling and postbuckling analysis of an axially loaded beam-plate with an across-the-width delamination, located at a given depth below the upper surface of the plate. The analysis is done by considering a layered orthotropic plate containing through-width delamination, subjected to in-plane compression. The problem is analyzed by two approaches: (i) A simple analytical model for determining strain energy release rate is obtained using integral transform approach; (ii) A finite element representation of the problem is modeled and analyzed using MSC/NASTRAN and the buckling load is calculated.

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