Author's Latest Posts


Metal-Oxide-Metal Capacitor Simulation And Modeling By Virtual Fabrication


Metal-Oxide-Metal (MOM) capacitors are passive radio frequency (RF) capacitive devices that are a common component in semiconductor logic chips [1]. A SPICE model of a MOM capacitor is typically used by designers during the design and performance evaluation of logic chip RF circuitry. Traditionally, it may take at least 3 months from the completion of the design layout, wafer fabrication, final... » read more

Improving Line Edge Roughness Using Virtual Fabrication


Line edge roughness (LER) is a variation in the width of a lithographic pattern along one edge of a structure inside a chip. Line edge roughness can be a critical variation source and defect mechanism in advanced logic and memory devices and can lead to poor device performance or even device failure. [1~3]. Deposition-etch cycling is an effective technique to reduce line edge roughness. In this... » read more

The Impact Of Channel Hole Profiles On Advanced 3D NAND Structures


In a two-tier 3D NAND structure, the upper and lower channel hole profile can be different, and this combination of different profiles leads to different top-down visible areas. The visible area is the key metric to determine whether the bottom SONO layer can be punched through and ensure that the bit cells connect to the common source line. Performing channel hole profile splits on a silicon w... » read more

Insights Into Advanced DRAM Capacitor Patterning: Process Window Evaluation Using Virtual Fabrication


With continuous device scaling, process windows have become narrower and narrower due to smaller feature sizes and greater process step variability [1]. A key task during the R&D stage of semiconductor development is to choose a good integration scheme with a relatively large process window. When wafer test data is limited, evaluating the process window for different integration schemes can... » read more

Accelerating Semiconductor Process Development Using Virtual Design Of Experiments


Design of Experiments (DOE) are a powerful concept in semiconductor engineering research and development. DOEs are sets of experiments used to explore the sensitivity of experimental variables and their effect on final device performance. A well-designed DOE can help an engineer achieve a targeted semiconductor device performance using a limited number of experimental wafer runs. However, in se... » read more

Using A Virtual DOE To Predict Process Windows And Device Performance Of Advanced FinFET Technology


By Qingpeng Wang, Yu De Chen, Cheng Li, Rui Bao, Jacky Huang, and Joseph Ervin Introduction With continuing finFET device process scaling, micro loading control becomes increasingly important due to its significant impact on yield and device performance [1-2]. Micro-loading occurs when the local etch rate on a wafer is dependent upon existing feature sizes and local pattern density. Uninten... » read more

Micro Loading And Its Impact On Device Performance


In a DRAM structure, the charging and discharging process of capacitor-based memory cells is directly controlled by the transistor [1]. With transistor sizes approaching the lower limits of physical achievability, manufacturing variability and micro loading effects are becoming increasingly critical DRAM performance (and yield) limiters. The transistor’s AA (active area) dimension and profile... » read more

Identifying And Preventing Process Failures At 7nm


Device yield is highly dependent upon proper process targeting and variation control of fabrication steps, particularly at advanced nodes with smaller feature sizes. Traditionally, cross-correlation and analysis of thousands of test data points have been required to identify and prevent process failures. This is very costly in terms of both time and money. Fortunately, semiconductor virtual fab... » read more