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

Virtual Exploration Of Novel Vertical DRAM Architectures


In this article, we demonstrate a pathfinding technique for a novel Vertical DRAM technology. First, we identify important process parameters (defined by current semiconductor production equipment capabilities) that strongly impact yield. By using a virtual model, we then perform experimental optimization of the Vertical DRAM device across specific target ranges, to help predict and improve the... » read more

Understanding CFETs, A Next Generation Transistor Architecture


Computing power has experienced exponential growth over the last 70 years. This has largely been achieved through transistor scaling. Due to a continuous reduction in the size of transistors, engineers have been able to pack more and more of them onto a single chip [1]. This has led to faster, more powerful, and more energy-efficient devices. Improvements in fabrication processes and materials,... » read more

Techniques To Identify And Correct Asymmetric Wafer Map Defects Caused By Design And Process Errors


Asymmetries in wafer map defects are usually treated as random production hardware defects. For example, asymmetric wafer defects can be caused by particles inadvertently deposited on a wafer during any number of process steps. In this article, I want to share a different mechanism that can cause wafer defects. Namely, that these defects can be structural defects that are caused by a biased dep... » read more

Developing ReRAM As Next Generation On-Chip Memory For Machine Learning, Image Processing And Other Advanced CPU Applications


In modern CPU device operation, 80% to 90% of energy consumption and timing delays are caused by the movement of data between the CPU and off-chip memory. To alleviate this performance concern, designers are adding additional on-chip memory to their CPUs. Traditionally, SRAM has been the most widely used on-chip CPU memory type. Unfortunately, SRAM is currently limited to a size of hundreds of ... » read more

Improving Semiconductor Yield Using Large Area Analysis


Design rule checking (DRC) is a technique used during chip design to ensure that a device can successfully be manufactured at high yield. Design rules are established based on the limits and variability of equipment and process technologies in use. DRC checking ensures that a design meets manufacturing requirements and will not result in a chip failure or DRC “violation.” Common DRC rules i... » 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

Improving Gate All Around Transistor Performance Using Virtual Process Window Exploration


As transistor sizes shrink, short channel effects make it more difficult for transistor gates to turn a transistor ON and OFF [1]. One method to overcome this problem is to move away from planar transistor architectures toward 3D devices. Gate-all-around (GAA) architectures are an example of this type of 3D device [2]. In a GAA transistor, the gate oxide surrounds the channel in all directions.... » read more

Improving DRAM Device Performance Through Saddle Fin Process Optimization


As DRAM technology nodes have scaled down, access transistor issues have been highlighted due to weak gate controllability. Saddle Fins with Buried Channel Array Transistors (BCAT) have subsequently been introduced to increase channel length, prevent short channel effects, and increase data retention times [1]. However, at technology nodes beyond 20nm, securing sufficient device performance (su... » read more

A Deposition And Etch Technique To Lower Resistance Of Semiconductor Metal Lines


Copper's resistivity depends on its crystal structure, void volume, grain boundaries and material interface mismatch, which becomes more significant at smaller scales. The formation of copper (Cu) wires is traditionally done by etching a trench pattern in low-k silicon dioxide using a trench etch process, and subsequently filling the trench with Cu via a damascene flow. Unfortunately, this meth... » read more

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