Integrated Circuit Filler Cells for Faster e-Beam Defect Inspection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing e-beam inspection methods in the semiconductor industry face challenges such as low inspection sensitivity, low throughput, and long analysis cycle times due to their limitations in detecting defects smaller than 30 nanometers and inefficiencies in handling non-repeating inspected patterns.
Innovation Solution
The implementation of a redesigned filler cell in the circuit layout, which includes a systematic design of experiments based on existing and potential process failure modes, enhances e-beam inspection sensitivity and throughput by converting irregular logic patterns into repeated arrays, thereby improving defect detection capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If e-beam inspection is used to detect smaller defects (down to 3nm), then measurement precision is improved, but inspection sensitivity and throughput deteriorate
Solution Approach 1:
The inspection area is segmented into functional cells and non-functional cells. Non-functional cells are further segmented into filler cells containing repeated patterns. This segmentation allows the inspection system to focus computational resources on comparing functional cells against a library of non-functional cell patterns, enabling high-resolution defect detection while maintaining throughput through efficient pattern matching.
2Measurement precision
If e-beam inspection is used to detect smaller defects, then measurement precision is improved, but analysis cycle time increases
Solution Approach 1:
Non-functional cell patterns are pre-processed and stored in a library before inspection. During inspection, functional cells are compared against this pre-prepared library using efficient algorithms. This preliminary preparation of reference patterns significantly reduces the computational time required during actual inspection, thereby reducing analysis cycle time while maintaining high measurement precision.
3Manufacturing precision
If irregular logic patterns are inspected, then manufacturing precision is maintained, but device complexity increases due to non-repeating patterns
Solution Approach 1:
The invention creates copies of non-functional cell patterns (filler cells) and stores them in a library. During inspection, these copied patterns are used as reference templates to compare against functional cells. This copying approach simplifies the inspection process by replacing complex unique pattern matching with efficient template comparison, reducing device complexity while maintaining manufacturing precision.
Data Source
AI summary
Provided is a method for inserting a pre-designed filler cell, as a replacement to a standard filler cell, including identifying at least one gap among a plurality of functional cells. In some embodiments, a pre-designed filler cell is inserted within the at least one gap. By way of example, the pre-designed filler cell includes a layout design having a pattern associated with a particular failure mode. In various embodiments, a layer is patterned on a semiconductor substrate such that the pattern of the layout design is transferred to the layer on the semiconductor substrate. Thereafter, the patterned layer is inspected using an electron beam (e-beam) inspection process.