Multi-element Insulating Layer Formation for Nonvolatile Memory
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Solution Overview
Problem
Current nonvolatile semiconductor devices face challenges in achieving high integration, excellent thickness uniformity, and superior data retention due to issues with bulk traps in the multi-element insulating layers, particularly in silicon oxynitride layers formed by simultaneously supplying silicon, nitrogen, and oxygen sources.
Innovation Solution
A method of forming a nonvolatile memory device involves sequentially supplying a silicon source, a nitrogen source, and an oxygen source to the substrate, with varying amounts of oxygen across multiple cycles to control the element content ratio and energy band gap of the multi-element insulating layer, which is then annealed to minimize bulk traps and enhance data retention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a multi-element insulating layer is formed by simultaneously supplying silicon, nitrogen, and oxygen sources, then the formation process is simple, but the thickness uniformity and element content ratio control are poor
Solution Approach 1:
The patent segments the simultaneous supply of silicon, nitrogen, and oxygen sources into sequential cycles. Each cycle includes distinct steps: supplying silicon source, purging, supplying nitrogen source, purging, and supplying oxygen source. This segmentation enables precise control over the amount of each element incorporated into the multi-element insulating layer while maintaining a relatively simple overall process structure.
2Reliability
If the oxygen content in the multi-element insulating layer is increased to reduce bulk traps, then data retention is improved, but the energy band gap may be adversely affected
Solution Approach 1:
The patent optimizes the oxygen content parameter within a specific range (30-60 at.%) to achieve the desired balance. By controlling the oxygen source supply amount in each cycle and the total number of cycles, the patent creates a multi-element insulating layer with optimized oxygen content that reduces bulk traps while maintaining appropriate energy band gap characteristics for tunneling current control.
3Reliability
If the multi-element insulating layer is annealed to minimize bulk traps, then data retention is enhanced, but the processing time and temperature requirements increase
Solution Approach 1:
The patent performs annealing of the multi-element insulating layer after its formation to reduce bulk traps before subsequent layer formation. This preliminary action ensures that the tunnel insulating layer structure is optimized early in the process, preventing bulk trap formation that would otherwise require more extensive later processing, thereby reducing overall processing time.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach results in a nonvolatile memory device with improved integration, uniform thickness, and enhanced data retention by optimizing the oxygen content and energy band gap of the multi-element insulating layer, reducing bulk traps and leakage, and increasing programming efficiency.
Implementation Method 1
the multi-element insulating layer, which is then annealed to minimize bulk traps and enhance data retention
Data Source
AI summary
A nonvolatile memory device and a method of forming the nonvolatile memory device, the method including forming a tunnel insulating layer on a substrate, wherein forming the tunnel insulating layer includes forming a multi-element insulating layer by a process including sequentially supplying a first element source, a second element source, and a third element source to the substrate, forming a charge storage layer on the tunnel insulating layer, forming a blocking insulating layer on the charge storage layer, and forming a control gate electrode on the blocking insulating layer.