Multi-Pulse ALD Gap Filling for High-Aspect-Ratio Semiconductor Structures
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for filling gaps in high aspect ratio semiconductor structures, such as atomic layer deposition, often result in voids or seams due to overhang formation at the pattern top, requiring high-temperature processes and additional deposition-etching cycles, which degrade device performance and reduce productivity.
Innovation Solution
An atomic layer deposition method using pulsed or non-pulsed source RF power and pulsed bias RF power to control the ON-OFF states, with adjustable power intensities and frequencies, to generate plasma and optimize the deposition process, preventing overhang formation and improving gap-filling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional atomic layer deposition is used to fill gaps in high aspect ratio structures, then deposition occurs, but overhang formation causes voids or seams inside the structure
Solution Approach 1:
The patent applies pulsed plasma cycles with multiple pulses within each ALD cycle. The plasma is turned on and off periodically, creating distinct deposition phases. This periodic action allows reactive species to penetrate deep into high aspect ratio structures during plasma-on phases while preventing overhang formation during plasma-off phases, achieving complete gap filling without voids or seams
Solution Approach 2:
The patent modifies deposition parameters by using multiple plasma pulses with controlled durations and intervals. By adjusting the number of pulses, pulse width, and plasma power, the deposition profile changes from top-heavy (overhang) to more uniform or bottom-up filling. This parameter optimization resolves the contradiction between achieving deposition and preventing structural defects
2Reliability
If high-temperature heat treatment is applied to achieve excellent dielectric characteristics, then material quality improves, but device performance degrades due to thermal stress in high aspect ratio structures
Solution Approach 1:
The patent changes the temperature parameter from high-temperature processing to low-temperature ALD (typically 100-400°C). By optimizing plasma power and pulse conditions, excellent dielectric characteristics are achieved without subjecting high aspect ratio structures to thermal stress, thereby preventing device performance degradation
3Manufacturing precision
If additional deposition-etching-deposition cycles are performed to solve overhang problem, then overhang is reduced, but productivity decreases due to low throughput
Solution Approach 1:
The patent merges multiple deposition actions into a single ALD cycle by implementing multiple plasma pulses within one cycle. Instead of performing separate deposition-etching-deposition cycles, the multi-pulse approach achieves overhang control and complete gap filling within the ALD process itself, significantly improving throughput and productivity
4Productivity
If faster deposition rate is used to improve productivity, then throughput increases, but overhang formation at pattern top worsens
Solution Approach 1:
The patent uses periodic plasma pulsing to maintain fast overall deposition rates while controlling overhang. During plasma-on phases, deposition occurs rapidly; during plasma-off phases, reactive species distribution equalizes and overhang formation is prevented. This periodic modulation allows high productivity without sacrificing overhang control
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
The method effectively fills gaps in high aspect ratio semiconductor structures without forming voids or seams, enhancing device performance and productivity by allowing bottom-up deposition and reducing the need for thermal treatment processes.
Implementation Method 1
supplying a process gas to an inside of the chamber, generating plasma in a reaction space above the substrate by applying pulsed or non-pulsed source RF power
Implementation Method 2
applying pulsed bias RF power
Data Source
AI summary
One embodiment of the present invention provides an atomic layer deposition device for filling a gap of a semiconductor structure with a high aspect ratio and a method of manufacturing the same. According to the atomic layer deposition method of filling the gap of the semiconductor structure with the high aspect ratio according to one embodiment of the present invention, it is possible to remove an overhang at an pattern top at the same time as deposition and perform the gap-filling to remove a void and a seam by improving bottom-up deposition in a high aspect ratio structure of 40:1 or more.