Air Spacer Contact Plug for DRAM Parasitic Capacitance
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Solution Overview
Problem
In DRAM devices, parasitic capacitance occurs between neighboring conductive pads due to the conductive contact plug, which needs to be reduced for improved performance.
Innovation Solution
A semiconductor device design featuring a conductive contact plug with a lower portion and an upper portion of narrower width, where air spacers are used between the conductive contact plug and the adjacent conductive pad to decrease parasitic capacitance, and a capping pattern covers the upper portion of the conductive contact plug.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conductive contact plug is formed under a bit line structure to contact an active pattern, then electrical connection is achieved, but parasitic capacitance occurs between neighboring conductive pads
Solution Approach 1:
An air spacer is introduced as an intermediary substance between the conductive contact plug and the conductive pad. This air spacer acts as a dielectric medium that reduces the parasitic capacitance formed between the conductive contact plug and the conductive pad, while still allowing the bit line structure to maintain electrical connection with the active pattern through the conductive contact plug.
Solution Approach 2:
The air spacer is selectively positioned only in specific locations where parasitic capacitance is most problematic - between the conductive contact plug and the conductive pad. This localized approach reduces parasitic capacitance where it matters most without affecting the overall electrical connection functionality of the device.
2Object-generated harmful factors
If the width of the conductive contact plug is reduced to minimize parasitic capacitance, then capacitance decreases, but manufacturing precision requirements increase
Solution Approach 1:
The air spacer serves as a mediator that allows the conductive contact plug to maintain its necessary width for reliable electrical connection while still reducing parasitic capacitance. The air spacer fills the gap between the conductive contact plug and conductive pad, providing capacitance reduction without requiring precise width control of the conductive contact plug itself.
Solution Approach 2:
The space between the conductive contact plug and conductive pad is segmented by introducing the air spacer. This segmentation allows the conductive contact plug to maintain its functional width while the air spacer occupies the remaining space, effectively reducing the parasitic capacitance without imposing strict width control requirements on the conductive contact plug.
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 air spacer effectively reduces parasitic capacitance between the conductive contact plug and the conductive pad, enhancing the semiconductor device's performance by minimizing electrical interference.
Implementation Method 1
a parasitic capacitance may occur between neighboring conductive pads. Thus, it is desired to reduce the parasitic capacitance in the DRAM device
Data Source
AI summary
A semiconductor device includes a conductive contact plug disposed on a substrate, a bit line structure disposed on the conductive contact plug, first and second spacers, and a capping pattern disposed on the first and second spacers. The conductive contact plug includes a lower portion that has a first width and an upper portion that has a second width narrower than the first width. The bit line structure includes a conductive structure and an insulation structure stacked in a vertical direction. The first and second spacers are stacked on a sidewall of the lower portion of the conductive contact plug in a horizontal direction. The capping pattern covers a sidewall of the upper portion of the conductive contact plug. The first spacer directly contacts the sidewall of the lower portion of the conductive contact plug and includes air.