Air Gap Spacer Reduces Parasitic Capacitance in Semiconductor Devices
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Solution Overview
Problem
As semiconductor devices shrink in size and performance increases, the reduced interval between wiring patterns leads to increased parasitic capacitance, which existing technologies have not effectively addressed.
Innovation Solution
The introduction of air gaps with low dielectric constants as spacers between wiring patterns, formed through specific trench and capping pattern configurations, to reduce parasitic capacitance and enhance semiconductor device performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the interval between wiring patterns is reduced to increase device density, then the quantity of devices per area increases, but parasitic capacitance increases
Solution Approach 1:
An air gap spacer is introduced as an intermediary material between adjacent wiring patterns. This air gap, having a dielectric constant close to 1, acts as a mediator that reduces the electrical coupling between neighboring wires, thereby decreasing parasitic capacitance while allowing the wiring patterns to remain in close proximity for high device density
Solution Approach 2:
The dielectric constant parameter of the material between wiring patterns is changed from conventional dielectric materials (with higher k-values) to air (with k≈1). This parameter change fundamentally reduces the capacitance formed between adjacent wiring patterns, enabling reduced spacing without proportionally increasing parasitic capacitance
2Object-generated harmful factors
If air gap spacers are introduced to reduce parasitic capacitance, then parasitic capacitance decreases, but device complexity increases
Solution Approach 1:
The air gap spacer structure is formed preliminarily during the interlayer insulating film formation process. By preparing the air gap structure in advance through selective etching and filling operations before subsequent wiring formation, the patent avoids the need for additional complex processes later, thereby managing fabrication complexity while achieving the parasitic capacitance reduction goal
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 use of air gaps effectively reduces parasitic capacitance, improving the yield and performance of semiconductor devices by minimizing electrical isolation issues between wiring patterns.
Implementation Method 1
By using an air gap, which has a low dielectric constant, as a spacer between wiring patterns, the parasitic capacitance can be reduced.
Data Source
AI summary
A method for fabricating a semiconductor device includes providing a substrate including a cell region including a bit line structure, a bit line spacer and a lower electrode and a peripheral circuit region including first to third impurity regions, forming an interlayer insulating film on the peripheral circuit region, forming a first metal layer on the interlayer insulating film, forming a first trench and a second trench in the first metal layer between the first and second impurity regions, the second trench is disposed between the second and third impurity regions and exposes the interlayer insulating film, forming a first capping pattern on the first trench to form an air gap in the first trench, filling the second trench with a first insulating material, and forming, on the first metal layer, a contact connected to the third impurity region.