Semiconductor Structure Protection Layer for Contact Isolation
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Solution Overview
Problem
As semiconductor feature densities increase, the manufacturing of interconnection structures faces challenges in maintaining reliable connections between conductive lines and substrates while minimizing device size and preventing short circuits, which affects device performance and fabrication yield.
Innovation Solution
The method involves forming a semiconductor structure with a substrate, gate structures, source drain structures, and dielectric layers, where a protection layer is used to isolate conductive lines from gate structures during etching, allowing for reduced device size and improved performance by preventing over-etching and short circuits, and enhancing the process window for contact hole formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If feature densities increase to improve integration, then more components can be integrated into a given area, but the widths of conductive lines and spacing between conductive lines must scale smaller which increases manufacturing difficulty and risk of short circuits
Solution Approach 1:
A protection layer is introduced as an intermediary between the conductive line formation process and the gate structure. This protection layer prevents direct contact and potential short circuits between conductive lines and gate structures, enabling safer scaling to smaller dimensions while maintaining manufacturing reliability
Solution Approach 2:
The protection layer is formed preliminarily before conductive line deposition, and etch stops are designed in advance on the gate structure. These preliminary measures enable precise control of conductive line formation by preventing over-etching, thus allowing smaller feature sizes with controlled manufacturing precision
2Area of moving object
If device size is reduced to improve integration, then more devices fit in a given area, but the process window for contact hole formation becomes tighter and overlay requirements become more stringent
Solution Approach 1:
The protection layer serves as a mediator that decouples the contact hole formation process from the gate structure dimensions. By providing a consistent protective barrier, it loosens overlay requirements and expands the effective process window, allowing smaller device areas without proportionally increasing process complexity
Solution Approach 2:
Etch stops are applied locally on the gate structure at specific regions where conductive lines will be formed. This localized modification provides targeted protection without affecting the entire device structure, enabling reduced device area while maintaining adequate process windows for contact hole formation
3Area of stationary object
If conductive lines are placed closer together to improve density, then spacing between conductive lines decreases, but the risk of short circuits between conductive lines and gate structures increases
Solution Approach 1:
The protection layer acts as a physical intermediary barrier between conductive lines and gate structures. This intermediary maintains electrical isolation even when spacing is reduced, enabling higher density interconnects while preserving reliability by preventing short circuits
Solution Approach 2:
Etch stops are formed preliminarily on the gate structure before conductive line deposition. This preliminary action ensures that subsequent etching or processing steps will not penetrate through the gate structure, pre-establishing a safety margin that prevents short circuits even at reduced spacings
Data Source
AI summary
A semiconductor structure includes a substrate, a first gate structure, a first spacer, a source drain structure, a first dielectric layer, a conductor, and a protection layer. The first gate structure is present on the substrate. The first spacer is present on a sidewall of the first gate structure. The source drain structure is present adjacent to the first spacer. The first dielectric layer is present on the first gate structure and has an opening therein, in which the source drain structure is exposed through the opening. The conductor is electrically connected to the source drain structure, in which the conductor has an upper portion in the opening of the first dielectric layer and a lower portion between the upper portion and the source drain structure. The protection layer is present between the lower portion and the first spacer and between the upper portion and the source drain structure.