Trimmed Channel Fin Structure for Gate Isolation Reliability
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Solution Overview
Problem
As semiconductor device dimensions shrink, manufacturing process deviations lead to increased risks of short circuits and open circuits due to pattern shifts, uneven material deposition, and etch residues, which can cause dielectric breakdown and electrical bridging between conductive elements.
Innovation Solution
The formation of an active area spacer along the sidewall of the semiconductor device, made from a material more resistant to etch processing than the channel region materials, helps reduce short circuits by separating the source and drain regions from the gate electrode and improving the quality of dielectric material, while trimming the isolating fins and depositing a gate electrode spacer to prevent voids and ensure even deposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If semiconductor device dimensions are shrunk to increase integration density, then productivity and device capacity are improved, but manufacturing precision deteriorates due to increased sensitivity to process deviations
Solution Approach 1:
The patent applies preliminary action by forming a mandrel structure and spacer before the final gate electrode deposition. The mandrel is positioned in advance to define the precise location where gate material should be deposited, and the spacer is formed around it to create a protective barrier. This preliminary structuring ensures that even when dimensions are shrunk, the gate electrode maintains correct alignment and spacing, preventing short circuits while enabling higher integration density.
Solution Approach 2:
The patent uses an intermediary approach by introducing a mandrel structure as a temporary mediator during manufacturing. This mandrel serves as a placeholder that guides the deposition of gate electrode material and defines critical dimensions. The mandrel acts as an intermediary between the patterning process and the final gate formation, ensuring precise alignment without requiring direct lithographic patterning at the smallest dimensions, thus maintaining manufacturing precision while enabling device shrinkage.
2Device complexity
If conventional manufacturing processes are used without spacers, then device complexity is reduced, but reliability deteriorates due to short circuits and dielectric breakdown
Solution Approach 1:
The spacer acts as an intermediary protective element between the gate electrode and the dielectric material. It provides a physical barrier that prevents direct contact and potential short circuits, while also ensuring uniform spacing that prevents dielectric breakdown. The spacer material is chosen to be etch-resistant, providing reliable protection throughout subsequent manufacturing steps, thus significantly improving electrical isolation reliability despite the added manufacturing step.
Solution Approach 2:
The patent applies beforehand cushioning by forming the spacer structure in advance to protect against potential manufacturing defects. The spacer creates a buffer zone that compensates for variations in material deposition thickness and etch process deviations. This protective cushion ensures that even when process deviations occur, the gate electrode remains properly isolated from conductive elements, preventing short circuits and maintaining reliability.
3Ease of manufacture
If etch residues are present to simplify the etching process, then ease of manufacture is improved, but reliability deteriorates due to short circuits from conductive bridges
Solution Approach 1:
The spacer serves as an intermediary protective barrier that is formed before the etching process. Its etch-resistant material composition allows it to withstand the etching process that removes other materials, including potential residues. The spacer prevents any conductive material or residues from forming bridges between isolated elements, maintaining electrical isolation reliability even when the etching process is simplified and may leave residues elsewhere in the structure.
Solution Approach 2:
The patent converts the potential harm of etch residues into a benefit by using the spacer as a protective shield. The spacer's position and etch resistance mean that even if residues remain after etching, they are prevented from forming harmful conductive bridges by the spacer barrier. This allows the use of simpler, more aggressive etching processes that would otherwise be too risky, improving ease of manufacture while maintaining reliability.
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 reduces the frequency of short circuits between gate electrodes and source/drain regions, enhances transistor switching speed, and extends device lifetime by preventing voids and electrical bridging, thereby improving the reliability and performance of semiconductor devices.
Implementation Method 1
depositing a gate electrode spacer to prevent voids and ensure even deposition
Implementation Method 2
formation of an active area spacer along the sidewall of the semiconductor device, made from a material more resistant to etch processing than the channel region materials, helps reduce short circuits by separating the source and drain regions from the gate electrode
Data Source
AI summary
A method of making a semiconductor device includes manufacturing an active area fin extending in a first direction over a substrate, wherein the active area fin comprises a source region, a drain region, and a channel region between the source region and the drain region. The method includes manufacturing an isolation structure next to the active area fin. The method includes manufacturing isolating fins next to the active area fin and over the isolation structure. The method includes trimming the isolating fins in first fin regions adjacent to the channel regions of the active area fin. The method includes depositing a gate electrode material against the first fin region and the gate dielectric in the channel region.