Trench Gap Filling with Sequential Reactants to Prevent Voids
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Solution Overview
Problem
The existing methods for filling trenches in integrated circuits often result in void formation, which compromises device isolation and structural integrity, and attempting to prevent voids can limit device packing density and require size constraints on trenches.
Innovation Solution
A method involving a deposition process in a reaction chamber where first and second reactants form monolayers that react in an overlap area at the top of the gap, while a third reactant fills the initially unreacted area at the bottom, ensuring complete filling from the bottom upwards, using a semiconductor processing apparatus with controlled reactant dosing and plasma activation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional trench filling methods are used, then filling speed is improved, but void formation occurs compromising device isolation and structural integrity
Solution Approach 1:
The filling process is divided into multiple sequential steps using different reactants: first reactant forms initial monolayer, second reactant forms additional monolayer with overlap, and third reactant fills remaining areas. This segmentation allows each reactant to perform a specific function, ensuring complete filling without voids while maintaining filling efficiency
Solution Approach 2:
The first and second reactants are introduced in advance to form monolayers on the trench surface before the third reactant is introduced. This preliminary action prepares the surface by creating reactive sites that guide the third reactant to fill only the unreacted areas, preventing void formation from the start
2Object-affected harmful factors
If trench depth is decreased to prevent void formation, then void formation is reduced, but device isolation effectiveness is reduced
Solution Approach 1:
Different regions of the trench receive different treatments: the top area receives monolayer formation from first and second reactants, while the bottom unreacted area receives filling from the third reactant. This local differentiation ensures that each region is filled appropriately without compromising overall trench filling quality or device isolation
3Object-affected harmful factors
If trench top opening is increased to prevent void formation, then void formation is reduced, but integrated circuit real estate increases
Solution Approach 1:
The first and second reactants are introduced with doses that would normally be excessive for complete filling, forming monolayers that overlap in the top area. This partial action in the top region (where overlap occurs) combined with the third reactant's action in the bottom region achieves complete filling without requiring enlarged trench openings, thus saving integrated circuit real estate
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 effectively prevents void formation by ensuring complete filling of trenches without compromising device isolation or increasing circuit real estate, allowing for improved device packing density and structural integrity.
Implementation Method 1
introducing a first reactant to the substrate with a first dose, thereby forming no more than about one monolayer by the first reactant on a first area of the surface of the one or more gaps
Implementation Method 2
introducing a second reactant to the substrate with a second dose, thereby forming no more than about one monolayer by the second reactant on a second area of the surface of the one or more gaps
Implementation Method 3
the first and second areas overlap in an overlap area where the first and second reactants react
Implementation Method 4
introducing a third reactant to the substrate with a third dose, the third reactant reacting with the first or second reactant remaining on the initially unreacted area
Data Source
AI summary
There is provided a method of filling one or more gaps by providing the substrate in a reaction chamber and introducing a first reactant to the substrate with a first dose, thereby forming no more than about one monolayer by the first reactant on a first area; introducing a second reactant to the substrate with a second dose, thereby forming no more than about one monolayer by the second reactant on a second area of the surface, wherein the first and the second areas overlap in an overlap area where the first and second reactants react and leave an initially unreacted area where the first and the second areas do not overlap; and, introducing a third reactant to the substrate with a third dose, the third reactant reacting with the first or second reactant remaining on the initially unreacted area.