Amorphizing Semiconductor Projections to Alleviate SOD Stress
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Solution Overview
Problem
The use of spin-on dielectric (SOD) materials like polysilazanes in semiconductor fabrication can introduce stresses in the semiconductor material, leading to defects and their propagation during thermal treatments, which complicates the formation of isolation structures.
Innovation Solution
The method involves forming trenches in a semiconductor substrate, depositing polysilazane within them, and then amorphizing the substrate regions using an implant to reduce crystallinity, followed by thermal processing to convert the polysilazane into a dielectric material, thereby alleviating stresses and preventing defect propagation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If SOD materials are used to fill trenches for isolation structures, then the isolation effect is improved, but stresses are introduced into the semiconductor material causing defects and dislocations during thermal treatments
Solution Approach 1:
The patent applies preliminary action by forming the isolation structure using SOD materials before subsequent thermal processing steps. By completing the isolation structure formation early in the manufacturing process, the stresses introduced by SOD materials are established before any thermal treatments that could propagate defects into active regions, thereby preventing harmful defect propagation while maintaining the isolation effect.
Solution Approach 2:
The patent converts the harmful stresses introduced by SOD materials into a beneficial situation by timing the isolation structure formation to occur before thermal processing steps. The stresses, which would normally propagate defects during thermal treatment, are instead established in a state where subsequent thermal processing does not affect active regions, thereby transforming the potential harm into a non-problematic condition.
2Ease of manufacture
If thermal treatments are applied to convert polysilazane to silicon oxide, then the dielectric material is formed, but defects propagate into the semiconductor material
Solution Approach 1:
The patent applies preliminary action by forming the isolation structure using SOD materials before subsequent thermal processing steps. By completing the isolation structure formation early in the manufacturing process, the stresses introduced by SOD materials are established before any thermal treatments that could propagate defects into active regions, thereby preventing harmful defect propagation while maintaining the isolation effect.
3Manufacturing precision
If trenches are filled with polysilazane and thermally processed, then silicon oxide is formed for isolation, but stresses cause dislocations in the semiconductor material
Solution Approach 1:
The patent applies preliminary action by forming the isolation structure using SOD materials before subsequent thermal processing steps. By completing the isolation structure formation early in the manufacturing process, the stresses introduced by SOD materials are established before any thermal treatments that could propagate defects into active regions, thereby preventing harmful defect propagation while maintaining the isolation effect.
Solution Approach 2:
The patent converts the harmful stresses introduced by SOD materials into a beneficial situation by timing the isolation structure formation to occur before thermal processing steps. The stresses, which would normally propagate defects during thermal treatment, are instead established in a state where subsequent thermal processing does not affect active regions, thereby transforming the potential harm into a non-problematic condition.
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 reduces the occurrence of defects in the semiconductor material during thermal processing, enhancing the reliability of isolation structures and improving the integrity of semiconductor components.
Implementation Method 1
amorphizing at least some of the monocrystalline material within the active region
Implementation Method 2
the polysilazane within the trenches may be converted to silicon oxide by exposing the polysilazane to oxidant and appropriate thermal conditions
Implementation Method 3
converted to silicon oxide by exposing the polysilazane to oxidant and appropriate thermal conditions
Data Source
AI summary
Some embodiments include methods of forming isolation structures. A semiconductor base may be provided to have a crystalline semiconductor material projection between a pair of openings. SOD material (such as, for example, polysilazane) may be flowed within said openings to fill the openings. After the openings are filled with the SOD material, one or more dopant species may be implanted into the projection to amorphize the crystalline semiconductor material within an upper portion of said projection. The SOD material may then be annealed at a temperature of at least about 400° C. to form isolation structures. Some embodiments include semiconductor constructions that include a semiconductor material base having a projection between a pair of openings. The projection may have an upper region over a lower region, with the upper region being at least 75% amorphous, and with the lower region being entirely crystalline.