Dielectric Densification Using Supercritical Radical Treatment
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Solution Overview
Problem
Existing semiconductor fabrication processes face challenges in achieving dielectric material density and uniformity without increasing the thermal budget or damaging existing structures, particularly in stacked multi-gate devices where annealing processes can cause threshold voltage shifting and On-state current degradation.
Innovation Solution
A low-thermal-budget treatment method using supercritical carbon dioxide to carry hydrogen or oxygen radicals for densifying dielectric materials, which modifies Si—O—Si bonding and improves planarization without high temperatures, utilizing a treatment system with a process chamber, autoclave, and gas sources to generate radicals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If annealing processes are used to improve dielectric material density and uniformity, then the quality of the dielectric material is improved, but the thermal budget increases and electrical performance of existing structures is impacted
Solution Approach 1:
The patent changes the physical-chemical parameters of the dielectric material by introducing nitrogen and carbon species through plasma treatment or chemical vapor deposition. This modifies the dielectric material's composition and structure at lower temperatures, achieving densification without relying on high-temperature annealing processes, thus resolving the contradiction between improving material quality and maintaining low thermal budget
Solution Approach 2:
The patent uses plasma or chemical vapor deposition as an intermediary process to introduce nitrogen and carbon species into the dielectric material. This intermediary treatment enables densification and uniformity improvement without directly applying high heat, thereby avoiding the thermal damage to existing structures while still achieving the desired material quality
2Manufacturing precision
If annealing processes are used to improve dielectric material quality, then etching and planarization rates become more predictable, but damage occurs to sensitive structures like metal gates and metal lines
Solution Approach 1:
The patent modifies the dielectric material's chemical composition by incorporating nitrogen and carbon species through plasma or CVD treatment. This compositional change improves the material's etching and planarization characteristics without requiring high-temperature annealing, thus achieving predictable processing rates while protecting sensitive metal structures from thermal damage
Solution Approach 2:
The patent replaces the thermal mechanism (annealing) with a chemical mechanism (plasma or CVD treatment). Instead of using heat to modify the dielectric material, the invention uses chemical reactions to introduce nitrogen and carbon species, achieving the same densification effect without the harmful thermal impact on metal gates and lines
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 method effectively densifies dielectric layers at lower temperatures, improving etch and planarization uniformity while minimizing damage to sensitive structures like metal gates and metal lines, reducing thermal budget and maintaining electrical performance.
Implementation Method 1
treating the dielectric material with a gaseous species carried in a supercritical fluid
Implementation Method 2
An autoclave receives a gas from the gas source and the supercritical fluid from the heat exchanger to form a gas radical
Implementation Method 3
a heat exchanger configured to cool or heat up the carrier fluid from the carrier fluid source to a temperature greater than a supercritical temperature of the carrier fluid
Implementation Method 4
a pump configured to pump the carrier fluid from the heat exchanger to a pressure greater than a supercritical pressure of the carrier fluid
Data Source
AI summary
A low thermal budget dielectric material treatment is provided. An example method of the present disclosure includes providing a semiconductor structure, depositing a dielectric material over the semiconductor structure, treating the dielectric material with a gaseous species carried in a supercritical fluid, and after the treating, reducing a thickness of the dielectric material.