Non-Planar Fin Transistor Buttressing for Fracture Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Manufacturing high aspect ratio finFETs is challenging due to mechanical stresses during substrate movement and cleaning, which can cause fin fracturing, making it difficult to construct thin and tall fins effectively.
Innovation Solution
The manufacturing process involves forming a first wall of the fin and supporting it with a buttressing material before forming the second wall, which helps prevent fracturing by limiting strain and mechanical forces during the manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If high aspect ratio fins are constructed to reduce manufacturing costs and increase integration density, then the area per transistor decreases, but the fins become susceptible to fracturing during manufacturing due to concentrated mechanical stresses
Solution Approach 1:
The method forms a first wall of the fin structure before forming the second wall, and supports the first wall with buttressing material during the manufacturing process. This preliminary action provides mechanical support to the vulnerable first wall before it can fracture under stress during subsequent processing steps.
Solution Approach 2:
The buttressing material acts as an intermediary element that provides mechanical support to the first wall of the fin structure. This intermediate material prevents direct transmission of mechanical stresses to the fin wall, thereby preventing fracturing while allowing the fin to maintain its high aspect ratio geometry.
2Productivity
If thin and tall fins are formed to improve transistor integration density, then more transistors can be packed into a given area, but the fins encounter larger internal stresses that concentrate at the base making them prone to fracture
Solution Approach 1:
The first wall is formed and supported with buttressing material before the second wall is formed. This preliminary support structure is in place before the fin reaches its full height and becomes vulnerable to the concentrated stresses that arise from its thin and tall geometry.
Solution Approach 2:
The buttressing material is applied locally at the base of the first wall where stresses are most concentrated. This localized support provides reinforcement exactly where needed to prevent fracturing, without affecting the overall thin and tall geometry of the fin structure.
3Ease of manufacture
If conventional fin formation methods are used without buttressing support, then the manufacturing process is simpler, but the fins are highly susceptible to fracturing during substrate movement and cleaning operations
Solution Approach 1:
The buttressing material is deposited onto the first wall before any subsequent manufacturing steps that might subject the fin to mechanical stresses. This preliminary protective measure ensures the fin is supported during substrate movement and cleaning operations without requiring complex modifications to the overall manufacturing process.
Solution Approach 2:
The buttressing material serves as a cushioning element that is in place before mechanical stresses are applied during manufacturing. This beforehand cushioning absorbs and distributes the inertial forces during substrate movement and fluid forces during cleaning, preventing these harmful factors from fracturing the fin.
Data Source
AI summary
Methods for fabricating a non-planar transistor. Fin field effect transistors (finFETs) are often built around a fin (e.g., a tall, thin semiconductive member). During manufacturing, a fin may encounter various mechanical stresses, e.g., inertial forces during movement of the substrate and fluid forces during cleaning steps. If the forces on the fin are too large, the fin may fracture and possibly render a transistor inoperative. Supporting one side of a fin before forming the second side of a fin creates stability in the fin structure, thereby counteracting many of the mechanical stresses incurred during manufacturing.