Nanosheet Inner Spacer Structure for Precise Thickness Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor memory devices face challenges in improving reliability due to limitations in controlling the thickness of inner spacers, which affects the performance and stability of the device.
Innovation Solution
The semiconductor device incorporates a double film inner spacer with materials of different compositions, allowing for effective control of the spacer's thickness. This configuration includes a first inner spacer contacting the source/drain region and a second inner spacer with a different material, both of which are strategically positioned to enhance reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a single-material inner spacer is used, then the manufacturing process is simple, but the thickness control precision is insufficient
Solution Approach 1:
The inner spacer is divided into two distinct portions: a first inner spacer portion and a second inner spacer portion. Each portion is formed from a different material deposited at different times, allowing independent thickness control of each segment. This segmentation enables precise overall thickness control while maintaining manufacturing feasibility through sequential deposition processes.
Solution Approach 2:
The inner spacer is constructed as a composite structure combining two different materials. The first material forms the first inner spacer portion, and the second material forms the second inner spacer portion. This composite approach allows exploitation of different material properties for different functional requirements while achieving superior thickness control precision.
2Reliability
If the inner spacer thickness is increased to improve reliability, then device stability improves, but the manufacturing control difficulty increases
Solution Approach 1:
By segmenting the inner spacer into two controllable portions with different materials, the manufacturing process can independently optimize the thickness of each portion. This enables achieving the required total thickness for reliability while maintaining precise control over each segment's contribution to the overall dimension.
Solution Approach 2:
The invention changes the material parameter of the inner spacer by using two different materials with distinct deposition characteristics. This allows independent adjustment of thickness parameters for each portion during the manufacturing process, enabling precise control of the total thickness to meet reliability requirements.
Data Source
AI summary
A semiconductor device is provided. The semiconductor device includes a substrate, an active pattern extending in a first horizontal direction on the substrate, a plurality of nanosheets stacked to be spaced apart from each other in a vertical direction on the active pattern, a gate electrode extending in a second horizontal direction different from the first horizontal direction on the active pattern, the gate electrode surrounding the plurality of nanosheets, a source/drain region disposed on at least one side of the gate electrode on the active pattern, a first inner spacer disposed between the source/drain region and the gate electrode between the plurality of nanosheets, the first inner spacer being in contact with the source/drain region, and a second inner spacer disposed between the first inner spacer and the gate electrode between the plurality of nanosheets, the second inner spacer including a material different from a material of the first inner spacer, each of an upper surface and a lower surface of the second inner spacer being in contact with the first inner spacer.