Semiconductor Device Dummy Region Stress Compensation
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Solution Overview
Problem
The uneven stress applied by the element isolating region to transistor channel forming regions due to differences in channel width and distance leads to deteriorated transistor characteristics in semiconductor devices.
Innovation Solution
Incorporating a dummy region between transistor forming regions and the element isolating region to even out the stress by adjusting the distance between the channel forming regions and the element isolating region, thereby maintaining consistent stress across the channel widths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If transistor forming regions with different channel widths are provided in the element forming region, then the transistor can accommodate different current requirements, but the stress applied to the channel forming region becomes uneven due to different distances from the element isolating region
Solution Approach 1:
The patent introduces a dummy region with specific material properties adjacent to the element isolating region. This dummy region has different stress characteristics than the transistor forming regions, creating a localized stress compensation zone. The dummy region's presence modifies the stress distribution locally near the element isolating region, ensuring that transistor forming regions at different positions experience more uniform stress levels.
Solution Approach 2:
The dummy region acts as an intermediary structure between the element isolating region and the transistor forming regions. By positioning the dummy region adjacent to the element isolating region, it mediates the stress transmission from the isolating region to the transistor channels, preventing direct uneven stress application to transistor forming regions with different channel widths.
2Area of stationary object
If the distance between channel forming region and element isolating region is reduced to improve device integration, then the device density increases, but the stress applied to the channel forming region increases and becomes more uneven
Solution Approach 1:
The dummy region serves as a stress-mediated intermediary structure positioned between the element isolating region and the transistor forming regions. Even when transistor forming regions are positioned close to the element isolating region for high density, the dummy region intercepts and redistributes the stress field, preventing direct stress concentration on the channel forming regions and maintaining stress uniformity despite reduced distances.
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 improves the transistor characteristics by ensuring even stress distribution, which enhances the mobility coefficient and prevents deterioration of transistor performance.
Implementation Method 1
the channel forming region may be stressed by the element isolating region because of a difference in a rate of thermal expansion. The stress influences mobility of a carrier (an electron or hole) in the channel forming region.
Data Source
AI summary
To suppress stress variation on a channel forming region, a semiconductor device includes an element isolating region on the semiconductor substrate principal surface, and an element forming region on the principal surface to be surrounded by the element isolating region. The principal surface has orthogonal first and second directions. A circumferential shape of the element forming region has a first side extending along the first direction. The element forming region has a first transistor region (TR1), a second transistor region (TR2) arranged between the first side and TR1, and a dummy region on the first direction side of TR1. TR1 has a first channel forming region facing the first side. TR2 has a second channel forming region facing the first side. The first channel forming region has a non-facing region that is not facing the second channel forming region. The dummy region faces the non-facing region in the second direction.