Strained Semiconductor Layer Homogeneity via Masked Recrystallization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for producing strained semiconductor layers often result in inhomogeneous crystalline orientation and discontinuities due to creep phenomena and rotation of crystalline seeds during recrystallization, leading to suboptimal performance in transistor devices.
Innovation Solution
A method involving the formation of a stack with a mask having symmetrical blocks to protect specific regions during ion implantation and recrystallization, ensuring crystallization without rotation and limiting creep phenomena, thereby achieving a more homogeneous strained semiconductor layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ion implantation and recrystallization are used to produce strained semiconductor layers, then the semiconductor layer can be strained to improve transistor performance, but creep phenomena and rotation of crystalline seeds occur during recrystallization leading to inhomogeneous crystalline orientation and discontinuities
Solution Approach 1:
The patent divides the semiconductor layer into multiple regions with different crystalline orientations by using selective ion implantation through a patterned mask. This segmentation prevents the rotation of crystalline seeds during recrystallization, as each segment is independently controlled, thereby maintaining crystalline orientation homogeneity while still achieving the desired strain for transistor performance.
Solution Approach 2:
The patent applies preliminary ion implantation to specific regions before the final recrystallization step. This preliminary action modifies the crystalline structure in targeted areas, creating nucleation sites that guide the recrystallization process and prevent random rotation of crystalline seeds, thus ensuring homogeneous crystalline orientation in the final strained layer.
2Manufacturing precision
If the entire second semiconductor layer is made amorphous during ion implantation, then complete relaxation of the first semiconductor layer is achieved, but discontinuities and rotational misalignment occur during subsequent recrystallization
Solution Approach 1:
The patent applies local quality by making only specific regions of the second semiconductor layer amorphous through selective ion implantation, rather than the entire layer. This localized amorphization allows for controlled relaxation of the first semiconductor layer in specific areas while preserving the crystalline structure in other regions, thereby preventing discontinuities and maintaining crystalline structure continuity during recrystallization.
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 results in a strained semiconductor layer with improved crystalline structure homogeneity and quality, enhancing the performance of transistor devices by preventing rotation of crystal seeds and reducing discontinuities, thus producing a better quality strained semiconductor material.
Implementation Method 1
implantations inclined with respect to a normal to the main plane of the substrate, so as to render amorphous over its entire thickness the first semiconductor layer as well as areas of the second semiconductor layer without rendering amorphous one or more regions of the second semiconductor layer protected by the mask
Implementation Method 2
carrying out a recrystallization of the regions rendered amorphous and of the first semiconductor layer rendered amorphous by using said regions of the second semiconductor layer this as starting regions of the recrystallization fronts
Implementation Method 3
implantations inclined with respect to a normal to the main plane of the substrate, so as to render amorphous over its entire thickness the first semiconductor layer as well as areas of the second semiconductor layer
Data Source
Figure 1A~1C
Figure 1D~2
Figure 3~4C
AI summary
A method for producing a layer of semiconductor material comprising the steps of: a) forming a stack comprising a first layer (3) based on a first semiconductor material coated with a second layer (6) based on a second semiconductor material with a lattice parameter different from that of the first semiconductor material, b) creating on the second semiconductor layer a mask (10) having a symmetry, c) making the first semiconductor layer (3) and areas (6') of the second semiconductor layer (6) amorphous without making one or more regions (6a, 6b, 6c) of the second semiconductor layer protected by the mask and arranged respectively opposite the masking block(s) amorphous, d) performing a recrystallization of the regions made amorphous (6a, 6b, 6c) and of the first semiconductor layer, resulting in the first semiconductor layer being constrained.