Hybrid Substrate with Embedded Insulating Layer
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Solution Overview
Problem
Current techniques for producing hybrid substrates with buried electrically insulating layers and mixed crystallographic orientations are incompatible, as they require interruptions in the insulating layer for epitaxy growth or recrystallization, which is not feasible for continuous layers.
Innovation Solution
A method involving temporary molecular bonding with a reference layer for recrystallization, allowing for the creation of a continuous electrically insulating layer and a mixed layer with predefined crystallographic orientations without interruptions, using techniques like roughening and sacrificial layers to facilitate separation and maintain crystalline quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If techniques are used to produce hybrid substrates with mixed crystallographic orientations, then crystallographic orientation diversity is improved, but the continuity of the electrically insulating layer deteriorates due to required interruptions for epitaxy growth or recrystallization
Solution Approach 1:
The patent applies preliminary action by forming the continuous electrically insulating layer on the substrate before creating the mixed layer with different crystallographic orientations. This preliminary formation of the insulating layer eliminates the need for subsequent interruptions or openings, as the layer is already in place to support epitaxial growth or recrystallization processes. The method sequentially forms: (1) a substrate, (2) a continuous electrically insulating layer on the substrate, and (3) a mixed layer on the insulating layer with zones of different crystallographic orientations, thereby maintaining layer continuity while achieving orientation diversity.
Solution Approach 2:
The patent applies segmentation by dividing the mixed layer into distinct zones with different crystallographic orientations (first orientation and second orientation) that are spatially separated. This segmentation allows each zone to have its specific orientation properties while both zones rest on the same continuous electrically insulating layer, avoiding the need to interrupt the insulating layer for orientation changes. The mixed layer is thus segmented into orientation-specific regions rather than requiring interruptions in the underlying insulating structure.
2Stability of the object's composition
If a continuous electrically insulating layer is maintained without interruptions, then layer integrity is improved, but the ability to perform epitaxial growth or recrystallization deteriorates due to lack of access through the insulating layer
Solution Approach 1:
The patent applies preliminary action by pre-forming the continuous electrically insulating layer on the substrate before creating the mixed layer with different crystallographic orientations. This preliminary formation of the insulating layer eliminates the need for subsequent interruptions or openings, as the layer is already in place to support epitaxial growth or recrystallization processes. The method sequentially forms: (1) a substrate, (2) a continuous electrically insulating layer on the substrate, and (3) a mixed layer on the insulating layer with zones of different crystallographic orientations, thereby maintaining layer continuity while achieving orientation diversity.
3Reliability
If two types of crystallographic orientations are produced on the same substrate, then carrier mobility performance is improved, but manufacturing complexity increases due to the need for multiple processing steps
Solution Approach 1:
The patent applies preliminary action by pre-forming the continuous electrically insulating layer on the substrate before creating the mixed layer with different crystallographic orientations. This preliminary formation of the insulating layer eliminates the need for subsequent interruptions or openings, as the layer is already in place to support epitaxial growth or recrystallization processes. The method sequentially forms: (1) a substrate, (2) a continuous electrically insulating layer on the substrate, and (3) a mixed layer on the insulating layer with zones of different crystallographic orientations, thereby maintaining layer continuity while achieving orientation diversity.
Solution Approach 2:
The patent applies local quality by creating regions with different crystallographic orientations within the mixed layer while maintaining a uniform continuous electrically insulating layer underneath. The mixed layer contains first zones with a first crystallographic orientation and second zones with a second crystallographic orientation, allowing local optimization of carrier mobility for different transistor types (nFET and pFET) while using a single continuous insulating layer structure that simplifies the overall manufacturing process.
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
Enables the reliable and efficient production of hybrid substrates with mixed layers having predefined crystallographic orientations, suitable for CMOS technologies, while maintaining the integrity of the buried electrically insulating layer, allowing for simultaneous production of nFET and pFET transistors.
Implementation Method 1
by bonding the first substrate to a second substrate, the second substrate comprising on the surface a reference layer forming a seed, the bonding being a molecular bonding
Implementation Method 2
a heat treatment is applied to at least the reference layer and to the mixed layer, the heat treatment being suitable for causing the recrystallization of the amorphous material which constitutes the zones
Implementation Method 3
a heat treatment is applied to at least the reference layer and to the mixed layer, the heat treatment being suitable for causing the recrystallization
Implementation Method 4
the free surface of the first substrate is roughened
Data Source
Figure 1~5
Figure 6~9
Figure 10~14
AI summary
The invention relates to a method for producing a hybrid substrate comprising the following steps: - a first substrate (10) is prepared, comprising a mixed layer extended by an underlying electrically insulating continuous layer (11) and made up of first single-crystal areas (12A) and second adjacent areas (12B) in an amorphous material, said second areas making up at least part of the free surface of said first substrate; a second substrate (20) that comprises, on the surface thereof, a reference layer with a predetermined crystallographic orientation, is bonded to said first substrate by hydrophobic molecular bonding at least onto said amorphous areas; recrystallisation of at least part of the amorphous areas to solid phase is carried out according to the crystallographic orientation of the reference layer, and the two substrates are separated at the bonding interface.