III-V Chip Transfer Structure for Low-Defect Si Integration
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Solution Overview
Problem
The integration of III-V devices with Si-based technologies is hindered by lattice constant and thermal expansion mismatches, leading to crystal defects and performance degradation in semiconductor devices, particularly in RF and optical applications.
Innovation Solution
A method involving the growth of multilayer structures on a semiconductor donor wafer with a template layer and selective removal of sublayers to produce defect-free III-V layers, allowing for the co-integration of III-V and Si-based technologies without requiring simultaneous substrate production, using techniques like nano-ridge engineering and selective area growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If III-V material is grown on crystalline Si substrates, then cost is reduced and flexibility is improved, but crystal defects such as misfit and threading dislocations are formed due to lattice constant and thermal expansion mismatch
Solution Approach 1:
The structure is segmented into distinct functional layers: a Si substrate, a buffer layer, and III-V device layers. The buffer layer acts as an intermediate segment that decouples the direct interface between mismatched materials, allowing the III-V layers to grow with reduced defect formation while maintaining cost advantages of Si substrates.
Solution Approach 2:
A buffer layer is introduced as an intermediary between the Si substrate and III-V material layers. This buffer layer mediates the lattice constant and thermal expansion mismatch, enabling the growth of high-quality III-V devices on Si substrates without direct contact between the mismatched materials, thus reducing dislocation formation.
2Productivity
If III-V material is grown on crystalline Si substrates, then production scalability is improved, but device performance deteriorates due to leakage currents and carrier mobility degradation from defects
Solution Approach 1:
The device structure is segmented with the buffer layer separating the Si substrate from the III-V active regions. This segmentation allows large-scale Si-based production while protecting the III-V device performance by preventing defect propagation from the substrate into the active layers.
Solution Approach 2:
The buffer layer serves as a mediator that enables scalable Si-based manufacturing while protecting device performance. It absorbs the mismatch stress and prevents leakage currents and carrier mobility degradation in the III-V devices, allowing both high productivity and reliability.
3Manufacturing precision
If nano-ridge engineering is used to obtain defect-free III-V layers, then manufacturing precision is improved, but device complexity and process difficulty increase
Solution Approach 1:
The complex nano-ridge structure is extracted and replaced with a simpler planar buffer layer configuration. This extraction maintains the defect-blocking functionality while eliminating the geometric complexity of nano-ridges, resulting in easier fabrication and lower process difficulty while still achieving defect-free III-V layers.
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 production of high-performance semiconductor chips with reduced defects, lower power consumption, and increased flexibility in circuit design, addressing the challenges of lattice mismatch and thermal budget issues in III-V and Si-based technology integration.
Implementation Method 1
an etchant is supplied through the TSV openings for the removal of the first sublayer of the template layer and the release layer of the multilayer structure
Implementation Method 2
The donor wafer is then bonded to a carrier wafer by bonding the first bonding surface to a bonding surface of the carrier wafer
Implementation Method 3
at least one multilayer structure is produced on a semiconductor donor wafer. A first semiconductor layer is grown on the bottom surface of a cavity formed in a support layer
Data Source
Figure 1a~1c
Figure 1d~1f
Figure 1g~1h
AI summary
At least one multilayer structure is produced on a semiconductor donor wafer (1), by growing e.g. group III-V material in a cavity (4) formed in a dielectric support layer (3). A template layer (5,16) is formed that embeds the multilayer structure, and that is formed as a stack of two dielectric sublayers, the bottom sublayer (5) being selectively removable with respect to the top sublayer (16). The multilayer structure furthermore comprises a release layer (10) that is accessible from the sides when the bottom sublayer (5) of the template is removed. The method further comprises the production of a device, for example a heterojunction bipolar transistor on one or more of multilayer structures, and the production of conductive paths connected to said device and terminating in a number of contact pads (20) which are coplanar with a first dielectric bonding surface (S1). The donor wafer (1) is then bonded to a carrier wafer (25) which may be a Si-CMOS wafer comprising active Si-based devices. TSV openings (35) are then produced from the back side of the carrier wafer and an etchant is provided for selectively removing the first sublayer (5) of the template layer and the release layer (10) of the multilayer structure. The etchant is supplied through the TSV openings (35) for the removal of the first sublayer and/or for the removal of the release layer. The donor wafer (1) is thereby released and the carrier wafer (25) is further processed and singulated to form separate semiconductor chips.