Hybrid IMD Structure Adhesion Layer for Semiconductor Reliability
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Solution Overview
Problem
The semiconductor industry faces challenges in achieving optimal adhesion and mechanical strength in hybrid inter-metal dielectric (IMD) structures due to the limitations of existing materials and processes, particularly in reducing dielectric constant and improving integration density as feature sizes decrease.
Innovation Solution
The implementation of a hybrid IMD structure comprising an adhesion layer with a dielectric constant of 4.0 or less and a porous insulating material layer with a dielectric constant of 2.6 or less, formed using plasma-enhanced chemical vapor deposition (PECVD), where the adhesion layer is optimized for stress and porosity to enhance adhesion and mechanical strength through UV exposure, creating a delta-stress range of +10 to +30 MPa.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If low dielectric constant materials are used to reduce capacitance and improve integration density, then device performance is improved, but adhesion strength and mechanical reliability deteriorate
Solution Approach 1:
The patent uses a composite IMD structure combining ELK material (dielectric constant ≤2.6) with a silicon oxide layer (dielectric constant ≤4.0). This composite approach allows the ELK material to provide low capacitance for improved device performance while the silicon oxide layer provides mechanical strength and adhesion, resolving the contradiction between low dielectric constant requirements and adhesion strength requirements
Solution Approach 2:
The patent applies different material properties to different regions of the IMD structure: the ELK material is used where low dielectric constant is critical for capacitance reduction, while the silicon oxide layer is applied specifically where mechanical strength and adhesion are needed. This local differentiation allows each material to optimize its function without compromising the other
2Quantity of substance
If ELK material with dielectric constant ≤2.6 is used to achieve low capacitance, then integration density is improved, but adhesion to underlying layers deteriorates
Solution Approach 1:
The silicon oxide layer acts as an intermediary between the ELK material and the underlying substrate or conductive layers. This intermediate layer provides a bonding interface that adheres well to both the ELK material and the underlying structures, resolving the adhesion problem while allowing the ELK material to maintain its low dielectric constant property for high integration density
3Reliability
If porous insulating material is used to reduce dielectric constant, then capacitance is reduced, but mechanical strength and structural integrity deteriorate
Solution Approach 1:
The patent combines porous ELK material (which provides low dielectric constant and capacitance) with a denser silicon oxide layer (which provides mechanical strength). The composite structure allows the porous ELK material to achieve capacitance reduction while the silicon oxide layer compensates for the mechanical strength loss, resolving the contradiction between capacitance performance and structural integrity
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 significantly improves adhesion by over 5% to 25% and reduces package failure rates, while maintaining low dielectric constants and capacitance performance, thereby enhancing the integration density and reliability of semiconductor devices.
Implementation Method 1
formed using plasma-enhanced chemical vapor deposition (PECVD)
Implementation Method 2
UV exposure, creating a delta-stress range of +10 to +30 MPa
Data Source
AI summary
Semiconductor devices, methods of manufacture thereof, and IMD structures are disclosed. In some embodiments, a semiconductor device includes an adhesion layer disposed over a workpiece. The adhesion layer has a dielectric constant of about 4.0 or less and includes a substantially homogeneous material. An insulating material layer is disposed over the adhesion layer. The insulating material layer has a dielectric constant of about 2.6 or less. The adhesion layer and the insulating material layer comprise an IMD structure.