3D IC Thermal Dissipation Structure Using Graded DLC Layer
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Solution Overview
Problem
Existing 3D IC structures face thermal dissipation issues, leading to bonding and stress problems that affect overall performance and reliability.
Innovation Solution
The integration of a diamond-like carbon (DLC) layer with varying grain sizes, featuring a fine grain size top portion and large grain size bottom portion, is used to enhance thermal dissipation and facilitate bonding between substrates, while also serving as a gate isolation layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional bonding structure is used in 3D IC packaging, then the stacking and bonding of multiple chips can be achieved, but thermal dissipation issues arise leading to bonding and stress problems
Solution Approach 1:
A dedicated thermal dissipation layer is introduced as an intermediary component between the bonded chips. This layer serves as a mediator that conducts heat away from the bonding interface, preventing thermal accumulation that would otherwise compromise bonding reliability. The thermal dissipation layer is specifically positioned at the bonding interface to address the thermal management issue without interfering with the bonding process.
Solution Approach 2:
The thermal conductivity parameter of the bonding interface region is enhanced by incorporating the thermal dissipation layer. This parameter change allows the structure to efficiently conduct and dissipate heat, transforming the thermal management capability of the 3D IC package. The layer modifies the thermal properties of the bonding region, enabling effective heat flow paths that prevent thermal-induced bonding failures.
2Device complexity
If thermal dissipation is not addressed in 3D IC structures, then the structure can be simplified, but thermal accumulation causes bonding and stress issues
Solution Approach 1:
The thermal dissipation layer acts as a specialized intermediary component that addresses thermal accumulation without significantly increasing overall structural complexity. It is integrated into the existing 3D IC bonding architecture, adding a functional layer that manages heat while maintaining compatibility with the stacking and bonding process.
Solution Approach 2:
The thermal dissipation layer is designed to manage thermal effects that arise during operation. By providing a dedicated thermal conduction path, the layer accommodates thermal expansion and contraction stresses that would otherwise propagate through the bonding interface, reducing stress-related reliability issues.
3Ease of manufacture
If a uniform grain size structure is used, then the manufacturing process is simpler, but thermal conductivity and surface roughness are not optimized
Solution Approach 1:
The thermal dissipation layer employs a non-uniform grain size structure where different regions have different grain dimensions. This local quality variation optimizes thermal conductivity in specific areas while controlling surface roughness characteristics. The grain size distribution is engineered to enhance heat conduction paths while maintaining appropriate surface properties for bonding.
Solution Approach 2:
The thermal dissipation layer utilizes a composite microstructure with varying grain sizes within the same material phase. This composite approach allows optimization of both bulk thermal conductivity and surface characteristics, achieving enhanced thermal management performance while maintaining manufacturability through controlled material processing.
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
The DLC layer improves thermal conductivity, reduces surface roughness, and enhances bonding strength, resulting in improved device performance and reliability of 3D IC structures.
Implementation Method 1
The thermal dissipation structure includes a diamond-like carbon (DLC) layer... The DLC layer improves thermal conductivity
Implementation Method 2
The DLC layer includes a bottom portion having large grain sizes and a top portion having fine DLC grain sizes... reduces surface roughness
Implementation Method 3
bonding the second substrate to the circuit structure such that the thermal dissipation structure is interposed between the first and second substrates... enhances bonding strength
Data Source
AI summary
The present disclosure provides an integrated circuit (IC) structure in accordance with some embodiments. The IC structure includes a circuit structure having semiconductor devices formed on a first substrate, an interconnect structure over the semiconductor devices; and a thermal dissipation structure formed on a second substrate. The second substrate is boned to the circuit structure such that the thermal dissipation structure is interposed between the first and second substrates. The thermal dissipation structure includes a diamond-like carbon (DLC) layer. The DLC layer includes a bottom portion having large grain sizes and a top portion having fine DLC grain sizes.