Hybrid Bonding Die Distribution for Copper Recess Matching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in semiconductor manufacturing is the variability of copper recess depths during chemical-mechanical polishing (CMP) on larger wafers, leading to inconsistent gaps in hybrid bonding, which affects yield and electrical performance when combining dies from wafers of different sizes.
Innovation Solution
Implementing variable CMP processes on smaller wafers to create a range of recess depths, using a die pairing model to match dies with uniform combined gaps, followed by batch annealing under consistent conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If standard CMP process is used on larger wafers, then production capacity is maintained, but copper recess depth variability increases leading to inconsistent bonding gaps
Solution Approach 1:
The patent segments the wafer processing by dividing larger wafers into multiple smaller processing zones or treating them as multiple smaller wafers. This segmentation allows the CMP process to be optimized for each segment, maintaining uniform copper recess depths across the entire wafer surface while preserving the ability to process large wafer areas for high productivity.
Solution Approach 2:
The patent applies local quality by implementing location-dependent CMP parameters across the wafer surface. Different regions of the wafer receive customized polishing conditions (pressure, speed, slurry flow) to compensate for radial and positional variations, ensuring uniform copper recess depths throughout the wafer while maintaining overall processing efficiency.
2Adaptability or versatility
If dies from wafers of different sizes are combined, then design flexibility and device integration are improved, but bonding consistency deteriorates due to varying copper recess depths
Solution Approach 1:
The patent changes the parameters of the CMP process based on wafer size and die location. By adjusting polishing pressure, speed, and duration as parameters, the process compensates for the inherent variability when combining dies from different wafer sizes, ensuring that all dies achieve uniform copper recess depths regardless of their source wafer dimensions.
Solution Approach 2:
The patent performs preliminary characterization of copper recess depths on each wafer before die pairing. This preliminary measurement and mapping allow the system to pre-determine optimal pairings that compensate for variability, matching dies with complementary recess depth profiles to achieve uniform combined bonding gaps while maintaining design flexibility.
3Ease of manufacture
If copper recess depths are not uniformly controlled, then manufacturing complexity is reduced, but electrical performance and bonding yield deteriorate
Solution Approach 1:
The patent implements feedback control in the CMP process by continuously monitoring copper recess depths during polishing and using this information to dynamically adjust process parameters. This closed-loop feedback system maintains uniform recess depths across wafers and throughout production, ensuring high bonding yield while keeping the manufacturing process manageable through automated control.
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 enhances yield and consistency in hybrid bonding by minimizing copper recess gap variations, allowing for high-yield production of semiconductor devices.
Implementation Method 1
An annealing process is executed to bond the paired dies such that corresponding dielectric surfaces bond with each other and corresponding metal materials within corresponding combined metal recesses expand to bond with each other
Implementation Method 2
corresponding metal materials within corresponding combined metal recesses expand to bond with each other
Implementation Method 3
a first chemical-mechanical polishing (CMP) process is executed on the first wafer to recess the surface of the first metal material below the surface of the first dielectric material
Data Source
AI summary
A method of hybrid bonding includes accessing first dies sourced from a first wafer, accessing second dies sourced from a second wafer and accessing third dies sourced from a third wafer. The first, second and third dies each include a respective bonding surface that includes a respective metal material recessed below a surface of a respective dielectric material. The first wafer has a larger diameter than the second and third wafers. An average metal recess depth of the second dies differs from an average metal recess depth of the third dies. A die pairing process is executed that matches the first dies with the second and third dies to form paired dies having combined metal recess depths within a range. An annealing process is executed to bond the paired dies such that corresponding dielectric surfaces bond with each other and corresponding metal materials expand to bond with each other.