Ultra-Thin GaN Die Support During Post-Attach Si Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ultra-thin GaN semiconductor dies are susceptible to cracking and breakage during integration and packaging due to the removal of the supporting Si wafer, which complicates the manufacturing process and affects device performance.
Innovation Solution
A method involving the use of a base substrate material for structural support during the manufacturing and integration of GaN semiconductor dies, where the Si wafer is retained until after the GaN die is attached to an interconnect structure, allowing for stable handling and reduced stress on the GaN substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the Si wafer is removed to achieve high breakdown voltage, then the GaN device breakdown voltage is improved, but the ultra-thin GaN die become susceptible to cracking and breakage during integration and packaging
Solution Approach 1:
The patent applies preliminary action by retaining the Si wafer during integration and packaging processes before removing it at the appropriate stage. The Si wafer is kept as a support structure during critical manufacturing steps, then removed after the GaN die are securely attached to the interconnect structure, preventing cracking and breakage while enabling high breakdown voltage devices
Solution Approach 2:
The Si wafer serves as an intermediary support structure during the manufacturing process. It provides mechanical support to the ultra-thin GaN die during integration and packaging, then is removed after serving its protective function, allowing the GaN device to achieve its full breakdown voltage potential without structural damage
2Strength
If the Si wafer is retained to provide structural support, then the risk of cracking and breakage is reduced, but the breakdown voltage of the GaN device decreases
Solution Approach 1:
The Si wafer is retained during integration and packaging processes as a preliminary support structure, then removed at the appropriate stage after the GaN die are securely attached to the interconnect structure. This timing allows the Si wafer to provide necessary structural support during manufacturing while being removed before final device operation to achieve high breakdown voltage
Solution Approach 2:
The Si wafer is temporarily retained during manufacturing to provide structural support, then discarded (removed) after serving its protective function. This allows the GaN device to achieve high breakdown voltage in the final product while the Si wafer is recovered as a removable intermediate support structure
3Stability of the object's composition
If the GaN substrate is made thicker to compensate for Si removal, then structural stability is improved, but manufacturing cost and stress factors increase
Solution Approach 1:
Instead of making the GaN substrate thicker in advance, the patent uses the Si wafer as a preliminary support structure during manufacturing. This allows the GaN substrate to remain thin (reducing cost and stress) while the Si wafer provides the necessary structural stability during integration and packaging processes
4Reliability
If the Si wafer is removed at the wafer-level before singulation, then the breakdown voltage target is met, but the ultra-thin GaN die are susceptible to damage during subsequent processing
Solution Approach 1:
The patent reverses the conventional sequence by retaining the Si wafer during singulation and integration processes, then removing it at the appropriate stage after the GaN die are securely attached to the interconnect structure. This preliminary retention prevents damage during processing while still achieving the breakdown voltage target in the final device
Solution Approach 2:
The patent inverts the conventional approach by removing the Si wafer at the end of the process rather than at the beginning. Instead of removing the Si wafer before singulation to meet breakdown voltage targets, the Si wafer is retained through singulation and integration, then removed after the GaN die are securely attached, reversing the traditional sequence to avoid damage while achieving performance goals
Data Source
AI summary
A first semiconductor substrate contains a first semiconductor material, such as silicon. A second semiconductor substrate containing a second semiconductor material, such as gallium nitride or aluminum gallium nitride, is formed on the first semiconductor substrate. The first semiconductor substrate and second semiconductor substrate are singulated to provide a semiconductor die including a portion of the second semiconductor material supported by a portion of the first semiconductor material. The semiconductor die is disposed over a die attach area of an interconnect structure. The interconnect structure has a conductive layer and optional active region. An underfill material is deposited between the semiconductor die and die attach area of the interconnect structure. The first semiconductor material is removed from the semiconductor die and the interconnect structure is singulated to separate the semiconductor die. The first semiconductor material can be removed post interconnect structure singulation.