Rapid Curing Semiconductor Polymer Layer via UV Cross-Linking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for curing polymer layers in semiconductor devices require long cure cycles, leading to deformation of via sidewalls and increased processing time, which hinders the production of smaller, more compact semiconductor packages.
Innovation Solution
A two-step method involving UV cross-linking followed by rapid thermal curing using a hot plate, with a maximum ramp-up rate greater than 10 degrees Celsius per minute, to maintain steep via sidewall profiles and reduce curing time to less than 60 minutes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional slow ramp-up thermal curing is used, then via sidewall deformation is prevented, but curing time becomes excessively long
Solution Approach 1:
The curing process is divided into two distinct stages: first, UV irradiation cross-links the polymer layer to stabilize the via sidewalls; second, rapid thermal curing completes the polymerization. This segmentation allows the first stage to prevent sidewall deformation while enabling the second stage to achieve fast curing, resolving the contradiction between precision and time.
Solution Approach 2:
UV cross-linking is performed as a preliminary action before thermal curing to pre-stabilize the via sidewalls. This preliminary cross-linking creates a rigid framework that prevents deformation during the subsequent rapid heating process, allowing fast curing without sacrificing sidewall profile precision.
2Productivity
If rapid thermal curing is used, then curing time is reduced, but via sidewall deformation occurs
Solution Approach 1:
The process segments curing into UV cross-linking followed by rapid thermal curing. The UV stage prepares the polymer structure to withstand rapid heating, while the thermal stage maximizes productivity. This segmentation enables both fast processing and precise sidewall profiles.
Solution Approach 2:
UV irradiation serves as a preliminary stabilizing action that cross-links the polymer chains before rapid heating. This preliminary action creates structural integrity that prevents sidewall deformation during the high-speed thermal curing process, enabling both speed and precision.
3Stability of the object's composition
If UV cross-linking is performed before thermal curing, then via sidewall stability is improved, but process complexity increases
Solution Approach 1:
The UV irradiation and thermal curing steps are merged into an integrated two-step process where UV cross-linking and thermal polymerization work synergistically. The UV stage creates initial stability while the thermal stage completes curing, together achieving superior polymer layer stability without excessive complexity.
Solution Approach 2:
The process utilizes parameter changes by switching from UV irradiation (electromagnetic energy) to thermal heating (thermal energy). This parameter change enables different chemical reactions: UV initiates cross-linking for stability, while heat completes polymerization for final properties, achieving stability through controlled parameter transitions.
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 allows for the maintenance of steep via wall profiles and significantly reduces curing time, enhancing manufacturing throughput and preventing sidewall deformation, thus enabling the production of smaller, more compact semiconductor packages.
Implementation Method 1
cross-linking the polymer layer in a first process, after forming the via, by exposing the polymer layer to UV radiation to form a sidewall of the via with a sidewall slope at an angle greater than or equal to 45 degrees and to further form a cross-linked via sidewall surface
Implementation Method 2
thermally curing the polymer layer in a second process after the first process, wherein a maximum ramp-up rate from room temperature to a peak temperature of the second process is greater than 10 degrees Celsius per minute
Data Source
AI summary
A semiconductor device and method of making the semiconductor device is described. A semiconductor die can be provided. A polymer layer can be formed over the semiconductor die. A via can be formed in the polymer layer. The polymer layer can be cross-linked in a first process, after forming the via, by exposing the polymer layer to ultraviolet (UV) radiation to form a sidewall of the via with via sidewall slope greater than or equal to 45 degrees and to further form a cross-linked via sidewall surface. The polymer layer can be thermally cured in a second process after the first process, wherein a maximum ramp-up rate from room temperature to a peak temperature of the second process is greater than 10 degrees Celsius per minute.