Offset Reticle with Open Feature for Implant Mask Removal
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Solution Overview
Problem
Current photolithography systems face challenges in efficiently removing ion implant masks, particularly due to the formation of undesirable Teflon-like materials and the time-consuming process of removing the crust layer, which complicates the subsequent cleaning and etching processes.
Innovation Solution
A novel reticle design with an offset arrangement of exposure patterns and an open feature allows for the exposure and efficient removal of photoresist material above incomplete dies during the photolithography process, reducing the need for extensive plasma ashing and wet etching, thereby simplifying the removal of the implant mask and minimizing particle formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional photolithography systems are used to form implant mask layers, then the mask layer can be formed with standard processes, but the removal of the mask layer becomes time-consuming and complex due to crust layer formation and Teflon-like material deposition
Solution Approach 1:
The reticle is designed with an open feature that exposes portions of the substrate before the implant mask is fully formed. This preliminary exposure creates a patterned photoresist structure that prevents uniform crust layer formation during ion implantation, making subsequent mask removal easier and faster without requiring extensive plasma ashing or wet etching
2Object-generated harmful factors
If standard implant mask removal processes are used, then the mask can be removed, but undesirable Teflon-like materials are formed and particle formation increases
Solution Approach 1:
The reticle design segments the exposure area into patterned regions (through the arrangement of exposure patterns) and open regions (through the open feature). This segmentation causes the photoresist to be exposed differently in various areas, preventing uniform Teflon-like material deposition and reducing particle formation during mask removal
3Quantity of substance
If complete photoresist material is retained during ion implantation, then the implant mask provides full coverage, but extensive plasma ashing and wet etching are required for removal
Solution Approach 1:
The open feature in the reticle design extracts or removes the need for complete photoresist material coverage in certain areas. By intentionally leaving open portions exposed before implantation, the design eliminates the need for extensive plasma ashing and wet etching processes that would otherwise be required to remove complete photoresist masks
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 enables easier and more efficient removal of the implant mask, reducing the likelihood of particle formation and improving processing efficiency by allowing significant portions of undesirable photoresist material to be removed during the exposure/development process, thus streamlining the ion implantation process.
Implementation Method 1
a reticle that is adapted for use in exposing photoresist during a photolithography exposure process
Data Source
AI summary
In one example, a reticle disclosed herein includes a body having a center, an arrangement of a plurality of exposure patterns, wherein a center of the arrangement is offset from the center of the body, and at least one open feature defined on or through the body of the reticle. In another example, a method is disclosed that includes forming a layer of photoresist above a plurality of functional die and a plurality of incomplete die, exposing the photoresist material positioned above at least one of the functional die and/or at least one of the incomplete die, performing an incomplete die exposure processes via an open feature of the reticle to expose substantially all of the photoresist material positioned above the plurality of incomplete die, and developing the photoresist to remove the portions of the photoresist material positioned above the incomplete die.