Cold Ion Source Chip for Direct Write Lithography
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor manufacturing processes face challenges in achieving precise edge definition and feature size reduction due to light diffraction issues with photolithography, leading to increased costs and complexity with multiple masks and steppers, and existing alternatives like EUV and e-beam lithography have inefficiencies and damage risks.
Innovation Solution
A Direct Write On Wafer (DWOW) printing system employing a micro-collimated proton accelerator with an ionjet head assembly and miniature proton accelerators, capable of selectively irradiating individual spots with high precision and energy control, allowing for direct writing on a 300 mm diameter wafer in one minute.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If feature size is reduced to increase transistor density, then productivity is improved, but device complexity increases due to multiple masks and steppers being required
Solution Approach 1:
The patent replaces the complex multi-mask photolithography system with a direct-write ion beam system. Instead of using multiple steppers and masks to achieve fine features, a single ion beam writing system directly creates the desired patterns. This substitution dramatically reduces the number of process steps and equipment needed.
Solution Approach 2:
The invention segments the lithography process into individual writable features that can be addressed independently by the ion beam. The system can selectively write to specific locations on the wafer, enabling complex patterns to be built up through sequential writing of individual features or lines, rather than requiring multiple global exposure steps.
2Manufacturing precision
If multiple masks and steppers are used to reduce feature size, then manufacturing precision is improved, but loss of time increases due to multiple exposure steps
Solution Approach 1:
The patent replaces sequential multi-step photolithography with parallel-capable direct-write ion beam lithography. The ion beam system can rapidly reposition and write different features, and multiple ion beams can operate simultaneously on different parts of the wafer, reducing the total cycle time while maintaining or improving precision.
Solution Approach 2:
The system performs preliminary positioning and focusing of the ion beam to the exact write location before each exposure event. This preliminary action ensures that each written feature achieves the desired precision without requiring subsequent correction steps or additional masks, reducing overall process time.
3Quantity of substance
If conventional ion sources are used, then ion production is achieved, but manufacturing precision deteriorates due to large lateral momentum of hot ions
Solution Approach 1:
The patent fundamentally changes the temperature parameter of the ion source, transitioning from hot ion sources (with ion temperatures in the eV to keV range) to cold ion sources (with ion temperatures below 1 eV). This parameter change dramatically reduces the lateral momentum spread of the ions, improving beam collimation and enabling sub-10 nm spot sizes while maintaining high ion production rates.
Solution Approach 2:
The invention creates a localized cold region at the ion extraction point using a cryogenically cooled ion source. This local quality change ensures that ions are produced with minimal thermal energy and narrow angular spread, while still allowing for sufficient ion production. The cold region is confined to the ion source area, with the ion beam being accelerated and focused downstream.
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 DWOW system achieves high-resolution lithography with precise spot sizes of 5 nm and efficient use of photoresists, reducing the need for multiple masks and steppers, thereby lowering costs and improving manufacturing throughput while minimizing wafer damage.
Implementation Method 1
The ion source produces cold ions that have an energy less than 30 eV and that have only a small amount of lateral momentum
Implementation Method 2
Each channel is an individually gated acceleration channel that is formed in a solid dielectric material. Ions are accelerated down the acceleration channel
Implementation Method 3
The micro-collimator has a plurality of channels. The length-to-width ratio of each channel is greater than five, and the channel width is less than one micron
Implementation Method 4
The DWOW system achieves high-resolution lithography with precise spot sizes of 5 nm and efficient use of photoresists
Implementation Method 5
The virtual image is written onto the wafer by successively writing lines of spots as the wafer is moved back and forth with respect to the ionjet head assembly
Data Source
AI summary
An assembly includes a cold ion source and a chip. The cold ion source is fixed to the chip so that ions from the ion source can enter an acceleration channel in the chip. In one specific example, the ion source includes an ion exchange membrane that produces cold ions in that the ions as produced have an energy of less than 30 eV. The chip includes a substrate (such as a semiconductor substrate or a glass substrate) and a dielectric layer disposed on substrate, where the acceleration channel is a channel formed into the dielectric layer. In one specific example, the assembly is part of a Direct Write On Wafer (DWOW) printing system. The DWOW printing system is useful in semiconductor processing in that it can direct write an image onto a 300 mm diameter wafer in one minute.