CMOS compatible 2T pixel for on-wafer in-situ EUV detection

Area of Science:

• Semiconductor Physics
• Optoelectronics
• Advanced Materials

Background:

• Extreme Ultraviolet (EUV) lithography requires precise in-situ monitoring of light distribution.
• Existing EUV detection methods often lack the resolution, stability, or CMOS compatibility needed for on-wafer applications.

Purpose of the Study:

• To propose and demonstrate a novel 2-transistor (2T) pixel detector for EUV applications.
• To achieve high spectral range, spatial resolution, and CMOS compatibility in an EUV detector.
• To enable on-wafer 2D EUV flux distribution recording without external power.

Main Methods:

• Development of a novel 2T pixel using advanced CMOS technology.
• Investigation of the EUV-induced discharging mechanism through a proper initialization process.
• Establishment of an EUV-induced electron emission efficiency model.
• Fabrication and testing of a 2D array of 2T EUV detector pixels.

Main Results:

• The proposed 2T EUV detector demonstrates a high spectral range (< 267 nm) and spatial resolution (67 μm).
• The detector exhibits high stability and seamless CMOS compatibility.
• On-wafer recording of 2D EUV flux distribution was achieved without external power.
• An EUV-induced electron emission efficiency model was successfully established.

Conclusions:

• The novel 2T EUV detector is a viable solution for high-resolution, in-situ EUV flux monitoring.
• The demonstrated 2D array accurately reflects projected patterns on chip/wafer surfaces.
• This technology advances the capabilities for process control in EUV lithography.