Toward 100 Mega-frames per second: design of an ultimate ultra-high-speed image sensor

Area of Science:

• * Advanced semiconductor device physics
• * High-speed imaging technology
• * Image sensor design

Background:

• * Ultra-high frame rates are crucial for scientific and industrial applications.
• * Existing image sensors face limitations in achieving theoretical maximum frame rates.
• * Signal electron transit time is a critical bottleneck in high-speed imaging.

Purpose of the Study:

• * To summarize the design of an ultra-high speed image sensor.
• * To identify and overcome critical factors limiting frame rates.
• * To achieve a theoretical maximum frame rate of 100 Mega-frames per second (Mfps).

Main Methods:

• * Design of a backside illuminated in situ storage image sensor (BSI ISIS).
• * Transient simulation to estimate theoretical maximum frame rate.
• * Implementation of a special p-well design for reduced electron transit time.
• * RC delay reduction using an extra metal layer for electrodes.
• * Inductance minimization technique with stacked differential bus lines.

Main Results:

• * Theoretical maximum frame rate estimated at 100 Mfps.
• * Achieved significantly shorter electron transit time through optimized p-well design.
• * Reduced RC delay and minimized on-chip inductance for faster signal propagation.
• * Sensor features 140,800 pixels with 126 linear storage elements per pixel.

Conclusions:

• * The BSI ISIS structure is effective for achieving ultra-high frame rates.
• * Optimized p-well design and reduced parasitic effects are key to high-speed performance.
• * The developed technologies enable image sensors to approach theoretical speed limits.