In the fields of semiconductor manufacturing and micro-nano processing, the electron beam lithography (EBL) machine, with its core advantages of nanometer-scale resolution and maskless direct writing, is known as the "nano-manufacturing engine that breaks through the diffraction limit of optics." As the "heart" of the electron beam lithography machine, the performance of the electron gun directly determines the equipment's ultimate resolution and processing efficiency. This article will take the ZEL304G electron beam lithography machine from ZEPTOOLS Technology as an example to deeply analyze the working principle and technological breakthroughs of the electron gun, revealing how it empowers high-end chip R&D and quantum device manufacturing.

I. Electron Gun: The "Energy Source" of Electron Beam Lithography Machines

The core principle of electron beam lithography is to use a focused electron beam to bombard a substrate coated with photoresist, changing the chemical properties of the photoresist (positive resist dissolution/negative resist crosslinking) to form the target micro-nano structure after development. The electron gun is the core component that generates and accelerates the electron beam; its function can be summarized as a "three-step process":

1. Electron Emission: The First Step from "Source" to "Beam"

The electron gun applies a high voltage of several kilovolts to the electron source (such as a field emission tip) through a high-voltage power supply, "pulling" electrons from the material surface (field emission mechanism) to form an initial electron cloud. ZEPTOOLS Technology's ZEL304G uses Schottky field emission electron gun By optimizing the material and geometric structure of the field emission tip, it achieves a lower threshold voltage and higher electron emission density, ensuring high brightness and stability of the electron beam.

2. Electron Acceleration: Giving Electrons the Ability to "Penetrate and Focus"

After being accelerated by the accelerating voltage (ZEL304G supports 20V~30kV continuous adjustment), the emitted electrons obtain extremely high kinetic energy (e.g., at 30kV accelerating voltage, the electron wavelength is only 0.0069nm). At the same time, the electron beam is focused by an electromagnetic lens system (such as a condenser lens, objective lens), compressing the diverging electron cloud into an "electron probe" with a diameter of only a few nanometers. The minimum spot size of ZEL304G ≤2nm benefits from the synergistic optimization of the electromagnetic lens and the field emission electron gun.

3. Electron Scanning: Precisely "Writing" Nano-patterns

The focused electron beam is controlled by deflection coils to perform point-by-point scanning or vector scanning on the sample surface (ZEL304G supports various modes such as sequential scanning, cyclic scanning, and spiral scanning), bombarding the photoresist according to the preset pattern. Its core advantage lies in "maskless direct writing"—no need to produce a physical mask, it can directly input graphic data through a computer, flexibly realizing the rapid processing of complex structures.

II. ZEPTOOLS Technology's Electron Gun Technological Breakthroughs: From "Usable" to "Leading"

Compared with traditional electron beam lithography machines, ZEPTOOLS Technology's ZEL304G electron gun has achieved three key breakthroughs in design, making it a benchmark for domestic high-end electron beam lithography equipment:

1. Balance of High Brightness and Low Divergence Angle

The brightness of the field emission electron gun (electron flow intensity per unit area, per unit solid angle) directly affects the focusing ability of the electron beam. ZEL304G optimizes the vacuum environment and emission mechanism of the field emission tip, improving the electron beam brightness to an industry-leading level, while controlling the energy divergence angle within a very small range (spot size ≤2nm), ensuring the uniformity and edge sharpness of the nanometer-level linewidth.

2. Combination of High Current Density and Long Lifespan

The current density of the electron beam determines the exposure efficiency—higher current density can deposit more energy in the same amount of time, improving processing speed. The electron gun beam current density of ZEL304G is >5300 A/cm², far exceeding conventional equipment. At the same time, through the fatigue-resistant design of the field emission tip (such as anti-ion bombardment coating), the lifespan is extended to thousands of hours, greatly reducing user maintenance costs.

3. High Degree of Synergy with the Entire System

The electron gun is not an isolated component; its performance needs to be deeply matched with systems such as the pattern generator and sample stage. The electron gun of ZEL304G seamlessly coordinates with the standard high-precision laser interferometer sample stage (travel ≤105mm) and high-performance FPGA pattern generator (maximum scanning speed 50MHz), supporting functions such as field calibration and multi-layer automatic exposure, easily completing high-precision processing from simple lines to complex three-dimensional structures.

III. Application Scenarios: An "All-around Player" from the Laboratory to Industrialization

The performance of the electron gun in ZEPTOOLS Technology's ZEL304G electron beam lithography machine shows irreplaceable advantages in the following fields:

Cutting-edge scientific research : In quantum chip manufacturing, the electron gun can precisely etch superconducting qubit arrays (linewidth ≤10nm); in two-dimensional material research, it supports integration with high dielectric constant media (such as CCTO films), promoting the development of high-performance two-dimensional devices. 
Semiconductor manufacturing : As a "mask manufacturing tool" for EUV lithography, ZEL304G can process nanometer-level phase-shift masks (accuracy up to 0.1nm), supporting the R&D of chips with processes below 3nm. 
Industrial micro-nano processing : In fields such as MEMS sensors and photonic integrated devices (such as nano-optical waveguides), the high resolution and high efficiency of the electron gun can meet the needs of small-batch, customized production.

Conclusion: The "Chinese Core" of the Electron Gun, Empowering the "Acceleration" of Nano-manufacturing

From laboratory prototypes to mass-produced industrial-grade equipment, the technological breakthroughs of the electron gun in ZEPTOOLS Technology's ZEL304G electron beam lithography machine mark China's transition from "following" to "running alongside" in the field of high-end electron beam lithography. With the advancement of research and development of next-generation technologies such as multi-beam parallel and hybrid lithography, ZEPTOOLS Technology's electron gun will continue to lead the innovation wave of nano-manufacturing, injecting strong impetus into the independent and controllable development of China's semiconductor industry.