Inductively Coupled Plasma Etching (ICP)
In ICP etching equipment, the induction coil is generally located above or around the reaction chamber. When RF current passes through the coil, a periodically changing magnetic field is generated. According to Faraday's law of electromagnetic induction, a changing magnetic field will induce a circular electric field inside the cavity. This electric field accelerates the movement of electrons, causing them to collide with gas molecules and ionize them, producing a large number of active particles such as ions, electrons, and free radicals, forming a high-density plasma. In this process, the energy distribution and motion trajectory of electrons play a crucial role in the generation and maintenance of plasma. In addition, by adjusting parameters such as frequency, power, and coil turns of the RF power supply, the density and characteristics of the plasma can be effectively controlled.
1. Technical advantages
The high etching rate is significantly improved compared to traditional methods such as CCP etching, as it can generate high-density plasma and provide a large number of active particles to participate in the etching reaction. This is of great significance for improving production efficiency and shortening manufacturing cycles in large-scale integrated circuit manufacturing.
Good etching uniformity can precisely control the distribution of plasma and ion energy, enabling a more uniform etching effect on large-area substrates. This is crucial for ensuring consistency and performance stability of various devices during the chip manufacturing process.
The high aspect ratio etching capability can achieve precise etching of high aspect ratio structures, such as preparing nanoscale vertical vias and fine gate structures in advanced semiconductor manufacturing processes. Its independent control of plasma density and ion energy characteristics helps to avoid the problem of insufficient bottom etching or excessive sidewall etching when etching high aspect ratio structures.
2. Technical limitations: High equipment costs and high requirements for gas purity.
3. Key points of process control: gas flow rate and ratio, RF power regulation.
4. Application expansion: Third generation semiconductor manufacturing, optoelectronic device manufacturing.
CCP Etching (Capacitive Coupled Plasma Etching)
In the CCP etching system, the distance, area, and parameters of the RF power source (such as frequency and power) between two parallel electrode plates have a significant impact on the generation and characteristics of the plasma. When radio frequency voltage is applied to the electrode, electrons accelerate in the electric field and collide with gas molecules to produce ionization. Due to the small mass of electrons, their movement speed is much faster than that of ions, and a sheath layer will form on the electrode surface. The presence of the sheath layer can affect the trajectory and energy distribution of ions, thereby affecting the etching process. In addition, the electric field distribution in CCP etching is relatively uniform, which makes the plasma have relatively uniform characteristics to a certain extent.
1. Technical advantages
Compared with ICP etching equipment, CCP etching equipment has a relatively simple structure and no complex inductive coupling system. This makes the installation, debugging, and daily maintenance of the equipment more convenient, reducing the maintenance cost and technical threshold of the equipment.
For some simple etching processes or applications that do not require particularly high etching accuracy, CCP etching can quickly achieve different etching effects by adjusting parameters such as RF power, gas type, and flow rate. Its flexibility gives it certain advantages in some small-scale production or research and development stages.
2. Technical limitations: Low etching rate and limited etching accuracy.
3. Key points of process control: electrode spacing adjustment, RF frequency selection.
4. Application expansion: Printed circuit board (PCB) manufacturing, preliminary processing of micro and nano structures.

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