Plasma is an ionized gas with high energy and the ability to interact with various substances, ionized to such an extent that the electric forces of attraction between differently charged particles are balanced in it by the repulsive forces between similarly charged particles. Regardless of the gas density and its degree of ionization, the plasma gas volume remains electrically neutral.

 

According to the physical and chemical mechanism of interaction between the solid surface and plasma particles, all processes of "dry" etching can be conditionally divided into three groups.

 

• Ion etching
• Plasma (plasma-chemical) etching
• Reactive ion and ion-chemical etching
   

The group of plasma (plasma-chemical) etching processes by its mechanism of influence on the surface is opposite to the processes of purely ionic etching. Here we deal with processes based on purely chemical interaction of surface layers of material with chemically active particles generated in plasma, accompanied by the formation of volatile reaction products, their desorption and removal from the process zone. In this case, the plasma plays the role of a generator of chemically active particles. These particles are formed as a result of low-energy electron and ion bombardment, as well as radiation.

 

Let us also note two possible cases of plasma etching, leading to the presence of its two varieties. If the surface to be etched is in contact with plasma, then we are dealing directly with plasma chemical etching. In this case, the influence of electrons, radiation, and particles bombarding the surface, which are not directly involved in the etching process, cannot be discounted.

 

In the case of separation of the reaction space and the volume in which chemically active particles are generated, we deal with radical etching. In this process, separation, extraction from the discharge of radicals and free atoms takes place. Radical etching proceeds intensively without stimulation by radiation or bombardment with electrons or ions, this process often proceeds spontaneously.

Plasma chemistry technology is an innovative approach to processing various materials using plasma.

 

The basic idea of plasma chemistry is to use plasma to change the properties of materials or to produce new materials with unique characteristics. This technology can be applied in various industries such as electronics, medicine, energy, metallurgy and others.

 

One of the main advantages of plasma chemistry is the ability to process materials at low temperatures, which avoids their deformation or destruction. Also, plasma can be used to clean surfaces from contaminants, as well as to create thin films on various materials.

Plasma chemistry can also be used to solve environmental problems. For example, it can be used to clean water from contaminants or to dispose of hazardous waste. This reduces the negative impact on the environment and makes processes more efficient.

 

Plasma technologies include a set of methods for depositing thin and ultrathin layers on a semiconductor substrate, as well as a set of methods for dimensional etching of such layers with specified etching parameters. If we consider the methods of dimensional etching using dry technologies, we should always take into account that the whole range of such methods is wide.

 

Some methods, such as radical and plasma chemical etching, involve a mild, purely chemical interaction of the plasma medium with the substrate material, resulting in the formation of a volatile etching product and its removal (evacuation) from the plasma volume.

Another group of "dry" techniques includes methods of purely physical impact of high-energy plasma particles on the material surface and removal of atoms from the surface only as a result of material atomization. These are methods of ion etching, ion-beam, ion-chemical, where the physical factor is predominant.

But the most interesting and promising are the range of methods that combine the advantages of soft chemical action on the material with simultaneous physical atomization of the surface. Such methods include reactive ion-plasma etching, which allows controlling the contribution of physical and chemical factors.

 

In the field of modern microelectronics, the problem of precise removal of organic materials during the production of monolithic integrated circuits is still relevant. For this purpose, polymer films are used as photoresist, protective coatings and planarizing layers before applying metal and dielectric films. It is also important to clean the substrate surface of organic contaminants before applying any films. Liquid chemical reagents such as monoethanolamine, dimethylformamide and isopropyl alcohol are used for this purpose.

 

However, plasma chemical etching (PCT) is now gaining popularity, as it is highly accurate and fast, requires no additional surface cleaning, and can be used to treat a variety of materials. PCT is also a more environmentally friendly method and can be computer controlled.

In this process, samples are placed in a gas-discharge plasma that is activated by a high-frequency field. Plasma processes that can cause damage to the structure require careful investigation and selection of optimal parameters. Exposure of the polymer surface to plasma can change its contact properties and also improve its adhesion properties due to the formation of hydrophilic groups. These groups depend on the properties of the plasma and the nature of the gas used for its creation.

 

An important parameter is the discharge power, which affects the density of radicals and ions, as well as the ion energy. Increasing the power can accelerate the etching process, but at high values can lead to surface damage and degradation of the MIS. The discharge frequency and chamber pressure are also important because they affect the energy distribution of electrons and ions in the plasma. Low pressure and low frequency can increase the flux intensity and ion energy, which can affect the etch rate, selectivity, anisotropy and surface morphology.

 

Substrate temperature also plays a role in the etching process, as increasing it can accelerate chemical etching and reduce anisotropy.

 

When selecting a masking layer material for anisotropic etching of organic films, its compatibility with working gases and other MIS manufacturing operations must be considered. Aluminum is the optimal material for this purpose.

 

However, the optimal values of technological parameters may differ depending on the design features of the equipment. The study of the influence of processing parameters on the speed and anisotropy of the plasma chemical etching process can be useful in the production of MIS from various materials. The dependence of the quality of plasma chemical etching of GaAs substrates on the processing modes has been established, which may help to choose the optimal parameters to improve the adhesion of metallic and dielectric films. The dependence of the etching rate dependence of different grades of photoresists on the main process parameters was also found, which can help to choose the optimal processing mode for the removal of photoresist residues. Knowledge of the dependence of the etching rate dependence of polyimide and undermask etch rate on process parameters can be useful in the development of process routes for the production of MIS.

Plasma technologies in microelectronics play a key role in the production of semiconductor devices such as microchips, transistors and other components. They enable precise and controlled processing of materials at the microscopic level.
One of the major applications is the process of depositing thin films on the surface of semiconductor materials. Plasma is used to deposit various materials such as silicon, oxides, nitrides and others onto the chip surface. This can create protective layers, improve the electrical properties of the material, or add functional characteristics.

 

Another important application of plasma technology is the process of eceffect, or ecelithography. This process is used to create microchips and other microstructures on the surface of semiconductor materials. A plasma containing ions and electrons is directed at the surface of the material, causing it to erode or change its properties. This process makes it possible to create microcells with high precision and resolution.

Plasma technologies are also used to clean the surfaces of semiconductor materials from contaminants and residues. Plasma containing active particles interacts with contaminants and removes them from the surface. This is an important step in the manufacturing of semiconductor devices, as even the slightest contaminants can negatively affect their performance.

Plasma technology also finds application in the process of etching materials. Plasma can be used to remove layers of material from a surface or to create micro-reliefs and microstructures. This allows for the creation of more complex and functional devices.

In general, plasma technologies in microelectronics play an important role in the production of semiconductor devices. They enable precise material processing at the microscopic level, the creation of thin films, surface cleaning and the creation of complex microstructures. Thanks to plasma technology, we can produce better and more functional semiconductor devices, which contributes to the development of modern electronics.

 

Plasma chemistry technology continues to evolve and its potential has not yet been fully explored. It opens up new possibilities for creating innovative materials and solving complex problems in various fields. Through plasma chemistry, we can produce better products, improve production processes and contribute to sustainable development.