1、 Physical law limitation
The core of microelectronic technology lies in the manufacturing of integrated circuit chips. Combined with the development process of microelectronic technology, the development of advanced microelectronic technology is constantly breaking through the integration number of single chip components of integrated circuit. Nowadays, nearly 500 million electronic components can be integrated on a single chip, which has exceeded the limit of super large integration scale, However, from the perspective of physical law, the development of microelectronic technology is still subject to its own objective limitations. In practical applications, the IC performance can usually be improved by reducing the size of electronic components, but the reduction of characteristic size during electronic components also means that the thickness of oxide layer and channel length are also reduced, which makes it more difficult to overcome the "through effect" of components. For example, when the quantum tunnel penetration effect increases, the static power consumption of electronic components will increase. When the proportion of static power consumption reaches a certain limit value of the total power consumption of the circuit, it indicates that this state is the limit value of transistor reduction, but in terms of today's scientific and technological level, it is still unable to jump out of the limitations of physical laws.
2、 Material limitation
Silicon crystal is commonly used in microelectronic technology. Due to its own characteristics, this material hinders the progress of microelectronic technology to a certain extent. Nowadays, researchers begin to gradually replace the commonly used silicon crystal materials with oxide semiconductor materials and superconductor materials. In addition, transistors made of carbon nanotubes provide new ideas for the innovation of microelectronic technology. After experimental research, scholars concluded that the total output signal in the new nanotube circuit is greater than the input signal. The conclusion also shows that the nanotube circuit has a certain amplification function. At present, some scholars have proposed to use plastic semiconductor technology to prepare integrated circuits that are not easy to crack, which also provides a new direction for the development of microelectronic technology.
3、 Process technical limitations
1. Lithography equipment scale problem. The most critical equipment in the microelectronic technology process is the lithography machine (exposure tool). The manufacturing process of this equipment is complex, the cost is high and its precision requirements are high. The equipment resolution and focal depth will affect the application of lithography technology. When the size is promoted to 0.05um and stagnates for a long time, the integrated circuit will not be able to quickly enter the nano era.
2. Interconnect lead problems. If the area on the integrated circuit board is too small or the number of transistors per unit area increases, the cross-sectional area between interconnection lines will be reduced and the resistance will be increased, resulting in the increase of the overall circuit = reaction time. On the other hand, although the reduction of the size of the integrated circuit board can improve the working efficiency of transistors, it will increase the reflection time of interconnection leads. Therefore, How to optimize the interconnection leads under the condition of existing integration scale is a key topic studied by many experts and scholars.
3. Reliability issues. As mentioned above, integrated circuits are gradually developing towards fine processing and small-scale components, but the use of small-scale components will improve the operation efficiency of the whole circuit system, but reduce the service life of electronic components. Especially in the manufacturing process, the reliability problem seriously affects the development of microelectronic technology.
4. Heat dissipation problem. The problem of heat dissipation in the application of microelectronic technology is mainly determined by the level of packaging technology. Nowadays, with the development of integration towards super scale, the integration function will inevitably become more and more complex in the future. Therefore, when designing, it is necessary to measure the total power consumption of the whole circuit and the relationship between packaging technologies.
