USE OF THICK LAYERS OF POROUS ANODIC SILICON OXIDE FOR VARICAP MANUFACTURING TECHNOLOGY

Abstract

Varicaps or diodes with variable capacitance are one of the most important elements of electronic technology. They are used in modern electronic equipment for various purposes, for example, in communication equipment and automatic control equipment for tuning to the required frequency. Due to the need to develop new equipment, the requirements for the parameters and characteristics of electronic components that are used in this equipment are constantly increasing, including and up to varicaps. Therefore, the manufacture of varicaps with modern requirements to a set of parameters and characteristics is an urgent task. Various requirements are imposed on the parameters and characteristics of varicaps: breakdown voltage, quality factor, capacitance overlap coefficient, capacitance value and the level of reverse currents. Obtaining a set of varicap parameters with modern requirements for each parameter is a rather difficult task. For example, with an increase in the breakdown voltage, the quality factor varicap decreases. Additional requirements for the manufacturing technology of varicaps are the requirements for the repeatability of parameters and characteristics and the requirements for the cost of production. To reduce the cost of production, it is necessary to reduce the number of technological operations, primarily the number of photolithography operations. And the use of methods of self-alignment of technological layers leads both to a decrease in the number of photolithography operations and to an improvement in the repeatability of the parameters and characteristics of the product. Varicaps are manufactured using various technologies, depending on the requirements for the main characteristics (breakdown voltage or quality factor, or capacitance overlap coefficient). Each design or technology has its advantages and disadvantages. However, there is still no such technology that would allow you to create devices with the best combination of all parameters and characteristics at a low manufacturing cost. The aim of the work is to create technological process for the manufacture of varicaps, which allows you to obtain all the parameters and characteristics of devices with modern requirements for them at a minimum manufacturing cost.