What Is the Dielectric Constant?

When an electric field is applied to the medium, the induced charges are generated and the electric field is weakened. The ratio of the original applied electric field (in vacuum) to the final electric field in the medium is the permittivity, also known as the induction rate, and is frequency-dependent. Dielectric constant is the product of relative dielectric constant and absolute dielectric constant in vacuum. If a material with a high dielectric constant is placed in an electric field, the strength of the electric field will decrease considerably in the dielectric. The relative permittivity of an ideal conductor is infinite.

Attached to the relative dielectric constant of common solvents, the test frequency is 1KHz at room temperature.

gas		Relative permittivity	solid		Relative permittivity
steam Gaseous bromine helium hydrogen oxygen nitrogen Argon Gaseous mercury air Hydrogen sulfide vacuum Diethyl ether Liquid carbon dioxide Methanol Ethanol water Liquid ammonia Liquid helium Liquid hydrogen Liquid oxygen Liquid nitrogen Liquid chlorine kerosene turpentine benzene paint glycerin		1.00785 1.0128 1.000074 1.000264 1.00051 1.00058 1.00056 1.00074 1.000585 1.004 1 4.335 1.585 33.7 25.7 81.5 16.2 1.058 1.22 1.465 2.28 1.9 2 4 2.2 2.283 3.5 45.8	Solid ammonia solid acetic acid paraffin Polystyrene Radio Porcelain UHF porcelain Barium dioxide rubber Hard rubber paper Dry sand 15% water wet sand (diamond) wood amber ice Shellac (Shell) celluloid glass Yellow phosphorus sulfur carbon Mica granite marble salt Beryllium oxide PVC		4.01 4.1 2.0 2.3 2.4 2.6 6 6.5 7 8.5 106 2 3 4.3 2.5 2.5 About 2 to 8 2.8 2.8 3 4 3.3 4 11 5 ~ 10 4.2 5.5 16.5 6 8 6 ~ 8 8.3 6.2 7.5 9 3.1 ~ 3.5

Explanation of "dielectric constant" in the reference book:

1. Also known as permittivity or

In the past ten years, the research on low dielectric constant materials in the semiconductor industry has been increasing, and the types of materials have also varied. However, these low dielectric constant materials can be applied in integrated circuit production processes much faster than people think. Its main

Measurement results of mechanical properties of low dielectric constant films

The reason is that many low dielectric constant materials cannot meet the requirements of integrated circuit process applications. Figure 2 is the forecast of the application of low dielectric constant materials in integrated circuit technology by the semiconductor industry in different periods.

As early as 1997, it was thought that in 2003, the dielectric constant (k value) of the insulating material to be used in integrated circuit technology would reach 1.5. Over time, however, this optimistic estimate has been continuously updated. By 2003, the International Semiconductor Technology Plan (ITRS 2003 [7]) gave the application of low dielectric constant materials in integrated circuits in the next few years, and its dielectric constant range has become 2.7 ~ 3.1.

The reason why people s predictions are so different from reality is that in integrated circuit technology, low dielectric constant materials must meet many conditions, such as: sufficient mechanical strength to support the structure of multi-layer wiring, Gao Yang Young's modulus, high breakdown voltage (4MV / cm), low leakage current (10-9 at 1MV / cm), high thermal stability (thermal stability> 450oC), good adhesive strength (Adhesion strength), low moisture uptake, low film stress, high planarization, low coefficient of thermal expansion, and compatibility with chemical mechanical polishing processes ( compatibility with CMP process) and more. A low-dielectric-constant material capable of satisfying the above-mentioned characteristics is not easily obtained. For example, the dielectric constant and thermal conductivity of a thin film tend to be inversely related. Therefore, the characteristics of the low dielectric constant material itself directly affect the difficulty of process integration.

Among the VLSI manufacturers, many companies such as TSMC, Motorola, AMD, and NEC have selected Applied Materials' Black Diamond as a low-dielectric constant material in order to develop 90nm and below technologies. This material uses PE-CVD technology [8], which is fully integrated with the existing integrated circuit production process, and the BLOk film is introduced as the isolation layer between the low dielectric constant material and the metal, which solves many of the problems mentioned above. It is one of the few low dielectric constant materials that has been used in the commercial production of integrated circuits. ^[2]