The so-called electromigration problem refers to that when a large number of electrons flow through a section of conductor, the atoms of the conductor material leave their original positions due to the impact of electrons, leaving vacancies. Too many vacancies will lead to the disconnection of wires, while atoms leaving the original position will stay in other positions, causing short circuits in other places, thus affecting the logic function of the chip and further causing the chip to be unusable. This is why many Northwood Pentium 4 have been replaced by SNDS (Northwood Outbreak Syndrome). When enthusiasts overclocked Northwood Pentium 4 for the first time, they were eager for success and greatly increased the chip voltage. Serious electromigration problems caused the chip to be paralyzed. This is Intel's first attempt at copper interconnection technology, and obviously some improvements are needed. On the other hand, the application of copper interconnection technology can reduce the chip area, and at the same time, because the resistance of copper conductor is lower, the current passing through it is faster.
In addition to these two main materials, some kinds of chemical raw materials are needed in the design process of the chip, which play different roles, so I won't go into details here. In the preparation stage of chip manufacturing, after the collection of basic raw materials is completed, some of these raw materials need to be pretreated. As the most important raw material, the treatment of silicon is very important. First of all, silicon raw materials should be chemically purified to reach the level of raw materials used in semiconductor industry. In order to make these silicon raw materials meet the processing needs of integrated circuit manufacturing, they must be shaped. This step is completed by melting silicon raw materials and then injecting liquid silicon into a large high-temperature time-sensitive container.