Technology

Many integrated circuits are mostly fabricated using quite a number of materials from metals and alloys of metals. The alloys form a wide scope aluminum-copper alloy, titanium, tungsten, an alloy of aluminum and Titanium, which are all joined to the main frame of the silica matrix according to Gibilisco. Alloys have a higher ductile strength which makes them withstand thermal forces in the circuit. Other materials which are semiconductors can be used but silicon has found most application because its refractory quality. The microchips are therefore fabricated from wafers which mostly comprise pure silicon. Iron is the material that is used to make the core that is surrounded or rather wound using wire which is made from copper whereas the pins are made from Copper-Zinc alloy (Brass). Brass is better in this application because the pure metals of Copper and Zinc have a knee in their stress-strain curve as in the case with most metals. This knee could cause failure in the circuit. Moreover, brass has also good conductivity.

The integrated circuit has the first two layers which are made on a substrate of a semiconductor which is mainly silicon. The first layer is a made from a high k substance. Gibilisco(1992, pp. 33-51) says that a high k substance is a common term that denotes a material having a high dielectric constant when compared to normal dielectrics like the oxides of silicon or the corresponding nitride. Such high k materials form part of the oxides of the transitional elements in the periodic table. These include oxides of hafnium or zirconium or even ytterbium although it is hard to come by. The second layer consists of the nitride of Titanium. Simon and Cavette (1996, par. 1-21) states that the second layer also has a configuration of a conductive region which may or may not be a barrier of diffusion as a main function required in the layer.

Multiple layers
Gibilisco indicate that the layers that are applied to make part of the electrical connections existing in between the layers of chips are made of metal obviously because of high electrical properties of the metals. The last chip is put under cover which is mainly used for protection and has copper wires used to link the chip to the circuit board of the computer. Copper is needed here because it is a good conductor of electricity and will be most appropriate in the transfer of electrical impulses. The chips of integrated circuits are semiconductor elements which are fabricated from wafers of semiconductors where a polymer material is used for the process of bonding. This bonding material mostly used in the fabrication of an integrated circuit is Atactic polypropylene. The Atactic polypropylene polymer according to Gibilisco has a usual additive which could be an anti-oxidant or a stabilizer.  

Low strength and low young modulus of the Atactic polypropylene makes it mesh well in the silica matrix.  It is able to yield a uniform bond all through the surface of the substrate as well as forms bond which have a standard release temperatures. Moreover, the thermal cyclic through the ranges of temperature used in the process of transferring technique does not lead to a change of the characteristics of bonding neither does it change the release temperatures. In simple terms, Simon and Cavette (1996, par. 1-21) explain by saying that the characteristics of the polymer are not affected by the processes that occur in the integrated circuit. The lithography process, patterns are defined through the application of a liquid which is viscous (scientifically referred to as a photo resist liquid) on the surface of wafer. The photo resist taken through a process of baking for the purpose of hardening. The photo-resist is removed selectively through projection of light in a rectile having mask information. As a circuit, there are auxiliary support boards as well as link the electronic components through conductive ways which are etched using sheets of copper. These copper sheets are laminated on a substrate which is non-conductive.

The layers of conduction are made of metal foils of the copper element according to the description made by Simon and Cavette (1996, par. 1-21). This is because of the good properties of electricity conduction of copper. Copper is needed here to enhance the functioning of the integrated circuit through conduction of electrical impulses. The layers of insulation which are dielectric are specifically manufactured through a lamination process using the prepregnation of the epoxy resin. The epoxy resin is a composite material which enhances the insulation function required in the circuit. Epoxy has a high tensile strength which makes it applicable at high temperatures and therefore can withstand heat generated in the circuit. Simon and Cavette (1996, par. 1-21) indicates that the board aforementioned is particularly coated with a mask of solder material which has a green color. There are various dielectrics that could be opted for to make provision for diverse values of insulation which is wholly depended on the demands according to the given circuit. These dielectrics include such materials like Teflon scientifically known as polytetrafluoroethylene, CEM-1, FR-4, CEM-3 or FR-1.

Many printed integrated circuit boards are fabricated using a copper layer over the whole substrate surface as described by Simon and Cavette (1996, par. 1-21). A process called etching is used to remove excess copper that is not needed. This is done after applying a mask which is made of glass material. From this paper, it is clear that the Silicon element has taken a center stage in the fabrication of an integrated circuit. It is the backbone of the whole integrated circuit fabrication. Towards the conclusion of the paper, the advantages of silicon over the rest of the other material elements are as highlighted below.

Advantages of Silicon in the IC
Silicon has found a major application in the fabrication process of an integrated circuit due to its characteristics of making a semiconductor substrate which forms the matrix of the integrated circuit. Moreover, silicon is readily available and thus makes the entire process economically feasible. The inscribed part of giving identity in such delicate parts of the IC is made possible using silicon.

Generally silica matrix has high softening temperatures as the circuit will often generate a lot of heat. Silicon is able to resists forces and fatigue due to thermal expansion because of its quality of being high refractory. Moreover, it has high thermal stabilities and high tensile strength (stress-strain ratio) when the rest of the other materials are incorporated to its matrix in this application.