Electrical Power - Assignment Example

Literature Search: Wafer Yield Maximisation in Semiconductor Chips ProductionIntroductionThe process of creating semiconductor integrated circuits usually involves some intricate trade-offs to attain a balanced and uniform coating around the chips. When designing semiconductor chips such as microprocessors and control chips, the design engineers often seek to attain a maximum wafer yield. They would try to get uniform thickness for the chips they produce in the manufacturing process. Wafers are normally used to produce these semiconductor chips, and there is a certain proportion of the chips that are deemed appropriate and acceptable for use in designing electrical components.

This acceptable proportion is what is referred to as wafer yield.Producing semiconductor chips with uniform thickness is normally a challenge to the engineers, since several factors influence the thickness outcome. The three main factors (variables) that determine the outcome of the semi-conductor thickness include speed, distance and pressure factors applicable on the chemical mechanical planarization machine used.Semiconductor building processThe first step in a building a semiconductor chip is to design the circuit for the chip.

Next, the designer should build a mask through a manufacturing process. The mask should be based on the design of the circuit pattern. Thirdly, a wafer should be manufactured to provide a base for the chip. Such wafers may be made using materials like silicon. In the fourth stage, the mask and the wafer are then used to form the circuit. The circuit is etched on the wafer (pre-process). After that, the post-process involves the assembly of the wafer into a semiconductor chip. This is done after it passes the pre-process stage.

The activities done in this stage include assembly through bonding and dicing, and packaging of the chip by sealing (Gleason, Tobin Jr, Karnowski, and Lakhani, 1998, p.237). The complete semiconductor chip may then be inspected to ascertain operability and durability. The surface of the wafer is normally oxidised. Thereafter, the wafer surface is insulated with a film using the CVD process. Other important processes include vapour deposition used to build electrodes on the wafer, ion implantation process, and the resist process used to add photosensitive materials.

The circuit pattern is printed to the wafer from the mask through an exposure process. It is important to form the circuit patterns in a superposed manner on the wafer (Luo and Dornfeld, 2003, p.17). Therefore, the etching process serves a function of removing any portions lying outside the desired circuit image (resist image). Role of High Resolution projection in Manufacturing ProcessThe semiconductor chips are normally made using precise illumination guided by sophisticated and accurate detection systems.

Such illumination often emanates from a projection exposure apparatus known as a stepper. It is then directed to the surface of the wafer during the manufacture of semiconductor devices. The miniaturization process of semiconductor chips is an intricate process that entails a TTL autofocusing function to change the focus angle at extremely low scales that fit the wafers being worked on. VLSI and LSI semiconductor chips require high-resolution projection in order to suffice most of the circuits etched on the wafers.

High resolution would allow the intersection of the wafer surface with the focal plane of the beam. The focus position of the projection exposure apparatus must first be determined with great precision. This would be the reference point for the automated focus detection system. In cases where the design engineer seeks to alter the thickness of the thickness of the wafer coating, this reference point is used to determine an optimum position for printing the wafer. Some of the factors considered at this stage include the desired wafer coating thickness.

Another considerable factor is whether the wafer has a stepped structure with a predetermined thickness or not.