Silicon Materials Exist Way in Our Society

The last decades have seen an ever-increasing use of silicon materials for semiconductor . Silicon properties Beside its electronic properties the growing demand of silicon is due to

its outstanding mechanical,chemical and thermal properties.

It is almost an ideal structural material. It has about the same Young’s modulus as steel, but is as

light as aluminum. Besides, It has a thermal conductivity comparable to metals. Its thermal expansion

coefficient is low compared to most metals, making it insensitive to thermal

shock and fatigue. Or It is pretty inert in a normal environments, it does not react with most

acidic compounds, but it reacts with dilute halogens. Or Due to its crystallography, both isotropic and chemical etching can be employed to create micro structures

in a controlled fashion. Or Its electric conductivity can be tuned by adding small

amounts of impurities

Now we would like to introduce some information about the silicon materials as single wafer in

MEMS. Silicon in MEMS Single crystal silicon is the most used semiconductor material in

MEMS manufacturing and electronic circuits industry. Being the second most abundant

element on earth, silicon is a relatively inexpensive material and is highly reliable

because of its properties; its processing can be readily controlled to obtain high level of

precision and reproduction and lots of micro machined devices can be made from a single

wafe. The processing of Silicon wafers to produce integrated circuits involves a good deal of chemistry

and physics. In order to alter the surface conditions and properties, it is necessary to use both

inert and toxic chemicals, specific and unusual conditions, and to manipulate those conditions

with both plasma-state elements and with RF (Radio Frequency) energies. Starting with thin, round wafers of silicon crystal, in diameters of 150, 200, and 300mm, the processes described

here build up a succession of layers of materials and geometries to produce thousands of

electronic devices at tiny sizes, which together function as integrated circuits (ICs). The devices

which now occupy the surface of a one-inch square IC would have occupied the better part of a

medium-sized room 20 years ago, when all these devices (transistors, resistors, capacitors, and so

on) were only available as discreet units. The conditions under which these processes can work to successfully transform the silicon into

ICs require an absolute absence of contaminants. Thus, the process chambers normally operate

under vacuum, with elemental, molecular, and other particulate contaminants rigorously

controlled. In order to understand these processes, then, we will begin the study of

semiconductor processing with an overview of vacuum systems and theory, of gas systems and

theory, as applied specifically to these tools, and of clean room processes and procedures The

semiconductor industry reflects and serves an extraordinary revolution in both materials science

and in data processing and storage. As recently as 1980, most individuals had no idea that

computers would ever impact their personal lives. Today, many families own one or two

computers, and use many other computers and dedicated processor systems in their appliances

and automobiles. Today, only twenty years later, we are continually pushing the envelope of

capabilities of the data processing and storage systems that are now in the mainstream. Ingenuity

and creativity, along with great strides in quality control, process control, and worker productivity, are leading daily to new ideas about how to further reduce device size and data density. On the

horizon are visions of biochemically based devices which will be far smaller, work faster, and

generate less heat than current devices. It is worth spending some time imagining where this

evolving technology will take us, and the society we live in.

In my opinion ,the silicon materials as many kinds of exact way in our daily life .