I saw a picture of an ant carrying a micro chip,how do we make a microchip that small ?,essentially a computer

Question

I saw a picture of an ant carrying a micro chip,how do we make a microchip that small ?,essentially a computer

Answer 1

Some new advances are using X-ray lithography (I think that's what it's called).  This uses X-ray (which are smaller than light rays) to "print" or "draw" the circuits on the chip's "substrate".

But the chip is only a chip.  It needs other chips, and power, and input and output devices to make it useful.

So you won't find a full functioning computer that small -- only the chip.

Answer 2

We make tiny microchips by printing them.  We use special printers, kinda like an ink-jet printer, but instead of printing ink onto paper we print metal onto silicon.  Printers are constantly made with higher and higher resolution that are capable of making smaller and smaller metal connections on silicon.  I'm not sure if this is the same process for all chips but I know that some of the smallest ones are definitely printed.

Cool huh?

Answer 3

The picture (like all advertising) is fake (or misleading, you choose). However, the actual piece of silicon (called a die) inside most integrated circuits is tiny. The smaller ones are about .05 inches square or even smaller. Microcomputer chips (VLSI) are some what larger. There is some interest in wafer scale integration which would use an entire wafer as an ic.

There are two main process used to produce the circuit on silicon. Photo-lithography and Ion-implantation. Photo-lithography consists of taking each layer of the circuit (drawn by computers) and scaling it down to 1:1 proportions by photo-reduction, in the process multiplying the images. The wafer then is exposed through this  multiple image mask to a light source (having first been coated with photo-resist). It is also possible to use metal etched masks which improve the resolution. After exposure, the unexposed areas are developed (just like ordinary photos) which removes the unexposed area (positive resist acts differently). Then the wafer is processed in whichever way is required to produce the different layers.

The other method is ion-implantation. This uses computers via high energy beam machines to drive in ions directly into the crystal structure of the silicon. This method is very flexible but does not produce the depth of penetration that photo-lithography can. It also can produce defects if too much power is used.

Both processes are plagued by defects, brought about mostly by contamination of the silicon. This reduces the lifetime of ic's.

After fabrication, the wafer is first tested using probing machinery and computers, then sawed up, rejects are discarded then the good die are mounted inside the final package that you are familiar with. After connecting up all the connections on the die to the package pins, the package is closed and sealed then tested.