Why are semiconductors so critical and useful in building computers?
First off, let's revise what a semiconductor actually is. A semiconductor (such as silicon, germanium and gallium arsenide) have conductivity in between a good conductor (metal such as copper) and an insulator (think of it as a mean value theorem type result applied to electrical conductivity). Why is that useful? To understand this, contemplate the following ditty praising the usefulness of semiconductors:
"Black and White are Boolean True,
But semiconductors have interim hue".
Semiconductor conductivity can be adjusted by a process known as doping; involving adding impurities into "the crystal lattice". This in turn allows the creation of p-n junctions, which are then used to create transistors and diodes.
More about p-n junctions
P-n junctions are the boundary between p-type and n-type semiconductors. The are used to produce diodes that allow current to flow in one direction but not the other. Bias means applying a voltage across a p-n junction, forward bias means applying it in the direction of easy current flow, and reverse bias applying it in the opposite direction. In forward bias, the p-side is connected to the positive terminal of the battery and the n-side is connected to the negative terminal.
Transistors
The creation of transistors came eight years after the creation of PN barriers. Transistors can act as electronic switches in off/on state.
Logic Gates
Logic gates are created with diodes and transistors.
Now we have established why semiconductors are important, we can review some of the key milestones in their discovery and development that yielded the modern computer revolution.
1939 - Russell Ohl discovers the "PN barrier" later to be termed "PN junction". All diodes including LEDs are descendants of Ohl's work.
1947 - John Bardeen, Walter Brattain and William Shockley develop the transistor
1951 - Manufacture of transistors
1958 - First semiconductor Integrated Circuit
Where can we find more information about semiconductors and their role in business and society at large?
One useful source is the Semiconductor Industry Association (SIA).
First off, let's revise what a semiconductor actually is. A semiconductor (such as silicon, germanium and gallium arsenide) have conductivity in between a good conductor (metal such as copper) and an insulator (think of it as a mean value theorem type result applied to electrical conductivity). Why is that useful? To understand this, contemplate the following ditty praising the usefulness of semiconductors:
"Black and White are Boolean True,
But semiconductors have interim hue".
Semiconductor conductivity can be adjusted by a process known as doping; involving adding impurities into "the crystal lattice". This in turn allows the creation of p-n junctions, which are then used to create transistors and diodes.
More about p-n junctions
P-n junctions are the boundary between p-type and n-type semiconductors. The are used to produce diodes that allow current to flow in one direction but not the other. Bias means applying a voltage across a p-n junction, forward bias means applying it in the direction of easy current flow, and reverse bias applying it in the opposite direction. In forward bias, the p-side is connected to the positive terminal of the battery and the n-side is connected to the negative terminal.
Transistors
The creation of transistors came eight years after the creation of PN barriers. Transistors can act as electronic switches in off/on state.
Logic Gates
Logic gates are created with diodes and transistors.
Now we have established why semiconductors are important, we can review some of the key milestones in their discovery and development that yielded the modern computer revolution.
1939 - Russell Ohl discovers the "PN barrier" later to be termed "PN junction". All diodes including LEDs are descendants of Ohl's work.
1947 - John Bardeen, Walter Brattain and William Shockley develop the transistor
1951 - Manufacture of transistors
1958 - First semiconductor Integrated Circuit
Where can we find more information about semiconductors and their role in business and society at large?
One useful source is the Semiconductor Industry Association (SIA).
