TRYEngineering 2024 - 10

STEP 8
Doping
Doping, using an ion implanting machine, is the process of
changing the properties of silicon in a wafer to create different
chip components. We achieve this by introducing impurities
into the silicon, altering its conductivity. The type and amount
of impurities determine whether the silicon becomes n-type,
which has an excess of electrons, or p-type, which has a shortage
of electrons. Big machines called ion implanters manufacture
these, and where n and p meet (a PN junction), they form the
foundation of a transistor!
MAKE: Light-emitted diodes (LEDS) are actually just PN
junctions, so since we don't have a big implanter, we
place our already-made PN junctions (LEDS) from contact
to contact to complete the circuit.
STEP 9
Layers
Multiple repetitions of the photolithography, etching, and
doping processes build up the chip's complex structures.
Each repetition adds a new layer to the chip, with each layer
serving a specific function in the final circuit.
MAKE: Imagine you have repeated these
steps to make multiple layers.
STEP 10
Quality Control
Quality Control Engineers test the chip
to ensure they will actually work.
This technology can be delicate, and even
damage what is not visible to the human
eye, hindering its function. Therefore,
clean rooms are essential to keep out any
impurities and maximize the number of
chips a wafer creates.
MAKE: Carefully add your LEDs, and then
the QA Engineer will test each " chip "
using two wires and a battery to
see if your LEDs light up.
tryengineering.org/semiconductors // semiconductors.ieee.org/
TRYEngineering 2024

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