Chip Manufacturing - How are Microchips made? | Infineon

Summary

This script outlines the intricate process of semiconductor manufacturing, starting from raw sand to finished chips. It details the transformation of silicon dioxide into pure silicon ingots, followed by slicing into wafers. The semiconductor nature of silicon is harnessed through doping to create P and N-type layers, essential for transistor construction. The script further explains the fabrication process involving photolithography, oxidation, etching, and metallization, all conducted in a cleanroom to ensure precision. The final steps include assembly and packaging, highlighting the importance of quality control for producing reliable semiconductor devices.

Takeaways

• 🏗️ Sand, primarily composed of silicon dioxide, is the starting material for semiconductor chips.
• 🔥 A high-temperature process involving carbon is used to remove oxygen from silica sand, creating pure silicon.
• 🔬 Silicon is a semiconductor material that can conduct electricity and act as an insulator.
• 🔋 Doping with impurities like boron or phosphorus alters silicon's conductivity to create n-type or p-type semiconductors.
• 🔩 Transistors, built on doped silicon layers, control electric voltages and currents and are crucial for microchips.
• 🛠️ The chip fabrication process requires a cleanroom environment to prevent contamination.
• 📏 Photo masks are used to transfer circuit designs onto silicon wafers through a process involving light exposure and etching.
• 🔍 Scanning electron microscopes are utilized to ensure the quality and precision of the chips at various production stages.
• 🔗 The final stage of fabrication involves assembling the individual chips into packages with terminals for circuit board mounting.
• 🌐 Microelectronics are integral to modern life, enabling innovations that improve safety, efficiency, and accessibility of technology.

Q & A

What is the primary component of sand used in chip manufacturing?

The primary component of sand used in chip manufacturing is silicon dioxide or silica.

How is silicon extracted from sand in the chip-making process?

Silicon is extracted from sand by combining it with carbon and heating it to an extremely high temperature to remove the oxygen.

What is the term for the extremely pure mono crystalline silicon used in chip manufacturing?

The extremely pure mono crystalline silicon used in chip manufacturing is called a silicon bull or ingot.

What are the most common diameters for silicon wafers?

The most common diameters for silicon wafers are 150, 200, and 300 millimeters.

Why are large diameter wafers preferred in chip manufacturing?

Large diameter wafers are preferred because they offer more space for chips, which can increase production efficiency.

What is the role of doping in the silicon wafer process?

Doping is the process of adding small quantities of specific atoms to the silicon wafer to make it conductive. Elements from the thirteenth or fifteenth group of the periodic table are used for this purpose.

What are the two types of conductive layers created by doping?

The two types of conductive layers created by doping are n-type, which is conductive with the addition of phosphorus, and p-type, which is conductive with the addition of boron.

What is a transistor and how does it function?

A transistor is the smallest control unit in microchips that controls electric voltages and currents. It can be switched between current flow (on) and no flow (off) by applying electrical charges to its terminals.

How are the layers for transistors created on a wafer?

The layers for transistors are created through a series of steps including oxidation, photoresist application, exposure through photo masks, etching, and doping.

What is a cleanroom and why is it necessary for chip fabrication?

A cleanroom is a dust-free environment with stable temperature and humidity levels, necessary for chip fabrication to prevent contamination that can ruin the microscopic structures of chips.

What happens during the final stage of chip fabrication known as assembly?

During the final stage of chip fabrication, individual chips are placed in a package, and terminals are attached to create a finished semiconductor device ready for use.

How are power semiconductors different from standard semiconductors?

Power semiconductors are designed to switch high electrical currents and voltages, and they often have integrated cooling areas to dissipate the heat generated during operation.

Outlines

00:00

💿 Silicon Wafer Production

This paragraph discusses the process of transforming raw silica sand into silicon wafers, which are the foundational elements for chip production. Silicon, the second most abundant element in the Earth's crust, is refined from sand through a series of complex chemical and physical procedures. The process involves combining sand with carbon and heating it to extreme temperatures to remove oxygen, resulting in pure mono crystalline silicon known as a silicon bull. These silicon bulls are then cut into thin wafers using a special sawing technique. The wafers are essential for subsequent chip production and are made conductive through the addition of impurity atoms like boron or phosphorus, a process known as doping. This doping process allows the silicon to either have an excess of electrons (n-type) or create electron holes (p-type), which are necessary for the semiconductor properties of chips.

05:02

🛠️ Fabrication of Integrated Circuits

The second paragraph delves into the intricate process of creating integrated circuits on silicon wafers. It starts with the design phase, where the chip's functions are defined, its properties are simulated, and its functionality is tested. The design is then transferred to photo masks, which are used to reproduce the microscopic structures of the chip in a dust-free environment known as a cleanroom. The fabrication process includes oxidizing the wafer surface, applying photoresist, exposing it to light through the photo mask, developing the exposed areas, etching off the developed oxide layer, and depositing conductive polysilicon. Further steps involve doping the silicon to alter its conductivity, etching contact holes for interconnections, and depositing metal alloys to create contacts. The process may be repeated multiple times to build up the layers necessary for the integrated circuit. The paragraph also emphasizes the stringent cleanliness and precision required in the production environment to ensure the quality of the chips.

10:06

🔩 Assembly and Quality Control of Semiconductor Devices

The final paragraph outlines the assembly and quality control stages of semiconductor production. After the integrated circuit is complete, individual chips are separated from the wafer, which involves leaving scribe lines and integrating test structures for immediate post-production measurements. The size of the resulting chips can vary significantly. The chips are then assembled into packages with terminals, creating finished semiconductor devices that can be mounted on circuit boards. The paragraph also highlights the use of special packages for power semiconductors designed for high-current applications like electric vehicles and renewable energy systems. The importance of advanced testing technologies and precision equipment in ensuring the quality and functionality of these tiny components is emphasized, as they are critical to the performance and reliability of the devices they are used in.

Keywords

💡Silicon Dioxide

Silicon dioxide, also known as silica, is a compound consisting of one silicon atom and two oxygen atoms. It is the primary component of sand and is crucial in semiconductor manufacturing. In the video, it is mentioned as the starting material for making silicon chips, highlighting its role in the foundational stage of chip production.

💡Mono Crystalline Silicon

Mono crystalline silicon is a type of silicon with a single crystal structure. It is highly valued in the semiconductor industry due to its superior electrical properties. The video describes the creation of a 'silicon bull', which is a pure mono crystalline silicon ingot used as the base for chip manufacturing.

💡Doping

Doping is the process of adding impurities to a semiconductor material to alter its electrical properties. In the video, it is explained that adding boron or phosphorus to silicon changes its conductivity, making it either P-type or N-type conductive, which is essential for creating transistors.

💡Transistors

Transistors are semiconductor devices that amplify or switch electronic signals and electrical power. They are the building blocks of modern electronics. The video emphasizes their importance in microchips, where they control electric voltages and currents.

💡Photoresist

Photoresist is a light-sensitive material used in semiconductor manufacturing to transfer a pattern from a photo mask to a silicon wafer. The video describes how photoresist is applied, exposed, and developed to create the pattern for etching layers in the chip fabrication process.

💡Cleanroom

A cleanroom is a controlled environment designed to reduce contamination, such as dust, airborne particles, and chemical vapors. The video mentions that chips are manufactured in a cleanroom to ensure the microscopic structures of a chip are reproduced flawlessly.

💡Ion Implantation

Ion implantation is a process in which ions are accelerated and embedded into a substrate to modify its physical and chemical properties. In the video, it is used to introduce impurity atoms into silicon to change its conductivity during the doping process.

💡Wafer

A wafer is a thin slice of semiconductor material, such as silicon, on which microelectronic circuits are built. The video explains that wafers are cut from silicon bulls and serve as the base for building chips.

💡Scribing Line

A scribing line is a path left between individual chips on a wafer to prevent damage during the sawing process. The video mentions that chips are not lined up flush with each other due to the scribing line.

💡Semiconductor Device

A semiconductor device is a device that exploits the properties of semiconductors to control the flow of electrical current. The video describes the final stage of fabrication where individual chips are assembled into a package, turning them into finished semiconductor devices.

💡Infineon

Infineon is a semiconductor company that designs and produces a wide range of semiconductor devices. The video concludes by mentioning Infineon, suggesting that the company is involved in the production of the microelectronics discussed throughout the video.

Highlights

Sand, primarily composed of silicon dioxide, is the starting material for chips.

Silicon is the second most abundant element in the Earth's crust.

Complex chemical and physical processes are required to purify silicon for chip production.

Silicon is converted from silica sand by combining it with carbon and heating.

Extremely pure mono crystalline silicon ingots, called bulls, are used in chip production.

Silicon wafers are cut from silicon bulls using a special sawing technique.

Silicon is a semiconductor, capable of conducting electricity and acting as an insulator.

Doping with impurity atoms like boron and phosphorus alters silicon's conductivity.

Transistors, built on doped wafers, are the fundamental control units in microchips.

Transistors control electric voltages and currents, crucial for electronic circuits.

The chip fabrication process begins with layout and design, involving billions of transistors.

Photo masks are used to transfer circuit designs onto silicon wafers.

Cleanrooms with stringent standards are essential for chip fabrication.

Wafers undergo multiple steps including oxidation, photoresist application, and etching.

Doping introduces impurity atoms to change the silicon's conductivity.

Metal alloys are deposited to create contacts and interconnections within the wafer.

Chemical mechanical polishing ensures a smooth finish for the insulation layer.

Final fabrication stages include assembly and packaging of individual chips.

Quality control is maintained through testing at every step of the fabrication process.

Microelectronics play a key role in creating innovative semiconductor solutions for a better future.

Transcripts

you

all ships start out with a very simple

raw material sand sand is primarily made

up of silicon dioxide or silica silicon

is the second most abundant element in

the Earth's crust but is only ever found

as a compound with oxygen complex

chemical and physical processes are

required to ensure that silicon crystals

meets the high production standards that

apply to chips to convert silica sand to

silicon the sand is combined with carbon

and heated to an extremely high

temperature to remove the oxygen a

number of other steps are required to

create the finished product namely an

extremely pure mono crystalline silicon

ingot called a bull with only one

impurity atom for every 10 million

silicon atoms silicon bulls are

fabricated in a range of different

diameters the most common sizes are 150

200 and 300 millimeters wafers with

large diameters offer more space for

chips extremely thin wafers are then cut

from the silicon Bulls using a special

sawing technique these wafers are the

basic building blocks for subsequent

chip production

silicon is a semiconductor this means it

can conduct electricity and also act as

an insulator it's atomic structure looks

like this every silicon atom has four

outer electrons there are no free charge

carriers as a result the pure mono

crystalline silicon is non conductive at

room temperature to allow it to become

conductive small quantities of specific

atoms are added as impurities to the

wafer these impurity atoms must have a

number of outer electrons that is either

one more or one less than that of

silicon silicon is in the fourteenth

group of the periodic table of elements

this means that elements in the

thirteenth or fifteenth group have to be

used in this process referred to as

doping boron and phosphorus atoms are

the most suitable elements in these

groups they are very close to silicon on

the periodic table and therefore have

very similar properties phosphorus has

five outer electrons when it is inserted

into the silicon crystal lattice the

fifth phosphorus electron can move

freely this means that the silicon

phosphorus crystal is n conductive

in contrast boron atoms only have three

outer electrons when they are introduced

into the silicon lattice one silicon

electron has nothing to bond to this

creates electron holes the holes move

through the crystal like positively

charged particles making the material P

conductive

[Music]

transistors are built on the P and n

conductive layers that exist in a doped

wafer transistors are the smallest

control units in microchips their job is

to control electric voltages and

currents and they are by far the most

important components of electronic

circuits every transistor on a chip

contains P and n conductive layers made

of silicon crystals they also have an

additional layer of silicon oxide which

acts as an insulator a layer of

electrically conductive polysilicon is

applied on top of this every transistor

has three terminals the middle one is

attached to the gate which is the

electrically conductive polysilicon if

an electrical charge is applied to only

the two outer terminals electricity

cannot flow as the transistor is blocked

this changes however if an additional

charge is applied to the middle terminal

electrons from the P layer are then

pulled toward the middle terminal and

accumulate at the area bordering the

silicon crystal and the insulating gate

oxide

a channel then forms underneath the gate

between the islands of n conductive

material electrons can now flow through

this channel the electrical circuit is

closed in this way the transistor can be

switched back and forth between current

and Nabal and disabled between 0 & 1 on

and off but how are these layers created

on a wafer the process to manufacture

chips from a wafer starts with the

layout and design phase highly complex

chips are made up of billions of

integrated and connected transistors

enabling sophisticated circuits such as

microcontrollers and crypto chips to be

built on a semiconductor surface

measuring just a few square millimeters

in size the sheer number of components

calls for an in-depth design process

this entails defining the chips

functions simulating its technical and

physical properties testing its

functionality and working out the

individual transistor connections

special design tools are used to draw up

the plans for integrated circuits and

develop a three-dimensional architecture

of sandwich layers this blueprint is

transferred to photo masks

providing geometric images of the

circuits the photo masks are used as

image templates during the subsequent

chip fabrication process to ensure that

the microscopic structures of a chip are

reproduced flawlessly they have to be

fabricated in a dust-free environment

with stable temperature and humidity

levels in other words they have to be

made in a cleanroom a cleanroom is a

room in which no more than one particle

of dust larger than 0.5 micrometers is

permitted in around 10 litres of air

this is even cleaner than the air in an

operating room

the ventilation filtration and supply

systems in a cleanroom therefore have to

be extremely sophisticated several

million cubic meters of air are

circulated every hour and hundreds of

air volume regulators maintain a

constant airflow employees in these

production areas have to abide by an

extremely strict dress code they are not

permitted to smoke before work or wear

any makeup or jewelry cleanroom

production areas can only be accessed

through a special airlock chips are

built on a base wafer cut from a silicon

pool depending on their size

several dozen or several thousand chips

can be fabricated on one wafer

first of all the surface of the wafer is

oxidized in a high-temperature furnace

operating at approximately 1,000 degrees

Celsius to create a non conductive layer

then a photoresist material is uniformly

distributed on this non conductive layer

using centrifugal force this coating

process creates a light-sensitive layer

the wafer is then exposed to light

through the photo mask in special

exposure machines known as steppers

during this process coaster sized areas

of the chip template known as recta

khals are used to transfer the complex

geometric patterns of the circuit design

to the silicon wafer the exposed area of

the chip pattern is developed revealing

the layer of oxide below the unexposed

part remains as is protecting the layer

of oxide after this the exposed layer of

oxide is etched off in the areas that

have been developed using wet or plasma

etching

with plasma etching special gasses bond

with the substrate to be removed in the

reaction chamber this enables

microscopic layers to be removed in the

windows that were exposed and developed

in the previous step once the

photoresist residue has been stripped

and the wafer has been cleaned the wafer

undergoes further oxidation electrically

conductive polysilicon is deposited on

this insulation layer then photoresist

is applied again and the wafer is

exposed to light through the mask the

exposed photoresist is stripped again

now the polysilicon and the thin oxide

layer are etched off these two layers

only remain intact in the centre under

the photoresist the next step is the

doping process where impurity atoms are

introduced into the exposed silicon and

ion implanter is used to shoot impurity

atoms into the silicon this changes the

conductivity of the exposed silicon by

fractions of a micrometer

after the photoresist residue has been

stripped another oxide layer is applied

the wafer undergoes another cycle of

applying photoresist exposure through

the mask

and stripping contact holes are etched

to provide access to the conductive

layers enabling the contacts and

interconnections to be integrated in the

wafer this is done by depositing metal

alloys onto the wafer in sputtering

machines

[Music]

once again the photoresist and masks are

applied the unexposed strips remain as

is after the etching process providing a

point of contact to the underlying

layers to give the insulation layer

above the interconnections the smooth

finish it requires a chemical mechanical

process is used to polish away excess

material with micrometer accuracy these

individual steps may be repeated

multiple times in the fabrication

process until the integrated circuit is

complete depending on the size and type

of chip the wafer will now contain

anything from several dozen to thousands

of chips individual chips are usually

sought out of the wafer the chips are

not lined up flush with each other on

the wafer because tiny parts of the

wafer splinter off during the sawing

process a certain amount of space known

as the scribe line is always left

between the individual chips test

structures are also integrated in the

space between the chips and used to take

measurements immediately after

production these tech structures are

destroyed during the sawing process the

size of the resulting chips typically

varies between one square millimeter and

a few square centimeters the final stage

of fabrication is assembly here the

individual chips are placed in a package

and terminals are attached the result is

a finished semiconductor device which

can be mounted on circuit boards using

different types of terminals over a

thousand connection contacts can be

realized here are some examples of ready

packaged semiconductor components

special larger packages are used for

power semiconductors intended for

applications such as trains electric

cars solar panels and wind turbines

these power semiconductors are designed

to switch electrical currents of up to

several hundred amps and voltages that

run into the thousands

switching at this level generates high

temperatures and this heat has to be

dissipated via cooling areas integrated

into the packages here you can see some

fully packaged power semiconductors

cutting-edge technologies used for

testing at every step in the fabrication

process to ensure the highest quality

levels in chip yield researchers and

developers use scanning electron

microscopes to repeatedly check the

chips at different points in the

production process

if we compare today's micro electronics

with human hair we can see just how

small these devices are the equipment

used to check components and analyze

defects is just as precise these high

levels of precision and quality are

essential at every stage of the workflow

from the production of silicon bulls

through the cleaning room fabrication to

quality control in order to deliver

these tiny building blocks that have

such a big impact on our lives today and

in the future after all demand is rising

for innovative semiconductor solutions

that make life easier safer and greener

for technology that achieves more

consumes less and is available to

everyone

Micro Electronics is the key to a better

future part of your life part of

tomorrow Infineon