What is the main flow of integrated circuit manufacturing process?

Integrated circuit production technology and test system

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2 integrated circuit production process and test system

2. 1 Brief introduction of integrated circuit production process

Do you want to know how sophisticated IC chips are born from rough silicon ore? This section will unveil the mystery of IC manufacturing for you.

Do you know that?/You know what? Do you know that?/You know what? It usually takes 400 to 500 processes to manufacture an integrated circuit chip. But to sum up, it is generally divided into two parts: the road ahead

Front-end production and back-end production.

[1] Previous process

The process includes:

(1) converts crude silicon ore into high purity monocrystalline silicon.

(2) manufacturing various integrated circuit elements on the wafer.

(3) Testing the integrated circuit chip on the wafer.

[2] Subsequent process

The process includes:

(1) wafer cutting

(2) Packaging and testing of integrated circuit chips

There are several testing steps in the manufacturing process. Among them, the test of IC in the previous process is called wafer test. afterwards

The test of packaging integrated circuit chips in the process is called packaging test. In some cases, wafer testing is also carried out.

In the latter process, but in this paper, we classify wafer testing as the previous test.

Basic knowledge of semiconductors

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ADVANTEST

Previous production process:

& lt 1 & gt； Stretching of silicon rod

Melt polysilicon in a timely furnace, and then rely on.

A timely rod slowly pulls out a pure monocrystalline silicon rod.

seed

single crystal silicon

heater

Timely furnace

Molten silicon

diamond cutter

single crystal silicon

cleanser

thin pancake

gas

heater

thin pancake

Timely furnace

& lt2> Cutting Monocrystalline Silicon Rod

The monocrystalline silicon rod is cut to a certain thickness with a diamond knife.

Forming a wafer.

& lt3> polishing wafer

The surface of the wafer is polished into a mirror surface.

& lt4> Oxidizing wafer surface

The wafer is oxidized at 900 degrees-1 100 degrees.

In the furnace, pure oxygen is introduced on the surface of the wafer.

Forming silicon oxide.

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Integrated circuit production technology and test system

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Drop photoresist

electrode

electrode

vacuum pump

Reaction gas

thin pancake

thin pancake

Polishing plate

worn-out

Optical mask plate

camera lens

thin pancake

change

repeat

Forming the required on the wafer

All kinds of equipment

& lt5> covered with photoresist.

It is evenly distributed in the wafer by rotating centrifugal force.

The surface is covered with a layer of photoresist.

& lt6> forming a pattern on the wafer surface

Through optical mask and exposure technology

The surface of that waf is patterned.

& lt7> Corrosive agent

Etching is used to remove the corresponding oxide layer.

& lt8> oxidation, diffusion, chemical vapor deposition and ion implantation

Ions (phosphorus and boron) are implanted into the wafer, but

And then high-temperature diffusion is carried out to form various integrated devices.

& lt9> polishing (CMP)

Smooth the wafer surface.

Basic knowledge of semiconductors

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ADVANTEST

positive electrode

negative pole

thin pancake

Allow entry

Vent one's emotions

chip

thin pancake

Qinzhenka

signal

Using ADVANTEST's

T6573 test system

& lt 10 > shaped electrode

Aluminum is implanted into the corresponding position on the surface of the wafer,

Forming electrodes.

& lt 1 1 & gt； Wafer test

Measuring wafer

Try, put unqualified chips

Make a mark.

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Integrated circuit production technology and test system

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Post-production process: (Perform the following processing for the chips that have passed the wafer test)

Ε ? Ε ? Ε? Ε ? Ε ? Ε

Ε? Ε? Ε? Ε? Ε

Ε ? Ε? Ε? Ε

Ε ? Ε

diamond cutter

thin pancake

chip

basic framework

chip

ring

Chip frame

resin

< lt12 > cut the wafer.

Cut the chip from the wafer.

& lt 13 > fixed chip

Put the chip on a specific frame.

Cutting machine cutting

lead frame

& lt 14 & gt； connecting pin

Connect the chip and frame with 25 micron pure gold wire.

Pin on the connection.

& lt 15 > packaging

Encapsulate the chip with ceramics or resin.

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ADVANTEST

2.2 Tests and equipment in the previous procedures

Wafers should be tested before the previous process is completed, so that unqualified IC chips can be avoided and the number of unqualified IC chips can be reduced.

Necessary waste, reduce production costs.

T6655 10

camera lens

laser

chip

Test socket

signal

Performance board

chip

Aging plate

chip

pin

< lt16 > correction and forming (separation and casting)

The chip is separated from the frame line to manufacture the core.

The wires outside the sheet form a certain shape.

& lt 17 > aging (temperature and voltage) test

In improving the ambient temperature and working voltage of the chip

Under the condition of simulating the aging process of the chip to remove hair

Early failure products

Aging plate of aging machine

& lt 18 & gt； Finished product inspection and reliability test

Test the electrical characteristics and reject the unqualified chips.

Finished product inspection:

Electrical characteristics detection and appearance inspection

Reliability test:

Tested in the actual working environment, long working life.

life test

& lt 19 > tag

Print the product name on the chip with a laser.

Complete packaging

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Next, we will introduce the equipment needed in the previous test:

(1) test system: The test system generates various signals required for testing the integrated circuit and detects the output signals of the integrated circuit. root

According to the test results, the test system judges whether the tested integrated circuit is qualified or not, and transmits the test results to the wafer detector.

(2) Wafer probe: The wafer probe moves the wafer from the workbench to below the test head and presses the pins on the probe card on the IC.

On the chip, a good electrical contact is formed. The wafer detector will also ink the unqualified IC according to the test results of the test system.

Sealed.

(3) Probe card: The probe card is responsible for the electrical connection between the test system and the IC chip. There are many probes on the probe card.

During the test, these probes are pressed to the electrode plate of the IC chip, thus completing the electrical connection with the IC chip.

The early probes were tungsten probes several centimeters long. However, this tungsten probe cannot be used for signal frequency because of its own electrical characteristics.

When it is higher than 60MHz, it cannot cope with the narrow pitch pad.

After that, the probe on the new probe card solved the above limitations and can fully meet the testing requirements of today's equipment.

Next, we will introduce the repair of memory devices in wafer testing:

In the manufacturing process of high-density memory cells, some spare memory cells are usually recreated. So, if you find anything in the test,

If some storage units are unqualified, they can be replaced by spare storage units, thus improving the yield.

In wafer testing, it is necessary to analyze unqualified IC chips to determine how to use spare memory cells to repair these chips.

This analysis is called repair analysis, and the analysis algorithm is called repair algorithm.

After the analysis of the repair algorithm, if the IC chip can't be repaired, it will be classified as scrapped, and if it can be repaired, the circuit will be reset by using the laser repair instrument.

New connection, replace the damaged storage unit with the spare storage unit bar. The repaired IC chip needs to be tested again. Only by passing the test

After that, the wafer test is finished.

Finally, let's take a look at the wafer test analysis:

According to the position coordinates of the chip, the wafer test results can be displayed and a wafer map can be formed. From this chart, you can

Look at the distribution trend of bad chips. The classification of good/bad products can also rely on the data in the map without using an ink printer. correct

For memory devices, the spatial distribution of each unqualified bit can also be displayed. Error patterns of defective products and other analysis data pairs

It is of great benefit to reduce the defective rate.

Methods of eliminating discarded integrated circuits;

1. Ink the unqualified IC chip with an ink stick. In the latter process,

Discard the inked IC when cutting.

2. It is also possible to directly record the position of defective IC chips on the wafer without an ink printer.

Mark. In the subsequent process (when the wafer is cut), the IC is discarded according to this coordinate.

Small knowledge

Storage unit:

A memory cell is a circuit cell for storing data (0 or 1).

The simplest memory cell consists of a pair of transistors and a capacitor. For example, have

There are 64,000,000 memory cells in a memory device with a capacity of 64 megabits.

Magnetic resonance angiography:

In ADVANTEST, we use MRA (memory repair analyzer), that is, memory repair analysis.

Device) for high-speed analysis and get the repair scheme. That is, how to replace with spare cell strips?

Unit of the problem.

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Basic knowledge of semiconductors

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ADVANTEST

Figure 2- 1 wfbmap 3 shows the wafer fault bitmap.

2.3 Packaging Test/Final Test

In the process of completing the package test, we will use the test system and handler.

Just now we mentioned the tray for storing IC chips. Let's introduce it below.

WFBMAP3

WFBMAP3 (wafer failure bitmap) is a software provided by ADVANTEST for memory testing.

Pieces. Both the wafer map and the wafer failure bitmap can show the chips on the wafer.

Test results, but only the wafer failure bitmap can show each memory chip.

Test results of memory cells.

Small knowledge

What exactly does the test system do?

Answer: The test system will add a signal to the IC under test and then accept the output of the IC from its output.

A signal to judge whether an IC chip is qualified or not.

What is a trainer?

Answer: HANDLER is the manipulator, which moves the IC chip to be tested from the tray to the test platform.

Let's go After the test, it moves the qualified and unqualified IC chips to the corresponding IC chips by receiving signals.

Platform. The processor can also heat and cool the IC chip according to the test requirements.

Small knowledge

What is a tray?

A: Usually, for chips of various shapes, the chips are put in the tray by using the processor.

IC, we are relatively different from trays. On the test bench, HANGLER divided the IC into two parts according to P/F.

In different trays.

Small knowledge