Varios

Silicon Wafer Processing
Dr. Seth P. Bates
Applied Materials
Summer, 2000

Objective
To provide an overview for manufacturing systems students of the steps and processes required to make
integrated circuits from blank silicon wafers.

Goals
The Transfer Plan provides a curriculum covering the process of manufacturing integrated circuits from
the silicon wafer blanks, using theequipment manufactured by Applied Materials, Lam Research, and
others of its competitors. The curriculum will be modular, with each module covering a process in
sequence. This curriculum will be developed for internet access.

Outline
Introduction
Preparation of the Silicon Wafer Media
Silicon Wafer Processing Steps

Silicon Wafer Processing
Outline of Contents

Introduction................................................................................................................ 2
Preparation of the Silicon Wafer Media...................................................................... 3
Crystal Growth and Wafer Slicing Process
Thickness Sorting
Lapping & Etching Processes
Thickness Sorting and Flatness Checking
Polishing Process
Final Dimensional and ElectricalProperties Qualification
Silicon Wafer Processing Steps ................................................................................. 8
Fabrication
Diffusion
Coat-Bake
Align
Develop
Dry etch
Wet etch & clean
Photolithography
Implant / Masking Steps
Die Attach / Wire Bond
Encapsulation
Lead Finish / Trim and Form
Final Testing / Shipping

Seth Bates

SJSU / Applied Materials /IISME-ETP

page 1

Introduction
The processing of Silicon wafers to produce integrated circuits involves a good deal of chemistry and
physics. In order to alter the surface conditions and properties, it is necessary to use both inert and toxic
chemicals, specific and unusual conditions, and to manipulate those conditions with both plasma-state
elements and with RF (Radio Frequency) energies.Starting with thin, round wafers of silicon crystal, in
diameters of 150, 200, and 300mm, the processes described here build up a succession of layers of
materials and geometries to produce thousands of electronic devices at tiny sizes, which together
function as integrated circuits (ICs). The devices which now occupy the surface of a one-inch square IC
would have occupied the better part of amedium-sized room 20 years ago, when all these devices
(transistors, resistors, capacitors, and so on) were only available as discreet units.
The conditions under which these processes can work to successfully transform the silicon into ICs
require an absolute absence of contaminants. Thus, the process chambers normally operate under
vacuum, with elemental, molecular, and other particulatecontaminants rigorously controlled. In order to
understand these processes, then, we will begin the study of semiconductor processing with an overview
of vacuum systems and theory, of gas systems and theory, as applied specifically to these tools, and of
clean room processes and procedures
The semiconductor industry reflects and serves an extraordinary revolution in both materials science and
indata processing and storage. As recently as 1980, most individuals had no idea that computers would
ever impact their personal lives. Today, many families own one or two computers, and use many other
computers and dedicated processor systems in their appliances and automobiles. The intrusion of
electronics and computer technology into our lives and the devices we use daily is growing at anexponential rate, and Moore’s Law still applied in the computer world. This is one of the few markets in
which, as time passes, the power and capacity of the products grows steadily, while the cost of that
power and capacity drops.
Today, only twenty years later, we are continually pushing the envelope of capabilities of the data
processing and storage systems that are now in the mainstream....