Atomic Layer Deposition: Process Demonstration

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From the course by Duke University

Nanotechnology: A Maker’s Course

459 ratings

Duke University

Nanotechnology: A Maker’s Course

459 ratings

How can we create nano-structures that are 10,000 times smaller than the diameter of a human hair? How can we “see” at the nano-scale? Through instruction and lab demonstrations, in this course you will obtain a rich understanding of the capabilities of nanotechnology tools, and how to use this equipment for nano-scale fabrication and characterization. The nanoscale is the next frontier of the Maker culture, where designs become reality. To become a Nanotechnology Maker pioneer, we will introduce you to the practical knowledge, skills, and tools that can turn your nanotechnology ideas into physical form and that enable you to image objects at the nano-scale. This course has been developed by faculty and staff experts in nano-fabrication, electron beam microscopy, and nano-characterization through the Research Triangle Nanotechnology Network (RTNN). The RTNN offers training and use of the tools demonstrated in this course to schools and industry through the United States National Nanotechnology Coordinated Infrastructure program. The tools demonstrated in this course are available to the public through the RTNN.

From the lesson

Nanofabrication: Vapor Deposition

We will look at some techniques for making things with nanotechnology using thin film techniques; in this module you will learn to describe and compare atomic layer deposition, chemical vapor deposition, and plasma-enhanced chemical vapor deposition.

Atomic Layer Deposition: Basic Function6:02

Atomic Layer Deposition: Process Demonstration4:12

Meet the Instructors

Nan M. Jokerst
J. A. Jones Professor of Electrical and Computer Engineering
Electrical and Computer Engineering, Duke University
Carrie Donley
Director of CHANL (Chapel Hill Analytical and Nanofabrication Laboratory)
Applied Physical Sciences, UNC Chapel Hill
James Cahoon
Assistant Professor
Chemistry, UNC Chapel Hill
Jacob Jones
Professor
Materials Science and Engineering, North Carolina State University

Hello, I'm Veena Misra.

I'm the director of the NSF Nano Systems Engineering Research Center called ASSIST,

and a professor in the Department of Electrical and Computer Engineering at NC State.

Today, I'm joined by Bongmook Lee,

a research assistant professor in the Department of Electrical and Computer Engineering,

also at NC State.

Bongmook will give you a demonstration of the atomic layer deposition process.

Today, we will be using a Cambridge Nanotech Savannah ALD system.

This round chamber on top is where we will place

our substrate and the ALD process will take place.

The base of this machine safely houses all of

the precursor sources to deposit the thin film material,

as well as the vacuum pumps to pressurize

the chamber and remove atmospheric contaminants.

The canisters that contain

the gaseous precursors required for a deposition process are loaded here.

There's room for five precursors here and with this system,

we can deposit up to five different thin films.

The entire deposition process is controlled by a computer.

We must vent the chamber so that we can open it and place our substrate

like the silicon wafer or sample pieces glass and more.

The vacuum system is also controlled by the computer.

We are going to use a system to deposit Hafnium oxide onto a silicon wafer.

This type of film is used as a gate insulator layer in modern transistors.

Now that the chamber pressure reaches atmospheric pressure,

we can open the chamber door.

This chamber is designed for four inch silicon wafers.

Our wafer will fit into this round inset.

We place our wafer into the chamber.

Each pre-cursor and reactant vapor along with

some nitrogen carrier gas are introduced through this hole on the left one at a time.

Any unreacted precursor will be pumped out of the system through the hole on the right.

Now, we close the chamber door and pump the system

back down to remove ambient conditions and contaminants.

Every part of the process will be controlled and

automated by the computer to the conditions that Bongmook sets.

The conditions that the deposition will take place under is called a recipe.

We can change the recipe and the deposition parameters through this interface.

The pressure of the chamber is measured by a vacuum gauge shown here.

Control of the valves for the precursors and purge gas canisters are here.

Once we have the conditions set up,

we simply start the process by clicking, Run.

We receive a live feed of the process conditions on this graph,

where we can see a pressure change when

the precursor is pulsed into the chamber as shown here.

The duration of the ALD process will

depend on the thickness of the film you want to grow.

Some processes can take up to a few hours to complete.

It is important to make sure everything starts correctly

but not necessary to sit and watch the whole time.

Now that the ALD process has had time to complete,

we are ready to vent the chamber and remove our sample.

We remove the sample from the chamber and close the door.

Here is a silicon wafer with a Hafnium oxide film that we

deposited on the surface through our ALD process.

It may not look much different but let's compare it to

an untreated silicon wafer like the one we put in the chamber originally.

You can notice the Hafnium oxide deposited Wafer has a brownish color to it.

This is due to the presence of

our Hafnium oxide film that we deposited on to the surface.

This concludes the ALD process demonstration.

Thank you for watching.

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