Atomic layer deposition - Revision history

Harry at 15:05, 15 June 2026

2026-06-15T15:05:25Z

← Older revision		Revision as of 15:05, 15 June 2026
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	* The ratio of the ''oxide thickness'' over the ''growth cycles'' gives the '''growth per cycle (GPC)'''		* The ratio of the ''oxide thickness'' over the ''growth cycles'' gives the '''growth per cycle (GPC)'''

	===TMA example===		=TMA example=
	To enrich the simplistic visualisation given above, an example of an ALD cycle to form a layer of AlO<sub>x</sub> is given in this section.		To enrich the simplistic visualisation given above, an example of an ALD cycle to form a layer of AlO<sub>x</sub> is given in this section.

Harry at 15:04, 15 June 2026

2026-06-15T15:04:56Z

← Older revision		Revision as of 15:04, 15 June 2026
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	[[File: TMA_init_final.jpeg\|none\|thumb\|400px\| The initial and final state of the surface in an ALD cycle. Both surfaces have hydroxyl groups that are susceptible to a new ALD cycle]]		[[File: TMA_init_final.jpeg\|none\|thumb\|400px\| The initial and final state of the surface in an ALD cycle. Both surfaces have hydroxyl groups that are susceptible to a new ALD cycle]]

	==An ALD cycle in Savannah==		=An ALD cycle in Savannah=
	The following image is a part of the "playlist" in the ALD2 system corresponding to the deposition sequence.		The following image is a part of the "playlist" in the ALD2 system corresponding to the deposition sequence.
	[[File:ALD_AL2_sequence.jpeg\|none\|thumb\|400px\| An example of a playlist from the ALD2 tool corresponding to the deposition sequence]]		[[File:ALD_AL2_sequence.jpeg\|none\|thumb\|400px\| An example of a playlist from the ALD2 tool corresponding to the deposition sequence]]

Harry: /* An ALD cycle in Savannah */

2026-06-15T15:04:15Z

An ALD cycle in Savannah

← Older revision		Revision as of 15:04, 15 June 2026
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	==An ALD cycle in Savannah==		==An ALD cycle in Savannah==
	The following image is a part of the "playlist" in the ALD2 system corresponding to the deposition sequence.		The following image is a part of the "playlist" in the ALD2 system corresponding to the deposition sequence.
	[[File:ALD_AL2_sequence.jpeg\|none\|thumb\|400px\| An example of a playlist from the ALD2 tool corresponding to the deposition sequence~~. In the green square colour, the four ALD steps of a cycle are included~~]]		[[File:ALD_AL2_sequence.jpeg\|none\|thumb\|400px\| An example of a playlist from the ALD2 tool corresponding to the deposition sequence]]

	# '''pulse''': An electrical signal turns on the precursor valve, introducing precursor A		# '''pulse''': An electrical signal turns on the precursor valve, introducing precursor A

Harry: /* Principles */

2026-06-15T15:03:58Z

Principles

← Older revision		Revision as of 15:03, 15 June 2026
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	* During the coating procedure, N<sub>2</sub> is used as a carrier gas in a user-determined flow, and a scroll pump attached to the exhaust continuously pumps the byproducts from the reactor.		* During the coating procedure, N<sub>2</sub> is used as a carrier gas in a user-determined flow, and a scroll pump attached to the exhaust continuously pumps the byproducts from the reactor.
	* The ratio of the ''oxide thickness'' over the ''growth cycles'' gives the '''growth per cycle (GPC)'''		* The ratio of the ''oxide thickness'' over the ''growth cycles'' gives the '''growth per cycle (GPC)'''

			===TMA example===
			To enrich the simplistic visualisation given above, an example of an ALD cycle to form a layer of AlO<sub>x</sub> is given in this section.

			The single-cycle sequence is divided based on earlier descriptions.
			[[File:TMA_steps.jpeg\|none\|thumb\|400px\| The four steps for the deposition of one layer of AlO<sub>x</sub>. Illustrations are taken from the Savannah manual]]

			[[File: TMA_init_final.jpeg\|none\|thumb\|400px\| The initial and final state of the surface in an ALD cycle. Both surfaces have hydroxyl groups that are susceptible to a new ALD cycle]]

	==An ALD cycle in Savannah==		==An ALD cycle in Savannah==
	The following image is a part of the "playlist" in the ALD2 system corresponding to the deposition sequence.		The following image is a part of the "playlist" in the ALD2 system corresponding to the deposition sequence.
	[[File:ALD_AL2_sequence.jpeg\|none\|thumb\|400px\| ~~Part~~ of ~~the~~ playlist from ALD2 tool corresponding to the deposition sequence]]		[[File:ALD_AL2_sequence.jpeg\|none\|thumb\|400px\| An example of a playlist from the ALD2 tool corresponding to the deposition sequence. In the green square colour, the four ALD steps of a cycle are included]]

	# '''pulse''': An electrical signal turns on the precursor valve, introducing precursor A		# '''pulse''': An electrical signal turns on the precursor valve, introducing precursor A

Harry: /* Principles */

2026-06-15T12:50:41Z

Principles

← Older revision		Revision as of 12:50, 15 June 2026
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	=Principles=		=Principles=
	A repetitive sequence of four steps, so called '''cycle''', achieves the coating of the surface.		A repetitive sequence of four steps described below, so called '''cycle''', achieves the coating of the surface.
	==Cycle sequence==		==Cycle sequence==
	'''Initial state:''' The surface of the material is terminated with hydroxyl groups (formed during contact with air).		'''Initial state:''' The surface of the material is terminated with hydroxyl groups (formed during contact with air).

Harry at 12:50, 15 June 2026

2026-06-15T12:50:10Z

← Older revision		Revision as of 12:50, 15 June 2026
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	==An ALD cycle in Savannah==		==An ALD cycle in Savannah==
	The following image is a part of the "playlist" in the ALD2 system corresponding to the deposition sequence.		The following image is a part of the "playlist" in the ALD2 system corresponding to the deposition sequence.
			[[File:ALD_AL2_sequence.jpeg\|none\|thumb\|400px\| Part of the playlist from ALD2 tool corresponding to the deposition sequence]]

	# '''pulse''': An electrical signal turns on the precursor valve, introducing precursor A		# '''pulse''': An electrical signal turns on the precursor valve, introducing precursor A
	# '''wait''': The reaction products and the non-reacted molecules of precursor A are pumped out of the system for a set time		# '''wait''': The reaction products and the non-reacted molecules of precursor A are pumped out of the system for a set time

Harry: /* Cycle sequence */

2026-06-15T12:38:11Z

Cycle sequence

← Older revision		Revision as of 12:38, 15 June 2026
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	A simplistic visualisation of a binary reaction sequence is illustrated below.		A simplistic visualisation of a binary reaction sequence is illustrated below.

	[[File:ALD_sequence.jpeg\|none\|thumb\|~~200px~~\| Schematic representation of ALD using self-limiting surface chemistry and an AB binary reaction sequence.‎<ref> George, Steven M. "Atomic layer deposition: an overview." Chemical reviews 110.1 (2010): 111-131. ‎</ref>]]		[[File:ALD_sequence.jpeg\|none\|thumb\|400px\| Schematic representation of ALD using self-limiting surface chemistry and an AB binary reaction sequence.‎<ref> George, Steven M. "Atomic layer deposition: an overview." Chemical reviews 110.1 (2010): 111-131. ‎</ref>]]

	==Notes==		==Notes==

Harry: /* Cycle sequence */

2026-06-15T12:37:46Z

Cycle sequence

← Older revision		Revision as of 12:37, 15 June 2026
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	'''Final state:''' A single oxide layer has been formed and surface hydroxyl groups are used again to perform another cycle.		'''Final state:''' A single oxide layer has been formed and surface hydroxyl groups are used again to perform another cycle.

	A simplistic visualisation of a binary reaction sequence is illustrated below.		A simplistic visualisation of a binary reaction sequence is illustrated below.

			[[File:ALD_sequence.jpeg\|none\|thumb\|200px\| Schematic representation of ALD using self-limiting surface chemistry and an AB binary reaction sequence.‎<ref> George, Steven M. "Atomic layer deposition: an overview." Chemical reviews 110.1 (2010): 111-131. ‎</ref>]]

	==Notes==		==Notes==

Harry: /* Principles */

2026-06-15T12:29:49Z

Principles

← Older revision		Revision as of 12:29, 15 June 2026
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	A repetitive sequence of four steps, so called '''cycle''', achieves the coating of the surface.		A repetitive sequence of four steps, so called '''cycle''', achieves the coating of the surface.
	==Cycle sequence==		==Cycle sequence==
	# The surface of the material is terminated with hydroxyl groups (formed during contact with air).		'''Initial state:''' The surface of the material is terminated with hydroxyl groups (formed during contact with air).
	# '''The first precursor is introduced:''' The precursor molecules react with the surface hydroxyles forming a single saturated monolayer.		# '''The first precursor is introduced:''' The precursor molecules react with the surface hydroxyles forming a single saturated monolayer.
	# '''Evacuation:''' The byproducts of the reaction (methane - CH<sub>3</sub>) and the unreacted precursor molecules are pumped out of the chamber		# '''Evacuation:''' The byproducts of the reaction (methane - CH<sub>3</sub>) and the unreacted precursor molecules are pumped out of the chamber
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	# '''Evacuation:''' The byproducts of the reaction (methane - CH<sub>3</sub>) and the unreacted precursor molecules are pumped out of the chamber.		# '''Evacuation:''' The byproducts of the reaction (methane - CH<sub>3</sub>) and the unreacted precursor molecules are pumped out of the chamber.

	~~As a result, a~~ single oxide layer has been formed and surface hydroxyl groups are used again to perform another cycle.		'''Final state:''' A single oxide layer has been formed and surface hydroxyl groups are used again to perform another cycle.

			A simplistic visualisation of a binary reaction sequence is illustrated below.

	==Notes==		==Notes==
	* During the coating procedure, N<sub>2</sub> is used as a carrier gas in a user-determined flow, and a scroll pump attached to the exhaust continuously pumps the byproducts from the reactor.		* During the coating procedure, N<sub>2</sub> is used as a carrier gas in a user-determined flow, and a scroll pump attached to the exhaust continuously pumps the byproducts from the reactor.
	* The ratio of the ''oxide thickness'' over the ''growth cycles'' gives the '''growth per cycle (GPC)'''		* The ratio of the ''oxide thickness'' over the ''growth cycles'' gives the '''growth per cycle (GPC)'''

			==An ALD cycle in Savannah==
			The following image is a part of the "playlist" in the ALD2 system corresponding to the deposition sequence.
			# '''pulse''': An electrical signal turns on the precursor valve, introducing precursor A
			# '''wait''': The reaction products and the non-reacted molecules of precursor A are pumped out of the system for a set time
			# '''pulse''': An electrical signal turns on the precursor valve, introducing precursor B (water)
			# '''wait''': The reaction products and the non-reacted molecules of precursor B (water) are pumped out of the system for a set time
			# '''goto''': The loop command. It defines the line that the cycle will restart as well as the amount of cycles that you desire.

Harry: Created page with "An Atomic Layer Deposition (ALD) process is a vapor-phase, thin-film deposition method driven by the chemical saturation of surfaces, allowing for conformal coatings of surfaces with very high aspect ratios. The reason for this uniform coating lies in the '''saturative chemisorption''' of sequential cycles of precursor vapors. =Principles= A repetitive sequence of four steps, so called '''cycle''', achieves the coating of the surface. ==Cycle sequence== # The surface of..."

2026-06-15T10:09:10Z

Created page with "An Atomic Layer Deposition (ALD) process is a vapor-phase, thin-film deposition method driven by the chemical saturation of surfaces, allowing for conformal coatings of surfaces with very high aspect ratios. The reason for this uniform coating lies in the '''saturative chemisorption''' of sequential cycles of precursor vapors. =Principles= A repetitive sequence of four steps, so called '''cycle''', achieves the coating of the surface. ==Cycle sequence== # The surface of..."

New page

An Atomic Layer Deposition (ALD) process is a vapor-phase, thin-film deposition method driven by the chemical saturation of surfaces, allowing for conformal coatings of surfaces with very high aspect ratios. The reason for this uniform coating lies in the '''saturative chemisorption''' of sequential cycles of precursor vapors.

=Principles=
A repetitive sequence of four steps, so called '''cycle''', achieves the coating of the surface.
==Cycle sequence==
# The surface of the material is terminated with hydroxyl groups (formed during contact with air).
# '''The first precursor is introduced:''' The precursor molecules react with the surface hydroxyles forming a single saturated monolayer.
# '''Evacuation:''' The byproducts of the reaction (methane - CH3) and the unreacted precursor molecules are pumped out of the chamber
#'''Water (H20) is introduced:''' Water (H20) is pulsed into the reactor. This will remove the CH3 groups and create oxide bridges, and passivate the surface with hydroxyles.
# '''Evacuation:''' The byproducts of the reaction (methane - CH3) and the unreacted precursor molecules are pumped out of the chamber.

As a result, a single oxide layer has been formed and surface hydroxyl groups are used again to perform another cycle.

==Notes==
* During the coating procedure, N2 is used as a carrier gas in a user-determined flow, and a scroll pump attached to the exhaust continuously pumps the byproducts from the reactor.
* The ratio of the ''oxide thickness'' over the ''growth cycles'' gives the '''growth per cycle (GPC)'''