Abstract Title
Student Design and Construction of an Atomic Layer Deposition Chamber, and Its Use in Depositing Germanium Sulfide Thin Films
Abstract
GeS films are used throughout the semiconductor industry and are generally deposited by chemical vapor deposition. It has some shortcomings such as difficulties with depositing ultra-thin films and growth rates of films depending on many variables. Atomic layer deposition is another form of deposition that is becoming used in the semiconductor industry. ALD deposits reactants in atom thick layers by self-limiting surface reactions; the nature of the deposition causes a linear correspondence between film thickness and number of pulse cycles. ALD allows for precise control over film stoichiometry and film thickness.
A cold-wall ALD reactor was designed and constructed by students, and GeSx films were deposited in the ALD fashion. The reactor was constructed mainly from repurposed parts from previous studies by the lab. GeCl4 vapors and H2S were pulsed sequentially with Ar purging cycles between each pulse. An RF plasma was applied during cycles to aid in deposition. Pressure, temperature, and plasma power were kept constant between depositions, 200mTorr, 150 C, and 20W respectively. An in situ mass spectrometer was used to optimize the pulse and purge times. The resulting films were characterized by scanning electron microscope, energy dispersive x-ray spectroscopy, and x-ray diffraction.
Student Design and Construction of an Atomic Layer Deposition Chamber, and Its Use in Depositing Germanium Sulfide Thin Films
GeS films are used throughout the semiconductor industry and are generally deposited by chemical vapor deposition. It has some shortcomings such as difficulties with depositing ultra-thin films and growth rates of films depending on many variables. Atomic layer deposition is another form of deposition that is becoming used in the semiconductor industry. ALD deposits reactants in atom thick layers by self-limiting surface reactions; the nature of the deposition causes a linear correspondence between film thickness and number of pulse cycles. ALD allows for precise control over film stoichiometry and film thickness.
A cold-wall ALD reactor was designed and constructed by students, and GeSx films were deposited in the ALD fashion. The reactor was constructed mainly from repurposed parts from previous studies by the lab. GeCl4 vapors and H2S were pulsed sequentially with Ar purging cycles between each pulse. An RF plasma was applied during cycles to aid in deposition. Pressure, temperature, and plasma power were kept constant between depositions, 200mTorr, 150 C, and 20W respectively. An in situ mass spectrometer was used to optimize the pulse and purge times. The resulting films were characterized by scanning electron microscope, energy dispersive x-ray spectroscopy, and x-ray diffraction.
Comments
I feel like 200 words are fairly limiting. Even 50 more words would give a lot more breathing room.