Specific Process Knowledge/Thin film deposition/Temescal: Difference between revisions
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== | ==Deposition rate and thickness measurement accuracy== | ||
The machine measures the thickness of the growing film with a Quartz Crystal Microbalance or QCM. The machine calls it the Xtal (crystal). This is a very thin piece of quartz that resonates at about 5-6 MHz when a voltage is applied across it. The resonance frequency varies with the mass of the crystal, and when material is deposited on one side of it, the frequency changes. This is measured by the crystal monitor, which can then calculate the deposited thickness. | The machine measures the thickness of the growing film with a Quartz Crystal Microbalance or QCM. The machine calls it the Xtal (crystal). This is a very thin piece of quartz that resonates at about 5-6 MHz when a voltage is applied across it. The resonance frequency varies with the mass of the crystal, and when material is deposited on one side of it, the frequency changes. This is measured by the crystal monitor, which can then calculate the deposited thickness. | ||
[[File:Sell_quartz_crystal_microbalance.jpg|100px|right|thumb|Quartz crystal microbalance with gold electrode. Image from RLC on EC21.com]] | [[File:Sell_quartz_crystal_microbalance.jpg|100px|right|thumb|Quartz crystal microbalance with gold electrode. Image from RLC on EC21.com]] | ||