Specific Process Knowledge/Thin film deposition/Deposition of Silicon Oxide/Deposition of Silicon Oxide using Lesker sputter tool: Difference between revisions
| Line 3: | Line 3: | ||
=Sputter deposition of SiO<sub>2</sub> using Sputter System (Lesker)= | =Sputter deposition of SiO<sub>2</sub> using Sputter System (Lesker)= | ||
SiO<sub>2</sub> can be sputter deposited with RF bias in the [[Specific_Process_Knowledge/Thin_film_deposition/Lesker| | SiO<sub>2</sub> can be sputter deposited with RF bias in the Sputter System (Lesker). You can find basic information about the pressure and max power to use and the expected deposition rate on the [[Specific_Process_Knowledge/Thin_film_deposition/Lesker|Equipment page]] here in LabAdviser. To see the deposition parameters used by others, look in the [http://labmanager.dtu.dk/function.php?module=Processlog&view=editlog&machid=244 Process Log] in LabManager. Below you will find deposition parameters and results of a study on the surface roughness and oxide insulation quality of the deposited films. | ||
==Surface roughness optimization== | ==Surface roughness optimization== | ||
| Line 32: | Line 32: | ||
<br> | <br> | ||
==Oxide insulation analysis== | |||
''by Bjarke Thomas Dalslet @Nanotech.dtu.dk'' | |||
The wafers in this analysis consisted of a Si substrate with no native oxide. A layer of SiO<math>_2</math> was reactively sputtered (9% O2 90 W 3.5 mTorr). After that, using a shadow mask, 200nm thick gold rectangles was electro deposited on top of the oxide. Gold was also electro deposited on the back side. Then the impedance as a function of frequency was recorded. | |||
The figure shows the measurements for different oxide thicknesses. Most of the measurements show perfect capacitors, although for illustration measurements with a few pinholes and with many pinholes is also shown for the 20 nm sample. | |||
The success rate for the different thicknesses can be seen in the table, together with the number of samples measured and the number of perfect capacitors. | |||
It is possible to make perfect capacitors with oxide thicknesses down to and including 5 nm and possibly even thinner, although the failure rate increases. Bear in mind, though that each structure measured here has an area of 8 mm<sup>2</sup> - for a 1 mm<sup>2</sup> structure the failure rate would be much lower, assuming the short circuits are not located on the sides of the structures. | |||
[[Image:Lesker_Impedance_Bjarke.png|600px|alt text]] | |||
{| {{table}} border="1" cellspacing="0" cellpadding="8" | |||
| align="center" style="background:#f0f0f0;"|'''Name''' | |||
| align="center" style="background:#f0f0f0;"|'''Thickness [nm]''' | |||
| align="center" style="background:#f0f0f0;"|'''# samples measured''' | |||
| align="center" style="background:#f0f0f0;"|'''# good capacitors''' | |||
| align="center" style="background:#f0f0f0;"|'''Success rate [%]''' | |||
|- | |||
| 38||5||11||1||9 | |||
|- | |||
| 39||10||10||2||20 | |||
|- | |||
| 40||20||7||3||43 | |||
|- | |||
| 41||30||7||7||100 | |||
|- | |||
| 37||50||7||7||100 | |||
|- | |||
|} | |||
<br> | <br> | ||
==Tensile stress in SiO<sub>2</sub> films deposited at high temperature== | ==Tensile stress in SiO<sub>2</sub> films deposited at high temperature== | ||
In 2017 Radu Malureanu deposited SiO<sub>2</sub> at 600 °C in order to obtain films with a high tensile stress. More information on this study can be found [[Specific_Process_Knowledge/Thin_film_deposition/Lesker/Stress_dependence_on_sputter_parameters_in_the_Lesker_sputter_system|here]]. | In 2017 Radu Malureanu deposited SiO<sub>2</sub> at 600 °C in order to obtain films with a high tensile stress. More information on this study can be found [[Specific_Process_Knowledge/Thin_film_deposition/Lesker/Stress_dependence_on_sputter_parameters_in_the_Lesker_sputter_system|here]]. | ||