Si (100) Wafers - Dry Etching

Si (100) Wafers - Dry Etching

Material Name: Si (100) wafers
Recipe No.: 1928
Primary Chemical Element in Material: Si
Sample Type: Wafer
Uses: Etching
Etchant Name: None
Etching Method: Dry etching
Etchant (Electrolyte) Composition: x...ClF3. Note: The volume/quantity was not shown in the referenced article and is therefore designated as an "x".
Procedure (Condition): Time: To 10 min, temperature: RT, gas flow: 20 cm3/min, pressure: 0.03 Torr, power: 70 W, bias: 10 V.
Note: Si (100) wafers used in structuring a RAM configuration device with poly-Si and SiO2. Pure Cl2 or ClF3 was evaluated in addition to ClF3 concentrations of 5, 30, and 80%. Primary etching was on the poly-Si. Etch rate vs. side removal of a pure C1F3 plasma was linear at 1900 A/min and 2 µm per side removal in 10 min. The Si:SiO2 etch ratio reduces with decrease of Cl2 toward pure C1F3 - atomic fluorine 42:1. Elch rate is unaffected by C1F3 concentration for lightly doped p- or n-type single crystals, undoped poly-Si and thermal SiO2 where SiO2 is less than 100 A/min with 0-100% CIF3. All others etched at an equal rate. There is a wafer quantity mass loading affect as shown on poly-Si etch rate of one wafer at about 3800 A/min to about 1900 A/min with six to seven wafers.
Reference: Flamm, D L et al. - J Electrochem Soc, 129,2755(1982).