Method of plasma etching
AssigneeSPTS Technologies Limited
InventorBinte Kazemi Samira
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Abstract
An additive-containing aluminium nitride film is plasma etched. The additive-containing aluminium nitride film contains an additive element selected from scandium (Sc), yttrium (Y) or erbium (Er). A plasma is established within the chamber to plasma etch the additive-containing aluminium nitride film exposed within the trench. A ratio of the inert diluent gas flow rate to the sum of the BCl3 and Cl2 flow rates is in the range 0.45:1 to 0.75:1 and a ratio of the BCl3 flow rate to the Cl2 flow rate is in the range 0.75:1 to 1.25:1.
Claims18
A method of plasma etching an additive-containing aluminium nitride film, the additive-containing aluminium nitride film containing an additive element selected from scandium (Sc), yttrium (Y) or erbium (Er), the method comprising the steps of:
- placing a workpiece upon a substrate support within a plasma chamber, the workpiece comprising a substrate having an additive-containing aluminium nitride film deposited thereon and a mask disposed upon the additive-containing aluminium nitride film which defines at least one trench;
- introducing BCl3 gas into the plasma chamber with a BCl3 flow rate in sccm;
- introducing Cl2 gas into the plasma chamber with a Cl2 flow rate in sccm;
- introducing an inert diluent gas into the plasma chamber with an inert diluent gas flow rate in sccm;
- and
- establishing a plasma within the plasma chamber to plasma etch the additive-containing aluminium nitride film exposed within the trench;
- wherein a ratio of the inert diluent gas flow rate to a sum of the BCl3 and Cl2 flow rates is in the range 0.45:1 to 0.75:1 and a ratio of the BCl3 flow rate to the Cl2 flow rate is in the range 0.75:1 to 1.25:1.
A method plasma etching an additive-containing aluminium nitride film, the additive-containing aluminium nitride film containing an additive element selected from scandium (Sc), yttrium (Y) or erbium (Er), the method comprising the steps of:
- placing a workpiece upon a substrate support within a plasma chamber, the workpiece comprising a substrate having a metal film disposed thereon, an additive-containing aluminium nitride film deposited on the metal film and a mask disposed upon the additive-containing aluminium nitride film which defines at least one trench;
- performing a first, main, plasma etching step in which BCl3 gas, Cl2 gas and an inert diluent gas are introduced into the plasma chamber and a plasma is established within the plasma chamber to plasma etch a majority of the additive-containing aluminium nitride film exposed within the trench;
- and
- performing a second plasma etching step in which BCl3 gas and an inert diluent gas are introduced into the plasma chamber but Cl2 gas is not introduced into the plasma chamber and a plasma is established within the plasma chamber to plasma etch the remaining additive-containing aluminium nitride film exposed within the trench thereby revealing the metal film.
Dependencies are inferred from the claim text.