Method for forming semiconductor device structure

A method for forming a semiconductor device structure, comprising:

• placing a substrate comprising a material layer thereon in a plasma chamber, wherein the plasma chamber comprises:
• a housing comprising a gas inlet at a top portion of the housing and a gas outlet at a bottom portion of the housing;
• a wafer support;
• an electrostatic electrode disposed in the wafer support;
• a first gas supply coupled to the wafer support;
• a plurality of gas channels disposed in a top portion of the wafer support and connected to the first gas supply for transferring heat generated by the electrostatic electrode to provide uniform temperature distribution;
• a first electrode array disposed outside the housing, comprising a plurality of first sub-electrodes arranged in a plurality of rows;
• a plurality of first matching units each electrically connected to one of the plurality of first sub-electrodes;
• and
• a second electrode array disposed in the housing, the second electrode array comprising a plurality of second sub-electrodes, wherein the first electrode array and the second electrode array are each arranged in a matrix having the same number of rows and columns, each of the first sub-electrodes has a circular spiral shape winding around a central region to form multiple turns when seen from a top-view, and each of the second sub-electrodes has a circular shape corresponding to the first electrode array when seen from a top-view, wherein each of the circular spiral shape of each of the plurality of first sub-electrodes is encircled by an insulating material that conforms to the same circular spiral shape, winding around the central region and forming multiple turns;
• supplying an etching gas from a second gas supply that is coupled to the plasma chamber into the plasma chamber through the gas inlet;
• applying a first RF power source to the plurality of first sub-electrodes of the first electrode array by the plurality of first matching units to form an etching plasma from the etching gas;
• adjusting a first distance between a first one of the plurality of first sub-electrodes and the substrate to generate a first plasma density over a first region of the substrate and a second distance between a second one of the plurality of first sub-electrodes and the substrate to generate a second plasma density over a second region of the substrate, wherein the first plasma density is different from the second plasma density;
• performing an etching process on the material layer using the etching plasma to form a first trench in the first region of the substrate and a second trench in the second region of the substrate, wherein the first trench etched under the first plasma density and the second trench etched under the second plasma density have different widths and substantially equal depth;
• and
• evacuating chemical byproducts and unwanted reagents from the plasma chamber through the gas outlet.

A method for forming a semiconductor device structure, comprising:

• placing a substrate comprising a material layer thereon in a plasma chamber, wherein the plasma chamber comprises:
• a housing comprising a gas inlet;
• a wafer support;
• an electrostatic electrode disposed in the wafer support;
• a first gas supply coupled to the wafer support;
• a plurality of gas channels disposed in a top portion of the wafer support and connected to the first gas supply for transferring heat generated by the electrostatic electrode to provide uniform temperature distribution;
• a first electrode array disposed outside the housing, comprising a plurality of first sub-electrodes arranged in a plurality of rows;
• a plurality of first matching units each electrically connected to one of the plurality of first sub-electrodes;
• and
• a second electrode array disposed in the housing, the second electrode array comprising a plurality of second sub-electrodes, wherein the first electrode array and the second electrode array are each arranged in a matrix having the same number of rows and columns, each of the first sub-electrodes has a circular spiral shape winding around a central region to form multiple turns when seen from a top-view, and each of the second sub-electrodes has a circular shape corresponding to the first electrode array when seen from a top-view, wherein each of the circular spiral shape of each of the plurality of first sub-electrodes is encircled by an insulating material that conforms to the same circular spiral shape, winding around the central region and forming multiple turns;
• supplying an etching gas from a second gas supply that is coupled to the plasma chamber into the plasma chamber through the gas inlet;
• applying a first RF power source to the plurality of first sub-electrodes of the first electrode array by the plurality of first matching units to form an etching plasma from the etching gas;
• adjusting a first distance between a first one of the plurality of first sub-electrodes and the substrate to generate a first plasma density over a first region of the substrate and a second distance between a second one of the plurality of first sub-electrodes and the substrate to generate a second plasma density over a second region of the substrate, wherein the first plasma density is different from the second plasma density;
• performing an etching process on the material layer using the etching plasma to form a first trench in the first region of the substrate and a second trench in the second region of the substrate, wherein the first trench etched under the first plasma density has a first width and a first depth, the second trench etched under the second plasma density has a second width and a second depth, the first width is different from the second width, and the first depth is substantially equal to the second depth;
• and
• performing a cleaning process after the etching process by supplying a cleaning gas from the second gas supply into the plasma chamber through the gas inlet.