Microwave plasma source for spatial plasma enhanced atomic layer deposition (PE-ALD) processing tool

A plasma source assembly comprising:

• a flat powered electrode having a first end and a second end and having an axis extending along an elongate axis of the plasma source assembly, the powered electrode having a width;
• a ground electrode on a first side of the powered electrode, the ground electrode spaced from the powered electrode to provide a gap between the powered electrode and the ground electrode so that the powered electrode is suspended within a dielectric comprising one or more of air, vacuum or inert gas, the ground electrode including a gas inlet;
• a dielectric on a second side of the powered electrode, the dielectric and second dielectric enclosing the powered electrode to prevent electrical contact between the powered electrode and the ground electrode, the dielectric having a gas channel extending along the elongate axis of the plasma source assembly, the gas inlet is in fluid communication with one or more plenum extending along elongate axis, the one or more plenum in fluid communication with the gas channel through one or more gas conduits;
• a first microwave generator electrically coupled to the first end of the powered electrode through a first feed, the first microwave generator operating at a first frequency;
• and
• a second microwave generator electrically coupled to the second end of the powered electrode through a second feed, the second microwave generator operating at a second frequency,
• wherein the first frequency and the second frequency are within the range of about 900 MHz to about 930 MHz or in the range of about 2.4 to about 2.5 GHz and the first frequency and the second frequency are different.

A method of providing a plasma, the method comprising:

• providing first microwave power from a first microwave generator to a first end of a powered electrode and a second microwave power from a second microwave generator to a second end of the powered electrode, the first microwave power and the second microwave power operating at frequencies in the range of about 900 MHz to about 930 MHz or in the range of about 2.4 to about 2.5 GHZ, the powered electrode enclosed in a dielectric with a ground electrode on a first side of the powered electrode, wherein the plasma is formed adjacent the dielectric on a second side of the powered electrode different from the first side, the plasma source assembly comprising:
• the powered electrode having a first end and a second end defining the length and having an axis extending along the length of the powered electrode, the powered electrode having a width;
• a ground electrode on a first side of the powered electrode, the ground electrode spaced from the powered electrode by a distance so that the powered electrode is suspended within a dielectric comprising one or more of air, vacuum or inert gas;
• and
• a first feed electrically coupled to the powered electrode and a second feed electrically coupled to the powered electrode, the first feed electrically coupled with a first microwave generator, the second feed electrically coupled with a dummy load.