Method and apparatus for wafer cleaning

An apparatus for wet processing the device side of individual wafers, comprising:

• an acoustic energy generator comprising a platter having a frontside and a backside, and a plurality of megasonic piezoelectric transducers attached to the backside of the platter;
• a wafer bracket for positioning a wafer having a device side and a non-device side over the acoustic energy generator, wherein the device side of the wafer is distal to the acoustic energy generator and the non-device side of the wafer is proximate to the acoustic energy generator, and the non-device side of the wafer is positioned substantially parallel to and over the platter front side so that a gap is formed between said wafer non-device side and said platter frontside, wherein the wafer bracket is rotatable relative to the platter, and wherein the plurality of megasonic piezoelectric transducers provide between 90-100% coverage of the wafer non-device side;
• a first liquid dispenser comprising a liquid feed port for flowing a first liquid between said acoustic energy generator and said wafer such that the first liquid fills the gap between the frontside of the platter and the non-device side of the wafer in order to transfer acoustic energy from the acoustic energy generator to the non-device side of the wafer;
• a second liquid dispenser comprising a nozzle for flowing a processing liquid from the second liquid dispenser and onto said device side of the wafer;
• wherein said transducers can apply megasonic energy to said platter, which transfers the megasonic energy to said liquid in said gap, which transfers to said non-device side of the wafer, which transfers to the device side of the wafer, and then, transfers the megasonic energy to the processing fluid on the device side of the wafer;
• and
• wherein the acoustic energy that can be transferred to the non-device side of the wafer can be transferred to the device side of the wafer having a frequency and intensity at the device side of the wafer to improve the cleaning performance of the processing liquid on the device side of the wafer, while also minimizing an associated risk of damage to devices on the wafer due to the acoustic energy acting on the device side of the wafer.

An apparatus for wet processing the device side of individual wafers, comprising:

• an acoustic energy generator comprising a platter having a frontside and a backside, and a plurality of megasonic piezoelectric transducers attached to the backside of the platter;
• a wafer bracket for positioning a wafer having a device side and a non-device side over the acoustic energy generator, wherein the device side of the wafer is distal to the acoustic energy generator and the non-device side of the wafer is proximate to the acoustic energy generator, and the non-device side of the wafer is positioned substantially parallel to and over the platter front side so that a gap is formed between said wafer non-device side and said platter frontside, wherein the wafer bracket is capable of rotation up to 6000 rpm relative to the platter;
• a first liquid dispenser comprising a liquid feed port for flowing a first liquid between said acoustic energy generator and said wafer such that the first liquid fills the gap between the frontside of the platter and the non-device side of the wafer in order to transfer acoustic energy from the acoustic energy generator to the non-device side of the wafer;
• a second liquid dispenser comprising a nozzle for flowing a processing liquid from the second liquid dispenser and onto said device side of the wafer;
• wherein said transducers can apply megasonic energy to said platter, which transfers the megasonic energy to said liquid in said gap, which transfers to said non-device side of the wafer, which transfers to the device side of the wafer, and then, transfers the megasonic energy to the processing fluid on the device side of the wafer;
• and
• wherein the acoustic energy that can be transferred to the non-device side of the wafer can be transferred to the device side of the wafer having a frequency and intensity at the device side of the wafer to improve the cleaning performance of the processing liquid on the device side of the wafer, while also minimizing an associated risk of damage to devices on the wafer due to the acoustic energy acting on the device side of the wafer.

An apparatus for wet processing the device side of individual wafers, comprising:

• an acoustic energy generator comprising a platter having a frontside and a backside, and a plurality of megasonic piezoelectric transducers attached to the backside of the platter;
• a wafer bracket for positioning a wafer having a device side and a non-device side over the acoustic energy generator, wherein the device side of the wafer is distal to the acoustic energy generator and the non-device side of the wafer is proximate to the acoustic energy generator, and the non-device side of the wafer is positioned substantially parallel to and over the platter front side so that a gap is formed between said wafer non-device side and said platter frontside, wherein the wafer bracket is rotatable relative to the platter, and wherein the plurality of megasonic piezoelectric transducers cover greater than 80% of the platter backside area;
• a first liquid dispenser comprising a liquid feed port for flowing a first liquid between said acoustic energy generator and said wafer such that the first liquid fills the gap between the frontside of the platter and the non-device side of the wafer in order to transfer acoustic energy from the acoustic energy generator to the non-device side of the wafer;
• a second liquid dispenser comprising a nozzle for flowing a processing liquid from the second liquid dispenser and onto said device side of the wafer;
• wherein said transducers can apply megasonic energy to said platter, which transfers the megasonic energy to said liquid in said gap, which transfers to said non-device side of the wafer, which transfers to the device side of the wafer, and then, transfers the megasonic energy to the processing fluid on the device side of the wafer;
• and
• wherein the acoustic energy that can be transferred to the non-device side of the wafer can be transferred to the device side of the wafer having a frequency and intensity at the device side of the wafer to improve the cleaning performance of the processing liquid on the device side of the wafer, while also minimizing an associated risk of damage to devices on the wafer due to the acoustic energy acting on the device side of the wafer.

An apparatus for wet processing a substrate comprising:

• a platter having a frontside and a backside;
• one or more acoustic wave transducers mounted on the platter backside;
• a bracket for positioning a substrate over the platter, the bracket rotatable relative to the platter;
• a first liquid dispenser for flowing a first liquid between the platter and the substrate;
• and
• a second liquid dispenser above the platter for flowing a processing liquid from the second liquid dispenser and onto the substrate.