Devices and methods for controlling wafer uniformity in plasma-based process

A device for plasma-based processes, comprising:

• a housing defining a process chamber, wherein the housing comprises:
• a gas inlet configured to receive a process gas, and
• a gas outlet configured to expel a processed gas;
• and
• a gas distribution plate (GDP) arranged in the process chamber and configured to distribute the process gas within the process chamber to achieve a silicon etching uniformity less than 10%, the GDP comprising:
• an annular body that extends laterally from an inner sidewall to an outer sidewall and consists of a first zone, a second zone and a third zone positioned within the annular body, wherein the first, second and third zones form the entirety of the annular body, wherein the third zone is bordered between the gas inlet and a first edge of the first zone, and the second zone is bordered between the gas inlet and a second edge of the first zone opposite the first edge of the first zone such that the first zone is disposed between the second and third zones, and wherein the first zone comprises seven holes that are filled such that no gas flows through the first zone, and wherein the first zone comprises approximately one-quarter of the annular body;
• a first plurality of holes extending through the third zone of the annular body from lower surface of the annular body toward an upper surface of the annular body, wherein each of the first plurality of holes have a circular cross section with a first diameter;
• and
• a second plurality of holes extending through the second zone of the annular body from a lower surface of the annular body toward an upper surface of the annular body, wherein each of the second plurality of holes have a circular cross section with a second diameter,
• wherein the first diameter of each of the first plurality of holes is in the range of 0.48 to 0.52 millimeters (mm) and the second diameter of each of the second plurality of holes is in the range of 0.4 to 0.46 mm, and
• wherein the first plurality of holes is smaller in number than that of the second plurality of holes.

A device for plasma-based processes, comprising:

• a housing defining a process chamber, wherein the housing comprises:
• a gas inlet configured to receive a process gas, and
• a gas outlet configured to expel a processed gas;
• and
• a gas distribution plate (GDP) arranged in the process chamber and configured to distribute the process gas within the process chamber to achieve a silicon etching uniformity less than a threshold, the GDP comprising:
• an annular body that extends laterally from an inner sidewall to an outer sidewall and consists of a first zone, a second zone and a third zone positioned within the annular body, wherein the first, second and third zones form the entirety of the annular body, wherein the third zone is bordered between the gas inlet and a first edge of the first zone, and the second zone is bordered between the gas inlet and a second edge of the first zone opposite the first edge of the first zone such that the first zone is disposed between the second and third zones, and wherein the first zone comprises a plurality of holes that are filled such that no gas flows through the first zone, and wherein the first zone comprises approximately one-quarter of the annular body;
• a first plurality of holes extending through the third zone of the annular body from lower surface of the annular body toward an upper surface of the annular body, wherein each of the first plurality of holes have a circular cross section with a first diameter;
• and
• a second plurality of holes extending through the second zone of the annular body from a lower surface of the annular body toward an upper surface of the annular body, wherein each of the second plurality of holes have a circular cross section with a second diameter, and
• wherein a minimum value of the first diameter of each of the first plurality of holes is greater than a maximum value of the second diameter of each of the second plurality of holes.