Patent ID: 9404181
Filing Date: 2016-08-02
CPC Classification: C23C

Claim Text:
1. A plasma enhanced atomic layer deposition (PEALD) system, which is used to form thin films on substrates, comprising: a plasma chamber, which includes an outer quartz tubular unit and an inner quartz tubular unit, whose central axis is aligned with that of the outer quartz tubular unit, wherein plasma is generated in an annular space formed between the outer quartz tubular unit and the inner quartz tubular unit, and wherein a plasma outlet is formed at a lower end of the plasma chamber to allow the exit of the plasma generated in the annular space; a processing chamber, wherein a substrate is placed in the processing chamber, and wherein the processing chamber has a circular precursor inlet unit and a circular nitrogen inlet unit and is in communication with the plasma outlet, and wherein a precursor is introduced through the circular precursor inlet unit and reacts with the substrate, and wherein the circular nitrogen inlet unit is provided over the circular precursor inlet unit to provide nitrogen flowing downwards to the circular precursor inlet unit; a first ring unit, disposed at a junction between the plasma chamber and the processing chamber, wherein a plurality of first through holes are circumferentially disposed in the first ring unit; a second ring unit, disposed under the first ring unit, wherein a plurality of second through holes are circumferentially disposed in the second ring unit and each of the second through holes has a diameter greater than that of each of the first through holes; and a control piece, disposed inside the processing chamber, wherein the control piece causes the second ring unit to rotate in a reciprocating manner with respect to the first ring unit so as to align and misalign the second through holes with the first through holes and hence to open and close a passage between the processing chamber and the plasma chamber, wherein when the second through holes align with the first through holes, the plasma generated in the plasma chamber may go through the plasma outlet, first through holes and second through holes to reach the processing chamber and act on the substrate and when the second through holes misalign with the first through holes, the plasma generated in the plasma chamber may not go through the second through holes to reach the processing chamber; wherein the circular nitrogen inlet unit is located inside the processing chamber to surround the first ring unit and the second ring unit in a same plane, and because the second through hole is larger than the first through hole, a plasma flow passing the second through hole has a gradually-increasing cross section until the plasma flow reaches the substrate, that is, the plasma passing the second through holes forms a plurality of upside-down funnel-shaped plasma bundles so that the plasma is more evenly distributed on the substrate.