Abstract: A gas distributing system and a method of operating the distributing system is provided. After setting a few control valve parameters, the gas distributing system automatically adjusts the distribution of plasma gas inside a wafer processing chamber during a dry etching or a film deposition process so that uniform single wafer is produced. First, a main gas conduit is redirected into two separate gas conduit inside a gas separator. One conduit connects with a gas nozzle near the central region of an upper electrode panel distributor and the other conduit connects with a gas nozzle near the peripheral region of the upper electrode panel distributor. An O-ring between the central region and the peripheral region prevents any mixing of gas from the nozzles in these two regions. Gas distribution inside the reaction chamber can be changed to meet the need of different processing conditions by adjusting the flow control valves mounted on the two conduits.

Abstract: A method for forming shallow trench isolations includes the steps of defining a wafer substrate, forming a silicon dioxide insulating layer on the substrate, depositing a silicon nitride layer on the silicon dioxide insulating layer, and forming at least one trench in the substrate through the silicon dioxide and silicon nitride layers. The method also includes the steps of depositing a silicon dioxide layer over the silicon nitride layer and in the trench, removing the silicon dioxide layer deposited over the silicon nitride layer, anisotropically etching the silicon dioxide layer to produce silicon dioxide sidewalls in the trench contiguous with the silicon nitride layer, isotropically etching to remove the sidewalls and removing the silicon nitride layer.

Abstract: A method for forming shallow trench isolations includes the steps of defining a wafer substrate, forming a silicon dioxide insulating layer on the substrate, depositing a silicon nitride layer on the silicon dioxide insulating layer, and forming at least one trench in the substrate through the silicon dioxide and silicon nitride layers. The method also includes the steps of depositing a silicon dioxide layer over the silicon nitride layer and in the trench, removing the silicon dioxide layer deposited over the silicon nitride layer, anisotropically etching the silicon dioxide layer to produce silicon dioxide sidewalls in the trench contiguous with the silicon nitride layer, isotropically etching to remove the sidewalls and removing the silicon nitride layer.

Abstract: A method for cleaning a polymer in a trench produced by a dry anisotropic etching process is disclosed. The method includes steps of introducing a gas into a trench for reacting with the polymer to form a volatile substance and removing the remaining polymer in the trench by a wet etching process. The gas is preferably a gaseous hydrofluoric acid to clean the polymer. Because the gas can enter the small hole of the deep trench easily, this method can completely remove the polymer in the trench.

Abstract: A method for forming shallow trench isolations includes the steps of defining a wafer substrate, forming a silicon dioxide insulating layer on the substrate, depositing a silicon nitride layer on the silicon dioxide insulating layer, and forming at least one trench in the substrate through the silicon dioxide and silicon nitride layers. The method also includes the steps of depositing a silicon dioxide layer over the silicon nitride layer and in the trench, removing the silicon dioxide layer deposited over the silicon nitride layer, anisotropically etching the silicon dioxide layer to produce silicon dioxide sidewalls in the trench contiguous with the silicon nitride layer, isotropically etching to remove the sidewalls and removing the silicon nitride layer.

Abstract: A semiconductor fabrication chamber is disclosed which contains (a) a main chamber; (b) a baffle member separating the main chamber into a first chamber and a second chamber, (c)a vacuum pump to pump gas through the main chamber; and (d) a computer. The first chamber contains a gas inlet, a metering device, and a supporting member to support a wafer to be fabricated, and the second chamber contains a gas outlet and a first pressure gauge. The baffle member contains at least one adjustable opening which is controllable by the computer. Prior to a fabrication process, such as plasma etching, a pressure difference between the first pressure gauge and a temporary pressure gauge installed inside the second chamber is calculated and compared against a standard value, and the computer will adjust the opening of the baffle plate so as to minimize such pressure difference, which is related to the deposition of particulate matters on the opening.

Abstract: A method of forming metal contact holes during semiconductor fabrication. The method includes three major steps to form the metal contact holes; a wet isotropic etching process for forming a first recess portion, a dry isotropic etching process for extending the first recess portion into a second recess portion, and a dry anisotropic etching process for forming a third recess portion beneath the second recess portion. The second recess portion and the third recess portion in combination constitute the metal contact hole. The lateral extent of the second recess portion, which in part affects subsequent deposition of metal in the contact hole and thus the step coverage effect of the metal connection, can be controlled by limiting the time of the dry isotropic etching process.