Selective etching and formation of xenon difluoride
View Patent ↗This invention relates to a process for selective removal of materials, such as: silicon, molybdenum, tungsten, titanium, zirconium, hafnium, vanadium, tantalum, niobium, boron, phosphorus, germanium, arsenic, and mixtures thereof, from silicon dioxide, silicon nitride, nickel, aluminum, TiNi alloy, photoresist, phosphosilicate glass, boron phosphosilicate glass, polyimides, gold, copper, platinum, chromium, aluminum oxide, silicon carbide and mixtures thereof. The process is related to the important applications in the cleaning or etching process for semiconductor deposition chambers and semiconductor tools, devices in a micro electro mechanical system (MEMS), and ion implantation systems. Methods of forming XeF 2 by reacting Xe with a fluorine containing chemical are also provided, where the fluorine containing chemical is selected from the group consisting of F 2 , NF 3 , C 2 F 6 , CF 4 , C 3 F 8 , SF 6 , a plasma containing F atoms generated from an upstream plasma generator and mixtures thereof.
1. A process for selective etching of a first material to a second material, comprising:
providing a structure containing the first material and the second material in a chamber;
providing an etchant gas to the chamber; wherein the etchant gas comprising of an inert gas, xenon(Xe) gas, and a fluorine containing chemical;
contacting the structure with the etchant gas and selectively converting the first material to a volatile species; and removing the volatile species from the chamber;
wherein the first material is silicon, and the second material is silicon dioxide, and etch ratio of the first material to the second material from 30 to 250;
wherein the pressure in the chamber is from 0.1 to 10 Torr and the mole ratio of Xe to fluorine containing chemical is from 1:10 to 10:1.
2. The process of claim 1 wherein the fluorine containing chemical is selected from the group consisting of F 2 , NF 3 , C 2 F 6 , CF 4 , C 3 F 8 , SF 6 , a plasma containing F atoms generated from an upstream plasma generator, and mixtures thereof.
3. The process of claim 1 wherein the fluorine containing chemical is a plasma containing F atoms generated from an upstream plasma generator.
4. The process of claim 1 wherein the inert gas is selected from the group consisting of Xe, Ar, He and mixtures thereof.
5. The process of claim 1 wherein the chamber contains a remote plasma generator.
6. The process of claim 1 wherein the temperature in the chamber is from ambient temperature to 500° C.
7. The process of claim 1 wherein the structure is a semiconductor device or a semiconductor processing chamber.
8. The process of claim 1 wherein the structure is a micro electro mechanical device.
9. The process of claim 1 wherein the structure is an ion implanter tool in an ion implantation system.