JPWO2020257160A5 - - Google Patents

Claims (20)

A method of processing a substrate, comprising:
providing a substrate comprising a silicon oxide film and a silicon nitride film ;
a1 ) exposing the substrate to a first gas that forms a first layer on the silicon oxide film and a second layer on the silicon nitride film , the first gas comprising: , boron, aluminum, or both boron and aluminum;
a2 ) reacting with the first layer to form a first nitride layer on the silicon oxide film and reacting with the second layer to form a second nitride layer on the silicon nitride film ; exposing the substrate to a nitrogen-containing gas, wherein the thickness of the second nitride layer is greater than the thickness of the first nitride layer;
a3 ) an etching gas for etching the first nitride layer and the silicon oxide film ,
exposing the substrate , wherein the second nitride layer protects the silicon nitride film from being etched by the etching gas;
A method, including 2. The method of claim 1, further comprising repeating steps a1) and a2) at least once before performing step a3). 2. The method of claim 1, further comprising repeating steps a1), a2), and a3) at least once to further etch the silicon oxide film . Clause 1, further comprising: a0 ) exposing the substrate to an _H2 containing gas that terminates the silicon oxide film with -OH surface species and the silicon nitride film with -NH _x surface species. The method described in . 5. The method of claim 4, further comprising repeating a0), a1), a2), and a3) at least once to further etch the silicon oxide film . 5. The method of claim 4, further comprising repeating a1), a2), and a3) at least once to further etch the silicon oxide film . 2. The method of claim 1, wherein the first gas comprises borohydride, borohalide, an organoaluminum compound, aluminum hydride, aluminum chloride, or combinations thereof. 2. The method of claim 1, wherein the first gas is selected from the group consisting of _BH3 , _BCl3 , _BF3 , Al( _CH3 ) ₃ , _AlH3 , _AlCl3 , and combinations thereof. 2. The method of claim 1, wherein the nitrogen-containing gas is selected from the group consisting of nitrogen hydrides, nitrogen halides, _N2 , and combinations thereof. 2. The method of claim 1, wherein the nitrogen-containing gas is selected from the group consisting _{of NH3} , _N2H4 , _NCl3 , _N2 , and combinations thereof. 2. The method of claim 1, wherein the etching gas comprises a fluorocarbon gas, a hydrofluorocarbon gas, a hydrochlorocarbon gas, a hydrochlorofluorocarbon gas, or a combination thereof. _The etching gas is _CF4 , _CF2Cl2 , _CH2F2 , _{CH4 , CH3F , CHF3, C4H6 , C2H4 , C3H6 , CH2Cl2 , CH3. 2.} The method of claim 1 selected from the group consisting of Cl, CHCl2 , _CH2ClF , _CHCl2F , and combinations thereof. providing a substrate comprising a silicon oxide film and a silicon nitride film ;
a1 ) exposing the substrate to a BCl3 gas that _forms a first _BCl3 layer on the silicon oxide film and a second _BCl3 layer on the silicon nitride film;
a2 ) reacting with said first _BCl3 layer to form a first boron nitride layer on said silicon oxide film and reacting with said second _BCl3 layer to form a second boron nitride layer on said silicon nitride film ; exposing the substrate to _NH3 gas forming a boron nitride layer, wherein the thickness of the second boron nitride layer is greater than the thickness of the first boron nitride layer;
a3 ) exposing the substrate to a plasma-enhanced _CF4 gas that etches the first boron nitride layer and the silicon oxide film , wherein the second boron nitride layer is etched by the plasma-enhanced CF4 _gas ; protecting the silicon nitride film from etching by
A method of processing a substrate , comprising: 14. The method of claim 13, further comprising repeating steps a1) and a2) at least once before performing step a3). 14. The method of claim 13, further comprising repeating a1), a2), and a3) at least once to further etch the silicon oxide film . a0 ) further comprising exposing the substrate to an H2 containing gas that terminates the silicon oxide film with —OH surface species _and the silicon nitride film with —NH _x surface species. 13. The method according to 13. 17. The method of claim 16, further comprising repeating a0), a1), a2), and a3) at least once to further etch the silicon oxide film . 17. The method of claim 16, further comprising repeating a1), a2), and a3) at least once to further etch the silicon oxide film . providing a substrate comprising a silicon oxide film and a silicon nitride film ;
a1 ) exposing the substrate to a boron-containing gas that forms a first boron-containing layer on the silicon oxide film and a second boron-containing layer on the silicon nitride film ;
a2) reacting with the first boron-containing layer to form a first boron nitride layer on the silicon oxide film and reacting with the second boron-containing layer to form a second nitride on the silicon nitride film; exposing the substrate to a nitrogen-containing gas that forms a boron layer , wherein the thickness of the second boron nitride layer is greater than the thickness of the first boron nitride layer;
a3) exposing the substrate to an etching gas that etches the first boron nitride layer and the silicon oxide film , wherein the second boron nitride layer is removed from the silicon nitride film by etching with the etching gas; a step of protecting the
A method of processing a substrate , comprising: The boron-containing gas is selected from the group consisting of _BH3 , _BCl3 , _BF3 , and combinations _thereof , and the nitrogen-containing gas is _NH3 , _N2H4 , _NCl3 , _N2 , and combinations thereof. wherein said etching _gas is selected from _the group consisting _{of CF4} , _CF2Cl2 , _CH2F2 , _CH4 , _CH3F , _{CHF3 , C4H6} , _{C2H4 , C3H6 ,} 20. The method of claim 19 selected from _the group consisting of _CH2Cl2 , _CH3Cl , _CH3Cl , _CH2ClF , _CHCl2F , and combinations thereof.