Morphology of resist mask prior to etching
Embodiments provide a patterning process. A photoresist layer is patterned. At least portions of the photoresist layer are converted from an organic material to an inorganic material by a deposition process of a metal oxide. All or some of the patterned photoresist layer may be converted to a carbon-metal-oxide. A metal oxide crust may be formed over the patterned photoresist layer. After conversion, the patterned photoresist layer is used as an etch mask to etch an underlying layer.
1. A method, comprising:
patterning a photoresist layer to form a mask layer, the mask layer comprising an organic material, the mask layer disposed over a first layer;
converting a portion of the mask layer to an inorganic material, the inorganic material disposed on horizontal surfaces and vertical surfaces of the mask layer; and
etching the first layer using the inorganic material on the horizontal surfaces and the vertical surfaces of the mask layer as an etch mask.
2. The method of claim 1 , further comprising:
before converting the portion of the mask layer, performing a de-scum process, the de-scum process removing material from sidewall portions of the mask layer and removing material from exposed portions of the first layer.
3. The method of claim 1 , further comprising:
before converting the portion of the mask layer, performing a trim process, the trim process removing material from sidewall surfaces and upper surfaces of the mask layer.
4. The method of claim 1 , wherein converting the portion of the mask layer comprises:
depositing a metal oxide into the mask layer by an atomic layer deposition (ALD) process.
5. The method of claim 1 , wherein converting the portion of the mask layer comprises:
altering the mask layer to convert the mask layer to a carbon-metal-oxide material.
6. The method of claim 1 , wherein converting the portion of the mask layer comprises:
forming a metal oxide crust over the mask layer.
7. The method of claim 6 , further comprising:
forming a uniform crosslink of a carbon-metal-oxide at an interface of the metal oxide crust and the mask layer.
8. The method of claim 1 , wherein converting the portion of the mask layer comprises:
forming a carbon-metal-oxide crust at surfaces of the mask layer.
9. A method, comprising:
forming a photoresist layer over a target layer;
patterning the photoresist layer to form a mask, the mask comprising an organic material, portions of an underlayer directly beneath the mask exposed by the patterning;
applying a metal containing first precursor to the mask, the metal containing first precursor reacting with the mask without depositing on the underlayer; and
applying an oxygen containing second precursor to the mask, wherein following applying the first precursor and second precursor, the mask comprises an inorganic material.
10. The method of claim 9 , wherein the first precursor comprises:
trimethylaluminum (TMA, Al(CH 3 ) 3 ), diethylzinc (DEZ), tetrakis (dimethylamino) titanium (TDMAT), titanium isopropoxide (TTIP), TiCl 4 , bis(tertiary-butyl-amino) silane (BTBAS), bis(diethylamino)silane (BDEAS), tris(dimethylamino)silane (3DMAS), tetrakis(dimethylamido)zirconium (Zr(NMe 2 ) 4 ), zirconium tetrachloride (ZrCl 4 ), or tetrakis-dimethyl-amine tin (TDMASn).
11. The method of claim 10 , wherein the second precursor comprises H 2 O, O 2 , O 3 , or H 2 O 2 .
12. The method of claim 9 , further comprising:
prior to applying the first precursor, performing a de-scum process on the mask.
13. The method of claim 9 , further comprising:
prior to applying the first precursor, performing a trim process on the mask.
14. The method of claim 9 , further comprising:
forming a metal oxide crust over surfaces of the mask.
15. The method of claim 14 , further comprising:
forming a crosslink between the metal oxide crust and an organic portion of the mask.
16. The method of claim 9 , wherein following applying the first precursor and the second precursor, surfaces of the mask comprise a carbon-metal-oxide.
17. A method comprising:
forming a patterned etch mask over a target layer;
introducing an inorganic material to the etch mask;
etching the target layer, using the inorganic material to protect the etch mask during etching one or more layers between the etch mask and the target layer; and
forming conductive features in the target layer.
18. The method of claim 17 , wherein introducing the inorganic material to the etch mask comprises:
depositing a metal oxide into the etch mask; and
transforming carbon-oxygen bonds of the etch mask into carbon-metal-oxygen bonds.
19. The method of claim 17 , a portion of the etch mask including inorganic material comprises an entire thickness of the etch mask.
20. The method of claim 17 , wherein a portion of the etch mask including inorganic material includes surfaces of the etch mask, wherein a portion of the etch mask underlying the inorganic material has no inorganic material.