Oxide quality differentiation
Exemplary methods and systems of semiconductor processing may include etching a portion of a silicon-containing material from a substrate disposed within a processing region of a semiconductor processing chamber. Methods may include forming a low quality oxide within one or more of the recesses, where the low quality oxide and a silicon-containing material each contain an exposed surface. Methods include contacting the low quality oxide and the high quality semiconductor material with a passivating agent selective to a surface defect of the low quality oxide. Methods include contacting the substrate with an etching agent and/or a cleaning agent, where the contacting with the cleaning agent removes the high quality semiconductor material at an equal or faster rate than the low quality oxide.
1 . A semiconductor processing method comprising:
etching a portion of a silicon-containing material from a substrate disposed within a processing region of a semiconductor processing chamber, forming one or more recesses;
forming a low quality oxide within one or more of the recesses, wherein the low quality oxide and a silicon-containing material each comprise an exposed surface, and wherein the low quality oxide is a film or layer comprising an interface defect density (D it ) of greater than or about 10 12 cm −2 eV −1 , a leakage current of greater than or about 4×10 −9 A/cm 2 , and/or a surface hydroxyl content of greater than or about 1 μmol/m 2 ;
contacting the low quality oxide and the silicon-containing material with a passivating agent, forming a passivation layer on the low quality oxide; and
contacting the low quality oxide and the silicon-containing material with an etching agent and/or a cleaning agent, wherein the contacting with the cleaning agent removes the silicon-containing material at an equal or faster rate than the low quality oxide.
2 . The semiconductor processing method of claim 1 , wherein the passivating agent comprises an organosilane.
3 . The semiconductor processing method of claim 2 , wherein the organosilane comprises a vinyl silane.
4 . The semiconductor processing method of claim 3 , wherein the vinyl silane comprises vinyl silane, trimethylvinylsilane (TMVS), vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy) silane, vinyltrisisopropoxysilane, vinyltris(tert-butylperoxy) silane, vinyldimethylchlorosilane, vinyldimethylethoxysilane, vinylmethyldichlorosilane, vinylmethyldimethoxysilane, vinylmethyldiethoxysilane, methylvinyldi (n-methylacetylamido) silane, methylvinyldi (5-caprolactam)silane, bis(methyldichlorosilyl) ethane, and combinations thereof.
5 . The semiconductor processing method of claim 1 , wherein contacting the low quality oxide with the passivating agent comprises a silylation process.
6 . The semiconductor processing method of claim 1 , wherein the low quality oxide comprises a surface hydroxyl content of greater than or about 4 μmol/m 2 .
7 . The semiconductor processing method of claim 6 , wherein the low quality oxide comprise a chemical oxide of silicon.
8 . The semiconductor processing method of claim 1 , wherein the silicon-containing material comprises a surface hydroxyl content of less than or about 2 μmol/m 2 .
9 . The semiconductor processing method of claim 8 , wherein the silicon-containing material comprises polysilicon, silicon germanium, thermal silicon oxide or dioxide, native oxide, or a combination thereof.
10 . The semiconductor processing method claim 1 , wherein less than or about 20% of the low quality oxide is removed after contacting with the etching agent and/or cleaning agent.
11 . A method of forming a semiconductor structure comprising:
etching one or more recesses in a substrate disposed within a processing region of a semiconductor processing chamber, wherein a silicon-containing material extends into one or more recesses defined by alternating layers of material deposited on the substrate, and wherein an exposed surface of the silicon-containing material is characterized by a first hydroxyl concentration;
forming an oxide material in the one or more recesses, the oxide material having an exposed surface characterized by a second hydroxyl concentration, wherein the second hydroxyl concentration is greater than the first hydroxyl concentration;
exposing the processing region to a passivating agent, wherein the passivating agent undergoes a silylation process with one or more hydroxyl groups; and
contacting the substrate with an etching agent and/or a cleaning agent.
12 . The method of claim 11 , further comprising:
providing one or more etchant precursors to the processing region of the semiconductor processing chamber;
contacting the substrate with the one or more etchant precursors; and
etching a portion of the silicon-containing material from the substrate.
13 . The method of claim 11 , wherein the second hydroxyl concentration is greater than or about 50% higher than the first hydroxyl concentration.
14 . The method of claim 13 , wherein the second hydroxyl concentration is greater than or about 100% higher than the first hydroxyl concentration.
15 . The method of claim 11 , wherein the semiconductor structure comprises a gate all around structure.
16 . The method of claim 11 , further comprising:
exposing the substrate to ultraviolet (UV) radiation.
17 . A semiconductor processing method comprising:
contacting a semiconductor structure with a passivating agent, the semiconductor structure comprising
a substrate,
a silicon-containing material having an exposed surface characterized by a first hydroxyl concentration, and
an oxide material having an exposed surface characterized by a second hydroxyl concentration, wherein the second hydroxyl concentration is greater than the first hydroxyl concentration,
wherein the passivating agent undergoes a silylation process with one or more hydroxyl groups; and
contacting the substrate with an etching agent and/or a cleaning agent, removing a portion of the silicon-containing material.
18 . The semiconductor processing method of claim 17 , wherein less than or about 20% of the oxide material is removed after contacting with the etching agent and/or cleaning agent.
19 . The semiconductor processing method of claim 17 , wherein passivating occurs in a first chamber, and wherein the semiconductor structure is transferred to a second processing chamber prior to contacting the semiconductor structure with the etching agent and/or cleaning agent.
20 . The semiconductor processing method of claim 17 , wherein contacting the substrate with the etching agent and/or cleaning agent comprises a reactive ion etch, a selective oxide preclean, or a combination thereof.