	US 12,068,385 B2
	Oxidation to mitigate dry etch and/or wet etch fluorine residue
U-Ting Chiu, Hsinchu (TW); Chun-Cheng Chou, Taichung (TW); Chi-Shin Wang, Hsinchu (TW); Chun-Neng Lin, Hsinchu (TW); and Ming-Hsi Yeh, Hsinchu (TW)
Assigned to Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed on Aug. 27, 2021, as Appl. No. 17/446,218.
Claims priority of provisional application 63/176,032, filed on Apr. 16, 2021.
Prior Publication US 2022/0336615 A1, Oct. 20, 2022
Int. Cl. H01L 29/45 (2006.01); H01L 21/311 (2006.01); H01L 21/3213 (2006.01); H01L 21/768 (2006.01); H01L 23/528 (2006.01); H01L 29/417 (2006.01)

CPC H01L 29/45 (2013.01) [H01L 21/31116 (2013.01); H01L 21/32134 (2013.01); H01L 21/76877 (2013.01); H01L 23/528 (2013.01); H01L 29/41725 (2013.01)]

20 Claims

1. A method, comprising:

performing a dry etching process using a fluorine (F) plasma to form a recess within an oxide layer that is above a source/drain contact,

wherein the dry etching process results in fluorine residue in the recess;

performing an oxidation process to remove the fluorine residue from the recess after the dry etching process;

performing a cleaning process on the recess using a solvent after removing the fluorine residue from the recess; and

forming a conductive structure within the recess after performing the cleaning process.

6. A method, comprising:

performing a first wet etching process using a fluorine (F) plasma to form a recess within a source/drain contact that is between an oxide layer and an epilayer,

wherein the first wet etching process results in first fluorine residue in the recess;

performing a first oxidation process to remove the first fluorine residue from the recess;

performing a second wet etching process using the fluorine (F) plasma to increase a depth and a width of the recess after removing the first fluorine residue from the recess,

wherein the second wet etching process results in second fluorine residue in the recess;

performing a second oxidation process to remove the second fluorine residue from the recess;

performing a cleaning process on the recess using a solvent after removing the second fluorine residue from the recess; and

forming a conductive structure within the recess after the cleaning process.

13. A method, comprising:

performing a first etching process using a fluorine (F) plasma to form a recess within an oxide layer that is above a source/drain contact,

wherein the first etching process results in fluorine residue in the recess;

performing a first oxidation process to remove the fluorine residue from the recess;

performing a second etching process using the fluorine (F) plasma to increase a depth and a width of the recess after removing the fluorine residue from the recess,

wherein the second etching process results in additional fluorine residue in the recess;

performing a second oxidation process to remove the additional fluorine residue from the recess;

performing a cleaning process on the recess using a solvent after removing the additional fluorine residue from the recess; and

forming a conductive structure within the recess after the cleaning process.