Method of forming a metal nitride layer over exposed copper
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsYi-Lung Cheng, Wen-Kung Cheng, Sez-An Wu, Yi-Lung Wang, Shin-Chi Lin
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Abstract
A method of depositing a plasma enhanced CVD metal nitride layer over an exposed copper surface in a semiconductor wafer manufacturing process to improve the metal nitride layer adhesion and to reduce copper hillock formation including providing a process surface which is an exposed copper surface; preheating the process surface; plasma sputtering the exposed copper surface in-situ to remove copper oxides; and, depositing a metal nitride layer in-situ according to a plasma enhanced CVD process at a selected deposition pressure to reduce plasma ion bombardment energy transfer and to suppress-copper hillock formation.
Claims20
A method of depositing a plasma enhanced CVD metal nitride layer over an exposed copper surface in a semiconductor wafer manufacturing process to improve the metal nitride layer adhesion and to reduce copper hillock formation comprising the steps of:
- providing a process surface comprising an exposed copper surface;
- pre-heating the process surface;
- plasma sputtering the exposed copper surface in-situ to remove copper oxides;
- and,
- depositing a metal nitride layer in-situ according to a plasma enhanced CVD process at a selected deposition pressure to reduce plasma ion bombardment energy transfer and to suppress copper hillock formation.
A method of in-situ plasma sputtering and plasma enhanced CVD silicon nitride layer deposition over an exposed copper surface to reduce a thermal cycle budget and suppress copper hillock formation comprising the steps of:
- providing a semiconductor wafer having a process surface comprising an exposed copper surface;
- arranging the semiconductor wafer in thermal heat transfer relationship to maintain a pre-selected process surface temperature range;
- pre-heating the process surface to a temperature within the pre-selected process surface temperature range;
- plasma sputtering the exposed copper surface in-situ with an ammonia (NH3) containing plasma source gas to remove copper oxides;
- and,
- depositing a silicon nitride layer in-situ according to a plasma enhanced CVD process at a pressure of about 2.5 Torr to about 4.2 Torr to minimize localized surface heating thereby suppressing copper hillock formation.
A method of in-situ plasma sputtering and plasma enhanced CVD silicon nitride layer deposition over copper filled semiconductor features to reduce a thermal cycle budget and suppress copper hillock formation comprising the steps of:
- providing a semiconductor wafer having a process surface comprising copper filled features having an exposed copper surface;
- arranging the semiconductor wafer in thermal heat transfer relationship to maintain a pre-selected process surface temperature range;
- pre-heating the process surface to a temperature not greater than about 350° C. and a pressure not greater than about 4.2 Torr;
- plasma sputtering the exposed copper surface in-situ with an ammonia (NH3) containing plasma source gas to remove copper oxides at a pressure not greater than about 4.2 Torr;
- and,
- depositing a silicon nitride layer in-situ according to a plasma enhanced CVD process at a pressure of not greater than about 4.2 Torr to reduce a thermal cycle budget to suppress copper hillock formation.
Dependencies are inferred from the claim text.