Method, system and apparatus for forming a metal sulfide layer
A method, system and apparatus are disclosed for depositing a threshold voltage shifting layer comprising an oxygen-free metal sulfide on a substrate, wherein the depositing further comprises, providing a substrate having a surface within a reaction chamber, a) providing an oxygen-free precursor comprising a metal to the reaction chamber to contact the surface, b) providing an oxygen-free, sulfur-containing reactant to the reaction chamber to contact the surface, c) purging the reaction chamber and repeating operations a), b) or c) or any combination thereof until the threshold voltage shifting layer of a predetermined thickness is deposited on the surface.
1 . A method comprising:
depositing a threshold voltage shifting layer comprising a metal sulfide on a substrate, wherein the depositing comprises:
a) providing a substrate having a surface within a reaction chamber;
b) providing an oxygen-free precursor comprising a metal to the reaction chamber to contact the surface;
c) providing an oxygen-free, sulfur-containing reactant compound to the reaction chamber to contact the surface;
d) purging the reaction chamber; and
repeating operations b), c) or d) or any combination thereof until the threshold voltage shifting layer of a predetermined thickness is deposited on the surface,
wherein the sulfur-containing reactant compound has a formula selected from:
(1) HS(CRR′)xSH, wherein R and R′ are independently selected from the group consisting of hydrogen (H), methyl (Me), ethyl (Et), n-propyl (nPr), and x is an integer from 1 to 12;
(2) S(SiRR'R″)2, wherein R, R′ and R″ are independently selected from the group consisting of H, Me, Et, nPr, isopropyl (iPr), tert-butyl (tBu), normal butyl (nBu), sec-butyl (sec-Bu), and iso-butyl (iso-Bu); or
(3) S2RR′, wherein R and R′ are independently selected from the group consisting of Me, Et, nPr, iPr, tBu, nBu, sec-Bu, and iso-Bu.
2 . The method of claim 1 , wherein the surface comprises an interlayer material and the threshold voltage shifting layer is deposited in a dipole first pattern directly onto the interlayer material surface.
3 . The method of claim 1 , wherein the surface comprises a high-k material and the threshold voltage shifting layer is deposited in a dipole last pattern directly onto the high-k material surface.
4 . The method of claim 1 , wherein the metal comprises titanium (Ti), zirconium (Zr), hafnium (Hf), tantalum (Ta), aluminum (Al), scandium (Sc), lutetium (Lu), yttrium (Y), magnesium (Mg), lanthanum (La), or strontium (Sr), or a combination thereof.
5 . The method of claim 1 , wherein the oxygen-free precursor is a metal cyclopentadienyl compound, and the metal comprises scandium (Sc), lutetium (Lu), yttrium (Y), magnesium (Mg), lanthanum (La), or strontium (Sr).
6 . The method of claim 1 , wherein the oxygen-free precursor is a metal alkylamido compound, and the metal comprises titanium (Ti), zirconium (Zr), hafnium (Hf), tantalum (Ta), or aluminum (Al).
7 . The method of claim 1 , wherein the oxygen-free precursor is a metal amidinate compound, and the metal comprises scandium (Sc), lutetium (Lu), yttrium (Y), magnesium (Mg), lanthanum (La), or strontium (Sr).
8 . The method of claim 7 , wherein the metal amidinate compound is of the formula (Formula 1):
wherein: M is a metal; R and R′ are independently any branched alkyl, unbranched alkyl, cyclic alkyl, or acyclic alkyl, or a combination thereof, containing from 1-10 carbon atoms; and R″ is hydrogen, dimethylamino, diethylamino, ethylmethylamino or an alkyl containing 1-6 carbon atoms.
9 . The method of claim 8 , wherein R and R′are independently selected from the group consisting of isopropyl, tert-butyl, sec-butyl, and tert-pentyl.
10 . The method of claim 8 , wherein in R″ is hydrogen or methyl.
11 . The method of claim 1 , wherein the sulfur-containing reactant compound is HS(CH2)2SH or HS(CH)3SH.
12 . The method of claim 1 , wherein the sulfur-containing reactant compound is S(SiMe3)2 or S(SiEt3)2.
13 . The method of claim 1 , wherein the sulfur-containing reactant compound is S2Me2, S2Et2 or S2(tBu)2.