Contact formation through low-tempearature epitaxial deposition in semiconductor devices
A semiconductor material layer is deposited on a p-type source/drain region of a p-type transistor device and an n-type source/drain region of an n-type transistor device. The p-type device transistor device and the n-type transistor device are formed on a substrate of a semiconductor device. The semiconductor device includes a trench formed through an inter-level dielectric layer. The inter-level dielectric layer is formed over the n-type transistor device and the p-type transistor device. The trench exposes the p-type source/drain region of the p-type transistor device and the n-type source/drain region of the n-type transistor device. An element is implanted in the semiconductor material layer to form an amorphous layer on p-type source drain region and the n-type source/drain region. The amorphous layer is annealed to form a first metastable alloy layer upon the p-type source/drain region and a second metastable alloy layer upon the n-type source/drain region.
1. A method for fabricating a semiconductor device comprising:
depositing a semiconductor material layer on a p-type source/drain region of a p-type transistor device and an n-type source/drain region of an n-type transistor device, the p-type transistor device and the n-type transistor device being formed on a substrate of a semiconductor device, the semiconductor device including a trench formed through an inter-level dielectric layer, the inter-level dielectric layer being formed over the n-type transistor device and the p-type transistor device, the trench exposing the p-type source/drain region of the p-type transistor device and exposing the n-type source/drain region of the n-type transistor device;
implanting an element in the semiconductor material layer to form an amorphous layer on the p-type source/drain region and the n-type source/drain region, wherein the implanting of the element to form the amorphous layer comprises implanting an electrically neutral element selected from one of silicon (Si), germanium (Ge), or noble gases; and
annealing the amorphous layer to form a first metastable alloy layer upon the p-type source/drain region and a second metastable alloy layer upon the n-type source/drain region.
2. The method of claim 1 , further comprising depositing at least one metal layer upon the p-type source/drain region and the n-type source/drain region.
3. The method of claim 2 , further comprising forming metal wires to the p-type source/drain region and the n-type source/drain region.
4. The method of claim 2 , further comprising annealing the first and the second metastable alloy layers and the metal layer to form a metal-semiconductor metallic compound at interfaces of the first and the second metastable alloy layers and the metal layer.
5. The method of claim 1 , wherein the semiconductor material layer comprises a low-temperature silicon (Si) layer of less than 5 nanometer thick deposited at temperature of less than 500 C.
6. The method of claim 1 , wherein the semiconductor material layer comprises a low-temperature silicon germanium (SiGe) layer of less than 10 nanometer thick deposited at temperatures of less than 500 C.
7. The method of claim 1 , wherein the annealing comprises a millisecond annealing at or above recrystallization temperature of amorphous layers.
8. The method of claim 1 , wherein the annealing comprises a nanosecond annealing at or above melting temperature of amorphous layers.
9. The method of claim 1 , wherein the implanting of the element to form the amorphous layer comprises of implanting a first dopant element of a first polarity, blocking the device of the first polarity by a block mask, and implanting a second dopant element of a second polarity into the device of the second polarity.
10. The method of claim 9 , further comprising etching an amorphous layer of the first polarity prior to implanting a dopant element of the second polarity.
11. The method of claim 9 , wherein the dopant element of the first polarity is selected from Gallium (Ga) or Boron (B) and the dopant element of the second polarity is selected from Phosphorus (P) or Arsenic (As).
12. The method of claim 11 , wherein an implanted dose of the dopant element of the second polarity is larger than an implanted dose of the dopant element of the first polarity.