Formation of low-temperature and high-temperature in-situ doped source and drain epitaxy using selective heating for wrap-around contact and vertically stacked device architectures
Techniques herein provide thermal processing solutions applicable to both existing FINFET applications, including wrap-around contacts, as well as 3D architectures such as transistor-on-transistor and gate-on-gate monolithic or heterogeneous CFET. Techniques include heating or annealing a first target material without heating or affecting performance of a second material or other materials. Techniques include using a first heating process to heat a substrate and materials provided thereon to a first temperature, and then using a wavelength/frequency tunable second heating process to increase temperature of the target material without increasing temperature of the second material or other materials.
1 . A method of fabricating a semiconductor device, comprising:
providing a substrate including a lower-tier first transistor device including a first source/drain material;
performing a first heating process on the substrate and the first transistor device to form a layer of first silicide material from the first source/drain material;
providing a second transistor device as an upper-tier transistor device vertically stacked above the lower-tier first transistor device on the substrate in a complementary field effect transistor (CFET) architecture including a second source/drain material, the first silicide material having a first silicide material absorption wavelength and the second source/drain material having a second source/drain material absorption wavelength, the first silicide material absorption wavelength being different from the second source/drain material absorption wavelength; and
performing a selective beating process on the substrate, the first transistor device with the first silicide material and the second transistor device using a selective wavelength based on the first silicide material absorption wavelength being different from the second source/drain material absorption wavelength, the selective beating process beating the second source/drain material without substantially beating the first silicide material by causing the second source/drain material to reach a first temperature based on the second source/drain material absorption wavelength substantially absorbing the selective wavelength of the selective heating process and the first silicide material to remain below a second temperature based on the first silicide material absorption wavelength minimally absorbing the selective wavelength of the selective heating process.
2 . The method of claim 1 , wherein heating the second source/drain material further comprises irradiating the second source/drain material with the selective wavelength having a first peak wavelength at a first intensity via the selective heating process.
3 . The method of claim 2 , further comprising adjusting the selective wavelength having the first peak wavelength of the selective heating process while performing the selective heating process on the substrate, the first transistor device with the first silicide material, and the second transistor device.
4 . The method of claim 3 , further comprising determining a dopant concentration in the second source/drain material, wherein the selective wavelength having the first peak wavelength of the selective heating process is adjusted based on the dopant concentration in the second source/drain material.
5 . The method of claim 2 , further comprising executing a deposition process after the performing the selective beating process.
6 . The method of claim 5 , further comprising repeating the steps of the performing the selective heating process and the executing the deposition process.
7 . The method of claim 6 , wherein the second temperature is 500° C.
8 . The method of claim 2 , wherein the performing the selective heating process follows a heating sequence including set points of the selective wavelength having the first peak wavelength at corresponding set points of the first intensity over a corresponding first set of time intervals.
9 . The method of claim 2 , wherein the first silicide material absorption wavelength of the first silicide material does not include the selective wavelength having the first peak wavelength.
10 . The method of claim 2 , wherein the selective heating process includes using a tunable microwave anneal system configured to emit at the first peak wavelength and the first intensity.
11 . The method of claim 10 , wherein a range for the first peak wavelength of the tunable microwave anneal system emission is 42 to 150 millimeters.
12 . The method of claim 2 , wherein the selective heating process includes using a tunable laser anneal system configured to emit at the selective wavelength having the first peak wavelength and the first intensity.
13 . The method of claim 12 , wherein a range for the selective wavelength having the first peak wavelength of the tunable laser anneal system is 700 nm to 2,000 nm.
14 . The method of claim 2 , wherein the second source/drain material is silicon or silicon germanium.