Deposition from liquid sources
A liquid injector is used to vaporize and inject a silicon precursor into a process chamber to form silicon-containing layers during a semiconductor fabrication process. The injector is connected to a source of silicon precursor, which preferably comprises liquid trisilane in a mixture with one or more dopant precursors. The mixture is metered as a liquid and delivered to the injector, where it is then vaporized and injected into the process chamber.
1. A method for semiconductor processing, comprising:
exposing a liquid silicon precursor to a hot ambient to convert the liquid silicon precursor into a precursor gas, the liquid silicon precursor comprising trisilane; and
flowing the precursor gas through a process chamber to deposit a silicon-containing film on a semiconductor substrate in the process chamber,
wherein a temperature of the hot ambient is greater than a boiling point of trisilane under processing conditions at a location where converting a liquid silicon precursor occurs, and the liquid silicon precursor is converted into the precursor gas before entry of the liquid silicon precursor into the process chamber;
wherein converting the liquid silicon precursor into the precursor gas comprises flowing liquid silicon precursor through a liquid injector, wherein the hot ambient is a surface of the liquid injector.
2. The method of claim 1 , wherein the process chamber is a single substrate process chamber.
3. The method of claim 1 , further comprising flowing a gaseous precursor though the liquid injector and into the process chamber.
4. The method of claim 1 , wherein the liquid silicon precursor comprises a dopant.
5. The method of claim 4 , wherein the dopant has a boiling point within about 60° C. of a boiling point of the liquid silicon precursor under process conditions.
6. The method of claim 5 , wherein the dopant has a boiling point within about 40° C. of a boiling point of the liquid silicon precursor under process conditions.
7. A method for semiconductor processing, comprising:
exposing a liquid silicon precursor to a hot ambient to convert the liquid silicon precursor into a precursor gas, the liquid silicon precursor comprising trisilane; and
flowing the precursor gas though a process chamber to deposit a silicon-containing film on a semiconductor substrate in the process chamber,
wherein a temperature of the hot ambient is greater than a boiling point of trisilane under processing conditions at a location where converting a liquid silicon precursor occurs, and the liquid silicon precursor is converted into the precursor gas before entry of the liquid silicon precursor into the process chamber;
wherein converting the liquid silicon precursor into the precursor gas comprises flowing liquid silicon precursor though a liquid injector, wherein the hot ambient is a porous matrix for receiving the liquid silicon precursor in the liquid injector.
8. A method for semiconductor processing, comprising:
exposing a pre-metered amount of a liquid silicon precursor mixture to a hot ambient to convert the liquid silicon precursor mixture into a precursor gas, the liquid silicon precursor mixture comprises trisilane and a dopant;
flowing the precursor gas though a process chamber to deposit a silicon-containing film on a semiconductor substrate in the process chamber,
wherein a temperature of the hot ambient is greater than a boiling point of trisilane under processing conditions at a location where converting a liquid silicon precursor mixture occurs; and
wherein the dopant has the chemical formula (H 3 Si) 3−x MH x , where x=1-3 and M=As, P, or B.
9. The method of claim 8 , wherein x=3 and M=P or As.
10. The method of claim 8 , wherein the dopant has a boiling point within about 60° C. of a boiling point of the liquid silicon precursor under process conditions.
11. The method of claim 10 , wherein the dopant has a boiling point within about 40°C. of a boiling point of the liquid silicon precursor under process conditions.