Ä¢¹½Ó°ÊÓtv°æ Sources: BoronPlus and PhosPlus
Positives
- Simple, no complex equipment needed
- Startup is low cost
- No reactivation cycles like Boron Nitride
- Exhibit a minimum of water absorption
- Can be removed from diffusion boats. This results in long quartz ware life
- Extended time between tube deglaze operations, thus reducing furnace down time
- Controlled dopant release reduces silicon damage
- Any carrier gas can be used: nitrogen, argon, helium
- Oxygen insensitive. Deposition process can be optimized for best electrical results
- Uniform and clean deposition, regardless of wafer size
- Technical support by FAB experienced Ä¢¹½Ó°ÊÓtv°æ employees
- Comparable costs to other solid sources, like boron nitride
- Long use life
- During use, dimensional size remains the same due to its structural ceramic matrix
- Safe and easy to use. No health issue with handling of the sources
- High wafer load capacity, whole tube can be used
Negative
- Gases are less expensive, but this is offset by the cost savings of the other positives of Ä¢¹½Ó°ÊÓtv°æ’s sources
Dopant Gases
Diborane (B2H6), BBr3 (boron tribromide), Pockle or Phosphorous
Oxytrichloride (POCl3), Boron Trimethyl (B(CH3)3),
Boron Trichloride (BCL3)3), and Phosphine (PH3)
Positive
- Pure depositions
- Material costs are low
Negatives
- Glazing of furnace tube increases equipment down time
- Non-uniform deposition, which increasing problems with larger wafer size
- Gases required are toxic and problematic for health issues
- Gases required are corrosive
- Support and maintenance costs are higher due to the health and equipment requirements needed for the toxic and corrosive gases required
- Typically wafer load size is small, for good dopant uniform
Spin On Ä¢¹½Ó°ÊÓtv°æ
Positive
- Simple application, use of coating equipment
Negatives
- Can have high surface damage
- Very sensitive to trace impurities
- Startup cost involves specialized coat equipment
Ion Implant
Phosphine (PH3), Diborane (B2H6), Boron Trifluoride (BF3)
Positive
- Uniform doping
- Safe during implantation use
Negatives
-
- Dangerous gases must be used for implantation, health and safety requirements
- Startup cost is very capital intensive
- High maintenance cost, part costs, and down time
- Implantation has silicon channeling which can negatively impact electrical performance and final yields
- Silicon damage results from the implantation and additional processing is needed for annealing this damage
Planar Boron Nitride (BN) Solid Sources
Positives
- Uniform doping
- Safe
- Simple to use
Negatives
- Impurities are deposited
- Sources are very hygroscopic (absorbs moisture quickly). This causes resistivity consistency issues.
- High silicon damage occurs due to high deposition rate.
- Users observe source warpage during use.
- Sources thin during use. This causes deposition uniformity problems as they lean in the boat during use.