| Diameter | 4“
| 5”
| 6“
| 8”
|
Device Layer | Dopant | Boron, Phos, Arsenic, Antimony, Undoped |
Orientation
| <100>, <111> |
| Type | SIMOX, BESOI, Simbond, Smart-cut |
Resistivity
| 0.001-20000 Ohm-cm |
| Thickness (um) | 0.2-150 |
| The Uniformity | <5% |
BOX Layer | Thickness (um) | 0.4-3
|
| Uniformity | <2.5% |
Substrate | Orientation
| <100>, <111> |
| Type/Dopant | P Type/Boron , N Type/Phos, N Type/As, N Type/Sb |
| Thickness (um) | 300-725
|
| Resistivity | 0.001-20000 Ohm-cm |
| Surface Finished | P/P, P/E
|
Particle
| <10@.0.3um |
SOI Advantages:
The SOI wafer structure has several important advantages over CZ bulk or epitaxial starting wafer architectures. SOI wafers potentially offer “perfect”
transistor isolation (lower leakage), tighter transistor packing density (higher transistor count/higher IC function at the same lithographic resolution), reduced
parasitic drain capacitance (faster circuit performance and lower power consumption), and simplified processing relative to bulk or epitaxial silicon
wafers. Due to these advantages, SOI wafers appear ideal for leading edge integrated circuits with high speed, high transistor count, low voltage/low
power operation, and battery operated systems requirements, such as portable logic or microprocessor ICs.
Currently there are three useful approaches for making SOI wafers. They are:
1. Silicon-On-Sapphire (SOS): The insulating substrate for SOS wafers is sapphire (i.e., very pure aluminum oxide〔Al2 O3 〕.
2. Separation by IMplanted OXygen (SIMOX): The insulator for SIMOX wafers is silicondioxide. A widely used approach to manufacture SOI wafers is that of SIMOX.Although SIMOX wafers can be obtained from several commercial suppliers, they arestill significantly more costly than bulk or epi wafers. The SIMOX technology is based on the used of very high dose oxygen ion implantation to produce subsurface layers of silicon dioxide.
3. Wafer Bonding (WB): The insulator for WB wafers is silicon dioxide. Another populartechnology for producing SOI wafers is WB. WB is a simple concept. Basically two oxidized Si wafers (or one oxidized wafer and one bare wafer) are fused together, face-to face, through a furnace process. Then most of the silicon from one of the wafers is removed and the device is built into the remaining silicon over the now-buriedoxide. Unlike SIMOX, the wafer bonding technique can form BOX layers up to 50um.A recent method, called Smart Cut, allows the sacrificial wafer to be reused and only one wafer is required to make a bonded SOI substrate. This one-wafer technology is termed Unibond.
