P type G12 Silicon Wafer

N-type  VS. P-type Silicon Wafer

    A p-type wafer is usually doped with Boron, although Gallium can also be used (rare). P+ wafers are heavily doped and typically have resistances of <1 Ohm/cm². P+ wafers are often used for Epi substrates. P- wafers are lightly doped with typical resistances of >1 Ohm/cm². The most common crystal orientations for P-type wafers are {100} and {111}.

    N-type wafers are doped with Phosphorus, Antimony, or Arsenic. N+ wafers are heavily doped with resistances <1 Ohm/cm². N- wafers are lightly doped with resistances >1 Ohm/cm². Resistivity is very important to good electronic devices and for growing uniform thermal oxides. High resistivity silicon can only be produced using the Float Zone (FZ) crystal growth method, which does not use a crucible during crystal growth. The Czochralski (CZ) method uses a quartz crucible during crystal growth, and oxygen from the crucible unintentionally dopes the material. The oxygen dopant behaves as an n-type impurity and impedes high resistivity. Low resistivity n-type material is achieved using Arsenic doping.

                     Standards Used to Measure Wafer Quality

1.Cleanliness

     1. Light point defects (LPDs) - Unwanted particles on surface of wafer.

    2. Particles measured by total number found acrossf a certain area of wafer. Some edge exclusions are applied.

2.Planarity

1. Total thickness variation (TTV) — Absolute difference in thickness between the thickest and thinnest parts of wafer. A typical value on a 8" wafer would be less than 15 um.
2.  Warp - The difference between minimum and maximum values of the wafer surface measured from a reference plane (usually the backside of the wafer). Deviations include both concave and convex variations. Warp is a bulk property. A good warp number on an 8" wafer is less than 20 um.

3.Global Total Indicated Reading (GTIR) — Maximum peak to valley deviation of a wafer from a given reference plane (often the backside of the wafer).

4.Site TIR - similar to GTIR except on smaller sites on wafer. Site TIR can be a parameter of greater importance then global TIR when resolving submicron geometries. 

5.Bow - Concavity or deformation of the wafer measured from the center independent of any thickness variation. Bow is a bulk property. Good bow on a 8" prime wafer is less than 30 um

Geometric parameters

All data contained in this datasheet is subject to change without notice.