Lithium Tantalate - Free of Pyro-Electric Discharge

Lithium Tantalate Wafers Free of Pyro-Electric Discharge

  • High ability to neutralise pyro-electric charges. Black Lithium Tantalate wafers neutralise electrical charges even if the electrical potential occurs instantaneously
  • Black Lithium Tantalate shows no difference in piezoelectric properties from standard wafers
  • High uniformity of Bulk Resistivity throughout the surface and depth of wafers
  • Yellow (High physical strength) material now available
 

Typical properties of Black Lithium Tantalate

Black Lithium Tantalate Standard Lithium Tantalate
 
Standard Black
Super Black
Bulk Resistivity (Ω · cm)
2.30E+11
2.10E+10
4.50E+10
Bulk Conductivity (&Omega-1; · cm-1)
4.35E-12
4.76E-11
2.22E-15
Surface Electric Potential(Note 1) /100mmφ(kV)
<0.35
<0.08
4.12
Electrical Charge neutralisation (sec)
3.5
1.5
∞ 
Optical Transmission%(Note 2)
65
<60
72
Colour
Grey
Dark Grey
Colourless

(1) Electrical charges due to temperature rising above room temperature to 95°C, at 4 inch LT wafer

(2) Transmission of 0.35mm thickness wafer (with both sides mirror polished) measured by 365nm wavelength

SAW Properties

Lithium Tantalate 42° Y-cut
 
Black
Standard
Curie temperature Tc (°C)
602.5±2
602.5±2
SAW velocity
Unchanged
4022 (note 3)
Coupling coefficient k2
Unchanged
7.6

(3) Surface skimming bulk wave

Comparisons for Lithium Tantalate Material

Comparison of electrical potential between black lithium tantalate and standard lithium tantalate when placed on a hotplate at 95°C  
Black Lithium Tantalate - Endurance Test against High Temperature  
Black Lithium Tantalate - Optical Transmission Spectra  

Specification of Bulk Resistivity

Standard Black Super Black
Bulk Resistivity (Ω · cm) 0.9E+11 ˜ 9.0E+11 1.0E+10 ˜ 9.0E+10
Bulk Conductivity (Ω · cm-1) 1.1E-11 ˜ 1.11E-12  1.0E-10 ˜ 1.11E-11 

Typical Specifications

Orientation Diameter Thickness Surface Finish
 
(+) plane
(-) plane
36 ° Y-cut 

76.2(mm)

100.0(mm)

0.25(mm)

0.35(mm)

0.50(mm)

Mirror Polished

GC#1000

GC#1200

GC#2500

39 ° Y-cut
42 ° Y-cut 
46 ° Y-cut 
48 ° Y-cut 
X-cut 

In addition to the above, we can apply our de-oxidation treatment to Lithium Tantalate wafers of any specification.