4.1 This guide recommends the water quality required for the electronics and microelectronics industries. High-purity water is required to prevent contamination of products during manufacture, since contamination can lead to an unacceptable, low yield of electronic devices.
4.2 The range of water purity is defined in accordance with the manufacturing process. The types of ultra-pure water are defined with respect to device line width. In all cases, the water-quality recommendations apply at the point of distribution.
4.3 The limits on the impurities are related to current contamination specifications and to available analytical methods (either performed in a suitable clean laboratory or by on-line instrumentation). On-line and off-line methods are used in accordance with current industry practice. Concentration of the sample may be required to measure the impurities at the levels indicated in Table 1.
Parameter | Type E-1 | Type E-1.1 | Type E-1.2B | Type E-1.3B | Type E-2 | Type E-3 | Type E-4 |
Linewidth (microns) | 1.0–0.5 | 0.35–0.25 | 0.18–0.09 | 0.065–0.032 | 5.0–1.0 | >5.0 | — |
Resistivity, 25°C (On-line) | 18.1 | 18.2 | 18.2 | 18.2 | 16.5 | 12 | 0.5 |
TOC (μg/L) (on-line for <10 ppb) | 5 | 2 | 1 | 1 | 50 | 300 | 1000 |
On-line dissolved oxygen (μg/L) | 25 | 10 | 3 | 10 | — | — | — |
On-Line Residue after evaporation (μg/L) | 1 | 0.5 | 0.1 |
| — | — | — |
On-line particles/L (micron range) |
|
|
|
|
|
|
|
>0.05 μm |
|
|
| 500 |
|
|
|
0.05–0.1 |
| 1000 | 200 | N/A | — | — | — |
0.1–0.2 | 1000 | 350 | <100 | N/A | — | — | — |
0.2–0.5 | 500 | <100 | <10 | N/A | — | — | — |
0.5-1.0 | 200 | <50 | <5 | N/A | — | — | — |
1.0 | <100 | <20 | <1 | N/A | — | — | — |
SEM particles/L (micron range) |
|
|
|
|
|
|
|
0.1–0.2 | 1000 | 700 | <250 | N/A | — | — | — |
0.2–0.5 | 500 | 400 | <100 | N/A | 3000 | — | — |
0.5–1 | 100 | 50 | <30 | N/A | — | 10 000 | — |
10 | <50 | <30 | <10 | N/A | — | — | 100 000 |
Bacteria in CFU/Volume |
|
|
|
|
|
|
|
100 mL Sample | 5 | 3 | 1 | N/A | 10 | 50 | 100 |
1 L Sample |
|
| 10 | 1 |
|
|
|
10 L Sample |
|
|
| 1 |
|
|
|
Silica – total (μg/L) | 5 | 3 | 1 | 0.5 | 10 | 50 | 1000 |
Silica – dissolved (μg/L) | 3 | 1 | 0.5 | 0.5 | — | — | — |
Anions and Ammonium by IC (μg/L) |
|
|
|
|
|
|
|
Ammonium | 0.1 | 0.10 | 0.05 | 0.050 | — | — | — |
Bromide | 0.1 | 0.05 | 0.02 | 0.050 | — | — | — |
Chloride | 0.1 | 0.05 | 0.02 | 0.050 | 1 | 10 | 1000 |
Fluoride | 0.1 | 0.05 | 0.03 | 0.050 | — | — | — |
Nitrate | 0.1 | 0.05 | 0.02 | 0.050 | 1 | 5 | 500 |
Nitrite | 0.1 | 0.05 | 0.02 | 0.050 | — | — | — |
Phosphate | 0.1 | 0.05 | 0.02 | 0.050 | 1 | 5 | 500 |
Sulfate | 0.1 | 0.05 | 0.02 | 0.050 | 1 | 5 | 500 |
Metals by ICP/MS (μg/L) |
|
|
|
|
|
|
|
Aluminum | 0.05 | 0.02 | 0.005 | 0.001 | — | — | — |
Antimony |
|
|
| 0.001 |
|
|
|
Arsenic |
|
|
| 0.001 |
|
|
|
Barium | 0.05 | 0.02 | 0.001 | 0.001 | — | — | — |
BoronC | 0.3 | 0.1 | 0.05 | 0.050 | — | — | — |
Cadmium |
|
|
| 0.010 |
|
|
|
Calcium | 0.05 | 0.02 | 0.002 | 0.001 | — | — | — |
Chromium | 0.05 | 0.02 | 0.002 | 0.001 | — | — | — |
Copper | 0.05 | 0.02 | 0.002 | 0.001 | 1 | 2 | 500 |
Iron | 0.05 | 0.02 | 0.002 | 0.001 | — | — | — |
Lead | 0.05 | 0.02 | 0.005 | 0.001 | — | — | — |
Lithium | 0.05 | 0.02 | 0.003 | 0.001 | — | — | — |
Magnesium | 0.05 | 0.02 | 0.002 | 0.001 | — | — | — |
Manganese | 0.05 | 0.02 | 0.002 | 0.010 | — | — | — |
Nickel | 0.05 | 0.02 | 0.002 | 0.001 | 1 | 2 | 500 |
Potassium | 0.05 | 0.02 | 0.005 | 0.001 | 2 | 5 | 500 |
Sodium | 0.05 | 0.02 | 0.005 | 0.001 | 1 | 5 | 1000 |
Strontium | 0.05 | 0.02 | 0.001 |
| — | — | — |
Tin |
|
|
| 0.010 |
|
|
|
Titanium |
|
|
| 0.010 |
|
|
|
Vanadium |
|
|
| 0.010 |
|
|
|
Zinc | 0.05 | 0.02 | 0.002 | 0.001 | 1 | 5 | 500 |
Temperature Stability (K) |
|
|
| ±1 |
|
|
|
Temperature Gradient (K/10 min) |
|
|
| <0.1 |
|
|
|
Dissolved Nitrogen On-line (mg/L) |
|
|
| 8-18 |
|
|
|
Dissolved Nitrogen Stability (mg/L) |
|
|
| ±2 |
|
|
|
All values are equal to or less than with the exception of Resistivity.
1.1 This guide provides recommendations for water quality related to electronics and semiconductor-industry manufacturing. Seven classifications of water are described, including water for line widths as low as 0.032 micron. In all cases, the recommendations are for water at the point of distribution (POD).
1.2 Water is used for washing and rinsing of semiconductor components during manufacture. Water is also used for cleaning and etching operations, making steam for oxidation of silicon surfaces, preparing photomasks, and depositing luminescent materials. Other applications are in the development and fabrication of solid-state devices, thin-film devices, communication lasers, light-emitting diodes, photo-detectors, printed circuits, memory devices, vacuum-tube devices, or electrolytic devices.