Wafer cleaning&chip manufacturing

I. User Pain Points

Semiconductor companies (wafer manufacturing, chip packaging, integrated circuits) face three core challenges in ultrapure water preparation, wafer cleaning wastewater treatment, and specialty gas purification: particulate matter/organic matter contamination, heavy metal residues, and excessive trace impurities in specialty gases. These challenges directly threaten chip yield, equipment lifespan, and product reliability.

Particulate matter/organic matter contamination leads to a sharp drop in chip yield.

Wafer cleaning uses ultrapure water (resistivity ≥18.2MΩ・cm). Suspended particulate matter (≥0.1μm, 1-100 particles/mL) and total organic carbon (1-10μg/L) exceed standards. Traditional "RO+EDI" methods can only remove 60% of the total organic carbon, leading to wafer surface defects (such as particle residues and oxide layer breakdown). Chip yield plummeted from 95% to 80%. A 12-inch wafer fab of Shanxi Xinhua Shengtan's partner suffered a 28nm process line chip yield drop to 82% due to excessive total organic carbon (8μg/L), resulting in a single batch loss of over $2 million.

Heavy metal residues cause device reliability failures.

Cleaning wastewater contains copper, nickel, and iron. Traditional ion exchange resins remove less than 50% of the copper, exceeding the emission concentration requirements of the international semiconductor technology roadmap. A chip packaging plant, a client of Shanxi Xinhua Shengtan, experienced solder joint corrosion failure due to copper residue (1.5 μg/L), resulting in customer returns and losses exceeding $1.5 million.

Excessive trace impurities in specialty gases lead to process control failures.

Chip manufacturing uses high-purity silane and ammonia, which contain excessive trace amounts of oxygen and moisture. Traditional molecular sieve adsorption can only remove 70% of oxygen and water, leading to uneven thickness of chemical vapor deposition films. An integrated circuit plant, a client of Shanxi Xinhua Shengtan, experienced gate oxide layer defects due to excessive oxygen in silane (5 ppb), resulting in the scrapping of an entire batch of wafers and losses exceeding $3 million.

II. Application Objectives

Semiconductor companies adopt activated carbon for four core purposes, focusing on "deep purification of ultrapure water, extreme removal of heavy metals, control of trace impurities in special gases, and assurance of chip yield": Deep purification of ultrapure water to ensure chip yield: Mesoporous activated carbon (55% 2-50nm, specific surface area 1800-2500m²/g) adsorbs total organic carbon and particulate matter, with an adsorption capacity of 200-300mg/g. Surface modification enhances the adsorption of polar organic matter, resulting in effluent water with total organic carbon <1μg/L and particulate matter (≥0.1μm) <1 particle/mL. After using this method, a 12-inch wafer fab of Shanxi Xinhua Shengtan's partner saw its 28nm chip yield increase from 82% to 94.5%.

Heavy metal removal at its maximum extent ensures device reliability.

Modified activated carbon is used to adsorb copper, nickel, and iron, with adsorption capacities reaching 150-250 mg/g (copper) and 100-200 mg/g (nickel). Stable sulfides are formed through complexation precipitation, resulting in emission concentrations of copper <0.05 μg/L and nickel <0.02 μg/L. After use by a chip packaging plant, a client of Shanxi Xinhua Shengtan, solder joint corrosion failure was reduced to zero.

Specialty gas trace impurity control prevents process runaway.

Hydrophobic hydroporous activated carbon is used to adsorb oxygen and moisture, with adsorption capacities reaching 50-100 mg/g (oxygen) and 100-200 mg/g (water). Specialty gas purity is improved to <0.5 ppb oxygen and <0.5 ppb water in silane. After use by an integrated circuit plant, a client of Shanxi Xinhua Shengtan, film thickness uniformity (±3%) met standards, and no wafer scrap was achieved.

Strict Compliance, Meeting Global Semiconductor Standards

Meets global semiconductor industry standards:

• Total organic carbon in ultrapure water ≤ 1 μg/L, particulate matter (≥0.1 μm) ≤ 1 particle/mL;
• Heavy metals (copper, nickel, iron) ≤ 0.1 μg/L;
• Oxygen and water in high-purity gases ≤ 1 ppb.

III. Application Significance

The application of activated carbon in semiconductor companies is a core support for companies' "chip yield baseline + device reliability + process stability":

Chip yield baseline: 25% of global wafer fabs suffer yield losses due to water quality issues. Activated carbon is one of the few technologies that can simultaneously and deeply remove total organic carbon and particulate matter at a controllable cost, directly avoiding large batch losses.

Device reliability assurance: Heavy metal residual concentration is reduced from micrograms to nanograms, solder joint corrosion failure is eliminated, and customer return losses are significantly reduced.

Process stability control: Trace impurities in specialty gases are reduced from ppb levels to sub-ppb levels, improving the stability of chemical vapor deposition processes and significantly reducing wafer scrap rates. IV. Application History The application of activated carbon in semiconductor companies has deepened with the advancement of "process node miniaturization + upgraded purity requirements":

1990s: Initial Stage
Intel was the first to use granular activated carbon to treat the total organic carbon (TOC) in ultrapure water (10 μg/L), reducing it to 5 μg/L through adsorption and regeneration. This marked the world's first attempt to apply activated carbon to semiconductor ultrapure water treatment.

2010s: Promotion Stage
Relevant water quality standards were released, requiring TOC ≤ 1 μg/L, promoting the widespread adoption of mesoporous activated carbon. In 2015, Intel reduced the TOC in its 28nm production line's ultrapure water from 8 μg/L to 0.8 μg/L, becoming the first wafer fab in China to obtain the corresponding certification.

V. Mechanism of Action

Activated carbon addresses the semiconductor industry's problems of "total organic carbon/particulate matter contamination, heavy metal residue, and special gas impurities" through a triple action: mesoporous purification of ultrapure water, modified heavy metal removal, and hydrophobic purification of special gases.
Mesoporous Purification of Ultrapure Water: The pore structure and surface modification work synergistically. The mesopores preferentially adsorb small-molecule organic matter and intercept particulate matter through size exclusion effects. Surface modification enhances the adsorption of polar organic matter through hydrogen bonding. The total organic carbon adsorption capacity is 200-300 mg/g, with a removal rate >99%.
Modified Heavy Metal Removal: Thiourea, through complexation precipitation, combines with copper, nickel, and iron via complexation reactions to form sulfide precipitates. This results in high adsorption capacity and emission concentrations far exceeding standard limits.
Hydrophobic Purification of Special Gases: The hydrophobic and adsorption synergistically work. The hydrophobic mesopores repel polar water molecules while adsorbing nonpolar oxygen molecules through van der Waals forces. The adsorption capacity is stable, reducing oxygen and water content in special gases to sub-ppb levels.
Hydrophobic Purification of Special Gases: VI. Application Methods Semiconductor companies employ a combined process of "ultrapure water deep purification + heavy metal extreme removal + special gas trace impurity control," covering all scenarios from wafer cleaning and chip packaging to integrated circuit manufacturing:

1. Ultrapure Water Deep Purification: Mesoporous Granular Activated Carbon Refining Process
Applicable Scenario: Ultrapure water from wafer cleaning, requiring total organic carbon ≤1μg/L. Process Steps: Mesoporous Granular Activated Carbon Preparation: Coconut shell granular activated carbon is activated with potassium hydroxide, washed with water, and dried to achieve the specified pore size distribution, specific surface area, and functional group loading. Refining Treatment: Reverse osmosis + electro-desalination effluent enters the mesoporous granular activated carbon refining tower, controlling the flow rate to ensure total organic carbon <0.8μg/L and particulate matter (≥0.1μm) <0.5 particles/mL in the effluent.

2. Heavy Metal Extreme Removal: Modified Granular Activated Carbon Terminal Polishing Process
Applicable Scenario: Wafer cleaning wastewater, requiring copper ≤0.1μg/L. Process Steps: 1. Modified Granular Activated Carbon Preparation: Coal-based granular activated carbon is impregnated with thiourea solution and dried to achieve the specified loading. Terminal Polishing: Wastewater enters the modified granular activated carbon polishing column, with flow rate controlled; effluent copper < 0.04 μg/L, nickel < 0.015 μg/L.

3. Special Gas Trace Impurity Control: Hydrophobic Hydroporous Granular Activated Carbon Purifier Process
Applicable Scenarios: High-purity silanes, ammonia, oxygen required, water ≤ 1 ppb. Process Steps: Hydrophobic Hydroporous Granular Activated Carbon Preparation: Coconut shell carbon is activated and hydrophobically modified with a silane coupling agent to achieve the specified pore size, specific surface area, and hydrophobic angle. Gas Purification: Special gas enters the hydrophobic hydroporous granular activated carbon purifier, with flow rate controlled; silane oxygen < 0.4 ppb, water < 0.3 ppb.

VII. Application Processes

Taking a 12-inch wafer fab (28nm process line) of a client of Shanxi Xinhua Shengtan as an example:
Ultrapure Water Deep Purification: Optimized mesoporous granular activated carbon was used in a purification tower with a loading of 5.5 tons. The ultrapure water flow rate was 100 m³/h, resulting in effluent with total organic carbon of 0.75 μg/L and particulate matter (≥0.1 μm) of 0.4 particles/mL, meeting industry standards.

Heavy Metal Limit Removal: A modified granular activated carbon polishing column treated cleaning wastewater at a flow rate of 20 m³/h, producing effluent with copper of 0.038 μg/L and nickel of 0.012 μg/L, meeting international semiconductor technology roadmap requirements.

Specialty Gas Trace Impurity Control: A hydrophobic mesoporous granular activated carbon purifier treated high-purity silane at a flow rate of 50 L/min, resulting in oxygen of 0.35 ppb and water of 0.28 ppb, meeting industry high-purity gas standards.

Specialty Gas Trace Impurity Control: Performance Verification

• Chip Yield: 28nm line yield increased from 82% to 94.5%, avoiding a loss of $2 million per batch;
• Device Reliability: Copper 0.038μg/L, solder joint corrosion failure reduced to zero;
• Process Stability: Oxygen in silane 0.35ppb, thin film thickness uniformity ±2.8%, wafer scrap rate reduced from 5% to 0.1%.

VIII. Application Results

After the upgrade of a 12-inch wafer fab, core indicators were significantly improved (based on actual operating data from a Shanxi Xinhua Shengtan partner customer):

Indicators	Before renovation	After renovation	Increase/Decrease:	Compliance Status
Total Organic Carbon in Ultrapure Water (μg/L)	8	0.75	Decrease by 90.6%	Compliance
Copper in Cleaning Wastewater (μg/L)	5	0.038	Decrease by 99.2%	Compliance
Oxygen in High-Purity Silane (ppb)	5	0.35	Decrease by 93%	Compliance
Chip Yield (%)	82	94.5	Increase by 15.2%	—
Annual Wafer Scrap Loss (USD Ten Thousand)	300	6	Decrease by 98%	—

IX. Core Advantages

Customized solutions for semiconductor companies possess four irreplaceable advantages:

• Highly Targeted Products, Matching Semiconductor Scenarios: We have developed dedicated mesoporous granular activated carbon, modified granular activated carbon, and hydrophobic hydroporous granular activated carbon, specifically for water purification, heavy metal removal, and specialty gas purification, addressing industry pain points directly.
• Dual Improvement in Chip Yield and Reliability: Ultrapure water with total organic carbon <1μg/L significantly improves chip yield; heavy metal residue <0.05μg/L eliminates solder joint corrosion failure, drastically reducing customer return losses.
• Compliant and Reliable, Fully Certified: Our products have passed multiple authoritative semiconductor industry certifications, fully meet global semiconductor standards, and can pass supplier audits by leading companies.

X. Cost Analysis

Cost Comparison:

Taking a wafer fab with a monthly production capacity of 30,000 12-inch wafers (28nm process) as an example, here is a cost comparison between activated carbon technology and traditional technology:

Project	Activated carbon combined process	Traditional crafts
Initial Investment (USD Ten Thousand)	150-200	100-150
Annual Operating Costs (USD Ten Thousand)	100	230
Annual Yield Loss (USD Ten Thousand)	6	300
Annual Customer Return Loss (USD Ten Thousand)	0	150
Net Lifetime Income (USD Ten Thousand/Year)	-100	-680

 XI. Why Choose Us?

Activated carbon excels in deep purification of ultrapure water and control of trace impurities in specialty gases, earning consistent customer recognition.

Technical Strength: We develop specialized activated carbon products tailored to the needs of the semiconductor industry, precisely addressing pain points in traditional processes such as excessive total organic carbon, heavy metal residues, and specialty gas impurities.

Global Service: With production bases in Shanxi, Ningxia, and Fujian (annual capacity of 45,000 tons), we support customized production and localized delivery. We provide overseas customers with full-process technical and certification services, responding to requests within 72 hours.