Key Applications and Strategic Value of Precious Metals in the Semiconductor Industry Chain

Keywords: Precious Metals; Semiconductor; Electronics Industry; Gold; Platinum Group Metals; Industry Chain

Introduction

Precious metals, words that have been closely linked to wealth, power, and aesthetics since ancient times, have gained new vitality in modern industrial civilization. Gold, silver, platinum group metals (platinum, palladium, rhodium, iridium, ruthenium, osmium) are indispensable strategic materials in high-end manufacturing due to their excellent physical and chemical properties—outstanding conductivity, high chemical inertness, remarkable ductility, and unique catalytic activity. Particularly in the semiconductor industry, the core driver of today’s digital wave, precious metals play an irreplaceable key role. From smartphone processors to artificial intelligence chips, from 5G communication base stations to power devices for new energy vehicles, precious metals support the trillion-dollar electronic information industry with extremely small amounts. This article aims to systematically review the application scenarios, demand logic, and strategic significance of precious metals in the semiconductor industry chain, revealing how these seemingly ancient metals have become the most solid cornerstone of modern technology.

I. Overview of Precious Metals: Definition and Characteristics

Precious metals are chemically defined as transition metals, characterized by high electrode potential, strong oxidation resistance, good ductility, scarcity, and uneven distribution. According to the United Nations International Trade Centre classification, commonly used industrial precious metals mainly include:

• Gold (Au): Density 19.32 g/cm³, melting point 1064°C, resistivity 2.44×10⁻⁸ Ω·m. Due to its excellent corrosion resistance and superior electrical conductivity, it is the preferred material for electronic connectors and wire bonding.
• Silver (Ag): The highest electrical conductivity among all metals (resistivity 1.59×10⁻⁸ Ω·m), but prone to tarnishing, mainly used in pastes and coatings.
• Platinum (Pt): Resists high-temperature oxidation, high melting point (1768°C), widely used in semiconductor thin-film deposition and catalysts.
• Palladium (Pd): Similar to platinum but lighter, widely used in multilayer ceramic capacitors and packaging solders.
• Rhodium (Rh): High hardness, good reflectivity, used for special electrodes and high-temperature coatings.
• Iridium (Ir): One of the most corrosion-resistant metals, used for electrodes and contacts in extreme environments.
• Ruthenium (Ru): Used as a substitute for platinum in advanced DRAM capacitor electrodes, with excellent compatibility with high-k dielectrics.

Global precious metal reserves are highly concentrated, with South Africa, Russia, Chile, Peru, and a few other countries controlling the vast majority of platinum group metal resources, while gold reserves are scattered across South Africa, China, Australia, Russia, and others. This asymmetry in resource endowment gives the precious metal supply chain natural strategic vulnerability.

II. Core Applications of Precious Metals in Semiconductor Manufacturing

2.1 Wire Bonding and Package Interconnects

In semiconductor packaging, gold serves as the blood vessels connecting the chip pad to external leads. Gold wire bonding, with its extreme ductility (one gram of gold can be drawn into thousands of meters of fine wire), excellent fatigue resistance, and stable electrochemical characteristics, has long dominated high-end chip packaging. Although copper wire and silver wire technologies have gradually been promoted in recent years due to cost advantages, gold wire remains irreplaceable in extremely reliability-demanding applications such as automotive electronics, aerospace, and high-frequency RF chips. For example, radar chips used in autonomous driving systems operate in temperature ranges from -40°C to 175°C; only gold wire can maintain bond strength under such drastic thermal cycling.

2.2 Multilayer Ceramic Capacitor (MLCC) Electrodes

MLCCs are the most widely used passive components in modern electronic devices; a smartphone may contain thousands of MLCCs. Silver and palladium play key roles as inner electrodes in MLCCs. Silver is the mainstream choice due to its high conductivity and relatively low cost, while palladium, because of its stable compatibility with ceramic dielectrics during high-temperature co-firing (around 1300°C), is used in high-capacitance and high-reliability products. With the explosive growth of MLCC demand from electric vehicles and 5G base stations, palladium price fluctuations directly impact the cost curve of the entire capacitor industry.

2.3 Thin-Film Deposition and Electrode Preparation

In front-end semiconductor processes, precious metals are often used to form ohmic contact electrodes, Schottky diode electrodes, and electrodes for ferroelectric memory (FeRAM). For example, platinum and iridium, due to their high work function and oxidation resistance, are widely used for metal gates on high-k gate dielectrics (such as HfO₂). The Ti/Pt/Au multilayer metallization system is the most classic electrode structure for GaAs and GaN RF devices: the titanium layer provides adhesion, the platinum layer acts as a barrier preventing gold from reacting with the substrate, and the gold layer provides low-resistance conduction. Similarly, in SiC power devices, Ni/Au ohmic contacts are the mainstream technology route.

2.4 Key Materials for Advanced DRAM and Logic Chips

In DRAM memory manufacturing, capacitor electrode materials have evolved from polysilicon to Ti/Ru and then to Ir/Pt. As process dimensions shrink below 1x nm, leakage current and reliability issues of traditional electrode materials become prominent; ruthenium, with its high work function (about 4.7 eV) and good lattice matching with high-k dielectrics, becomes the preferred substitute for platinum. In logic chips, iridium-based materials are being explored for next-generation phase-change memory (PCM) and resistive memory (RRAM). Notably, although the annual global consumption of precious metals for semiconductor manufacturing accounts for a very small proportion of total mining output (about 0.1% for gold, about 5% for platinum group metals), their unit value is extremely high, and process purity requirements exceed 99.999%.

III. Precious Metal Demand Mapping in the Semiconductor Industry Chain

To deeply understand the role of precious metals in the semiconductor system, it is necessary to overview the entire industrial chain structure. The semiconductor industry chain can be divided into three major segments: design, manufacturing and packaging/testing, and supporting equipment and materials.

As clearly shown in the diagram, precious metals mainly act in manufacturing and packaging/testing segments. In the design segment (EDA tools, IP cores), precious metals have no involvement; in materials such as photoresists, electronic gases, and silicon wafers, precious metals infiltrate through coating targets, bonding wires, and solders. Specifically:

• Manufacturing segment: Platinum, ruthenium, iridium, etc., are used for thin-film deposition targets (PVD and CVD precursors) and as chromium coatings for photomasks (though not precious metal, gold often serves as barrier layer). Currently, the global target market is dominated by Japanese, American, and German companies, with gross margins for precious metal targets exceeding 50%.
• Packaging/testing segment: Gold wire, silver paste, and palladium-silver solder paste are core consumables. For example, packaging a 12-inch wafer fab with a monthly capacity of 60,000 wafers requires gold wire worth millions of dollars. Additionally, rhodium coatings used on test probe cards significantly extend probe life and reduce testing costs.

The further downstream in the industrial chain, the more concentrated the added value and importance of precious metals. Advanced system-in-package (SiP) and 3D heterogeneous integration place higher demands on the precision and reliability of precious metal interconnects, which in turn drives continuous progress in precious metal processing technologies (such as fine bonding and nano-coating).

IV. Impact of Precious Metal Price Fluctuations on Semiconductor Costs

Precious metal prices are highly volatile and have financial attributes. Taking gold as an example, during the global pandemic in 2020, gold prices once broke through $2,000 per ounce, and between 2024 and 2026, due to geopolitical factors and Fed policy, gold prices fluctuated sharply in the range of $1,800–$2,400 per ounce. For semiconductor practitioners, this volatility directly translates into cost pressure:

• Packaging costs: Gold wire cost typically accounts for 15%-25% of total packaging materials. If gold prices rise by 20%, the gross margin of chip packaging/testing may drop by 2-3 percentage points. Although leading packaging/testing vendors can smooth the impact through hedging (financial derivatives), small and medium-sized vendors face severe challenges.
• Capacitor costs: Palladium prices hit an all-time high of $3,000 per ounce in 2021, directly pushing up MLCC prices by 15%-30%. Downstream customers (such as smartphone brands) had to adjust stocking strategies or accept longer lead times.
• Target costs: Precious metal target prices are highly linked to spot metal prices, and processing loss rates are high (typically 20%-30%), further amplifying cost sensitivity.

To cope with price risks, various substitution solutions have emerged in the industry: copper wire replacing gold wire, base metal electrodes (e.g., nickel electrodes) replacing silver/palladium electrodes, and reducing coating thickness. However, these substitutions often come at the expense of some performance, and are still prohibited in special applications such as aerospace and military.

V. Conservation and Substitution Technologies: Balancing Performance and Cost

Faced with the scarcity of precious metal resources and price volatility, the semiconductor industry has invested heavily in R&D seeking technological breakthroughs. The following are the main conservation and substitution paths:

1. Copper wire bonding: Copper wire has slightly higher resistivity than gold wire (1.68 vs. 2.44×10⁻⁸ Ω·m), but costs only 1/50 to 1/80 of gold wire. However, copper is prone to oxidation and has high hardness, requiring inert gas protection and narrower bonding parameter windows. Currently, copper wire is widely used in consumer-level packaging but requires caution in high-reliability scenarios.
2. Silver wire bonding and silver paste: Silver has better conductivity than gold, but is prone to sulfidation. Adding a small amount of palladium to silver (forming silver-palladium alloy) can effectively suppress sulfidation. This method is gradually being promoted in LED packaging and power modules.
3. Coating thinning and selective plating: By optimizing the electroplating process, the gold coating thickness can be reduced from traditional 0.5μm to 0.2μm, saving 60% of gold usage. Selective plating technology (such as mask plating) deposits precious metal only on necessary areas, avoiding waste.
4. Nano-scale precious metal alloys: Develop nano-alloys of precious metals and base metals to reduce precious metal content without significantly sacrificing conductivity. For example, gold-copper alloys maintain good bonding performance while reducing gold content to 30%.

These substitution technologies are not achieved overnight; they often require lengthy reliability verification (e.g., high-temperature aging, temperature cycling, humidity testing). For automotive-grade and military-grade chips, certification cycles may take 3-5 years.

VI. Prospects and Strategic Implications

Looking ahead, the status of precious metals in the semiconductor field will show a trend of stable volume and increasing price. On one hand, advanced packaging (e.g., 2.5D/3D packaging) continues to grow demand for high-performance interconnects, so the usage of gold, palladium, etc., will not decline significantly; on the other hand, with global energy transition and EV popularization, mass production of wide-bandgap semiconductor devices such as SiC and GaN will drive demand for platinum, ruthenium, etc., in electrodes. Meanwhile, maintenance and replacement of key precious metal components (such as heaters, sensors, plasma electrodes) in semiconductor manufacturing equipment (e.g., thin-film deposition equipment) will also generate stable demand.

From a geopolitical perspective, the precious metal supply chain is highly sensitive. South Africa’s platinum group metal production is significantly affected by power shortages and political and economic turmoil, while Russia’s palladium supply faces sanction risks. Semiconductor companies are actively promoting supply chain diversification, including developing precious metal recycling technologies (recovering gold, silver, and platinum group metals from waste circuit boards and chip scraps, with recovery rates over 95%), establishing strategic reserves, and investing in alternative material R&D. As the world’s largest semiconductor consumer market and manufacturing base, China has relatively scarce precious metal resources, and needs to achieve resilient development through technology reserves and circular economy.

Conclusion

The combination of precious metals and the semiconductor industry is essentially a dynamic game between physical limits and economic trade-offs. Without the excellent performance of gold and platinum group metals, semiconductor manufacturing cannot break through reliability bottlenecks; excessive reliance on precious metals, however, would lead to cost out of control and fragile supply chains. In the future, the semiconductor industry will seek a finer balance between optimal performance and cost control, and the role of precious metals will gradually shift from protagonist to key supporting role—continuing to play a decisive role in nodes that cannot be replaced. For practitioners and investors, understanding the real value and risk paths of precious metals in the semiconductor industry chain is key to grasping the industry pulse.