Reducing Leakage Current in Advanced Semiconductor Devices

Leakage current is an increasingly visible constraint in modern semiconductor technology causing limitations for business and component performance. In advanced devices with smaller node sizes, even small unwanted currents can significantly impact power consumption, device reliability, signal integrity, and manufacturing yield.

This article explains what leakage current is, why it arises, and most crucially how surface quality and interface defect control can be leveraged to reduce leakage current in advanced semiconductor devices.

What Is Leakage Current and Why It Matters

In semiconductor devices, leakage current refers to unintended current flow when a device should ideally be non-conductive, so called off-stage. In practice, this can appear as off-state current in transistors, reverse bias leakage in diodes, or parasitic current paths that detract from intended operation. At smaller nodes, leakage current can rise to levels that meaningfully affect static power and noise margins even in digital logic, and more so in analog, memory, and sensor circuits.

Industry has been reporting from low yield due to leakage current as well as from delayed technology adaptation due to increased leakage current. These reports are emphasizing how important the leakage current management is.  The table below summaries the key business consequences.

Leakage current also correlates with reliability and heat generation: increased leakage tends to increase power dissipation and accelerate degradation mechanisms in semiconductor packages. In memory devices, sustained leakage under stress can degrade oxide layers and hasten failure mechanisms.

Business Impact from Leakage Current

It’s important to understand that reducing leakage current by 50%+ is not just a technical achievement. It delivers measurable business value as well.

For advanced semiconductor nodes, even a modest leakage reduction can improve manufacturing yield by 3–5%, translating into millions of dollars in cost savings per production run.

Lower leakage also reduces static power consumption, enabling energy-efficient designs that meet stringent market requirements for AI, automotive, and IoT applications.  

Beyond the cost, the improved reliability minimizes warranty risks and smaller leakage current in chips accelerates time-to-market, giving manufacturers a competitive edge in high-growth segments. Companies that master leakage control will lead in energy efficiency and reliability – critical differentiators in next-gen semiconductor markets.

In short, mastering leakage control is a direct lever for profitability, sustainability, and market leadership.

Root Causes: Atomic-Level Defects and Interface Trap States

A central insight in leakage current physics is that unwanted currents often arise from localized defect states within or adjacent to critical interfaces within a semiconductor device. These defect states can exist in dielectric materials, at interfaces between silicon and oxides, or around contamination sites left from imperfect processing.

Atomic-level defects and contaminants create mid-gap trap states at surfaces and interfaces, interfering with charge transport and increasing leakage currents and power consumption.

More specifically:

• Defect states near the semiconductor/insulator interface act as stepping stones that enable carriers to traverse what should be an insulating barrier.
• These trap states increase leakage conduction paths and reduce effective isolation.
• Variability in defect densities contributes to variability in device leakage and reliability performance.

External first-principles studies corroborate this mechanism: theoretical work on the Si/SiO₂ interface shows that even a small number of dangling bonds and interface defects can increase leakage current by hundreds of times  compared to defect-free interfaces.

How Interface Defect Density Drives Leakage

In advanced devices, e.g. GAA, CMOS, memory, and sensor, leakage mechanisms include subthreshold leakage, gate-oxide tunnelling, trap-assisted tunnelling, and stress-induced leakage due to charge trapping at defect sites. Defects can also introduce variability and noise, further impacting performance in sensitive analog or RF circuits.

Interface defect density (often termed Dit) is a key driver of device leakage. High Dit increases trap-assisted conduction pathways and undermines threshold stability and isolation. 

Strategies for Reducing Leakage Current

To effectively reduce leakage current in advanced devices, it is necessary to address both device physics and material/process quality factors that contribute to leakage.

1. Minimize Interface Defects Through Advanced Surface Preparation

Improving surface quality at the atomic level reduces the density of defects that give rise to trap-assisted leakage. SisuSemi’s research and solution approach leverage atomic-level surface cleaning techniques that have demonstrated measurable improvements in electrical performance, including reduced leakage current and lower defect density in advanced nodes. 

Improving surface cleaning can be complementary to process steps such as atomic layer deposition (ALD) of gate dielectrics and controlled oxidation to form high-quality crystalline or near-crystalline interface layers, which have lower trap densities than poorly ordered oxides. 

2. Passivation of Trap States

Passivation techniques, including hydrogen termination and controlled pre-oxide treatments, can neutralize active trap sites at the silicon/dielectric interface, reducing their ability to support leakage pathways. Studies on silicon oxide passivation show that such treatments can significantly lower interface defect densities and concomitantly reduce leakage current in photodiodes and similar structures. 

3. Controlled Process Integration

Integrating cleaning, passivation, and interface formation steps in a controlled environment – such as ultra-high vacuum or tightly regulated oxidation sequences – can maximize the quality of critical interfaces and prevent recontamination that would otherwise increase leakage. SisuSemi’s advanced surface treatment technology has been successfully applied to MOS capacitors, photodetectors, and p-n diodes, yielding leakage current reductions between roughly 50% and 75% in these components.

Measurable Impact: Case Study Results

Leakage current is not fixed by material and chip design – it’s also driven by the interface quality and atomic level cleanliness. Our Case Studies shows how leakage current can be reduced with commercial components:

• MOS capacitors treated with advanced interface preparation exhibited 67% lower leakage current and a 42% reduction in interface defect density. 
• Photodetectors saw ~50% leakage reduction, improving detection sensitivity and noise performance. 
• p–n diodes experienced up to a 75% decrease in leakage, enhancing stability in extreme environments. 
• Radiation Detector Sensors experienced up to 80% reduction in leakage and up-to 75% variation reduction, leading to lower calibration cost and more stable product performance.

These improvements not only reduce static power and error rates but also improve manufacturing yield and reliability, enabling devices to meet stricter performance and quality requirements.

Conclusion: Leakage Reduction Begins at the Interface

Reducing leakage current in advanced semiconductor devices is not solely a matter of circuit optimization; it is fundamentally tied to material quality at the atomic scale. Defects and contaminants at critical interfaces create trap states that enable unintended current paths and increase power consumption. Through improved surface preparation, defect passivation, and tightly controlled process integration, manufacturers can substantially reduce leakage paths, improve energy efficiency, and enhance device performance.

As device geometries continue to shrink and performance demands increase, mastering leakage current reduction through interface control will be essential to sustaining innovation and competitiveness in semiconductor technology. SisuSemi offers one solution to enable the cleanest interfaces that leads to smallest leakage currents. Reach out to learn more.