19AUGUST 2023Operating with powers up to 30 kW, these supplies have been specifically designed to optimize outputs and deliver precise and repeatable sputtering of thin films by combining a patented pulsing technology with a variety of additional parameters for real-time control ­ even when plasma impedance changes abruptly. The AP waveform delivers boost voltage, reverse voltage control, and advanced pulse shaping with precise frequency control in 1 kHz increments up to 150 kHz and duty cycles down to 60 percent. Dead time delay between pulses can be configured from 0 to 1µs. The result is a system that allows manufacturers to fine-tune the process for tailored film morphologies and desired film properties. Figure 1 shows an example of the waveform at the power supply output and the resulting waveform at the plasma in a single-magnetron sputtering application. The reverse portion of the waveform maximizes control, allowing more definitive charge clearing during the reverse cycle.In Figure 2, we see how precise control of the generator's output can be used to manage the waveform at the plasma in a dual-magnetron sputtering application. In this case, the power supply is able to control power delivery to each magnetron independently for uniform target utilization. By using a patented boost circuit on the leading edge of the sputtering waveform, the supply is able to accelerate the delivery of power to the process compared to a more conventional sine wave generator.Advanced Arc ManagementThe AP family also includes a number of features to deliver advanced arc management. These include current and voltage sensing that provides the ability to sense and respond to arcs in under 1 µs and to proactively inhibit arcs ­ even at higher power levels. The addition of current sensing provides more accurate arc responses, resulting in less process interruptions due to false arcs.As Figure 3 illustrates, advanced arc handling includes a four-block progressive arc management system with the capability for full voltage reversal bringing the current to 0A in just 3 to 4µs. Because each block has its own individual, self-adjusting arc parameters that can be fixed or dynamically move with the process, responses can be tailored to a wide range of process steps and applications in real time.Process Characterization and OptimizationDriven by the need to maximize both quality and productivity, there is a growing demand for power supplies that help operators gain insight into system operation and provide the actionable intelligence needed to improve process characterization and optimization. This is leading to power supply manufacturers developing suites of hardware and software tools that, when used in conjunction with the power generators themselves, allow both real-time and historical analysis of key conditions including process steps, pulse shapes, micro- and hard-arc events, changes in arc rates and, in dual-magnetron applications, possible imbalances across sides A and B. To address these requirements, Advanced Energy developed its own data acquisition and visualization tools known as FastDAQTM and PowerInsight by Advanced EnergyTM.Eliminating the need for an oscilloscope and operating with a sample rate of up to 40 MHz, FastDAQ is a built-in oscilloscope capability that provides measurement of the critical parameters for advanced process development and system troubleshooting. Connected to a PC or a local network via an Ethernet port, FastDAQ includes a "flight recorder" for storing long-term data, viewing historical performance, reviewing events and process steps and monitoring arcs alongside visualization tools that include real-time, and historical dashboards for rapid diagnostics and data exploration. PowerInsight takes this analysis one stage further by bringing together machine learning, modern data science, and advanced analytics to enrich data and diagnostics and provide predictive and prescriptive insights that transform the information into actionable intelligence for fine tuning the process to improve yield and reduce unplanned downtime. Figure 1: Waveform control in a single-magnetron sputtering application (diagram from Ascent® AP datasheet)Figure 2: Waveform control in a dual-magnetron sputtering application (diagram from Ascent AP® datasheet)Figure 3: Four-block progressive arc management system dynamically adjusts with the processFigure 4: FastDAQ data acquisition and visualization toolAs transistor density increases and semiconductor processes scale down to deliver new architectures at ever-smaller technology nodes
< Page 9 | Page 11 >