Heat treatment technology to meet the challenges of new processes and new materials

The heat treatment process is facing challenges from high-k and other materials, ultra-shallow bonding, strained silicon, SOI, and continuous scaling to produce more efficient and more complex devices. Although we try to avoid using new materials in technological development, when the existing process is about to reach its physical limit, we have to re-evaluate the choice of using some new materials.
Now, the semiconductor industry is at a new turning point: the distribution profile of doped impurities is approaching the nanometer level, and its distribution will seriously affect device performance. This requires us to control the impurity diffusion and activation degree to an unprecedented level, including requirements such as increasing the activation degree and reducing the thermal budget.

“The gate stack structure, substrate material and bonding formation method will all have new changes.” Applied Materials vice president and general manager of the front product department Randhir Thakur said, “New materials, new processes, new product development or New structure. If the process integration of strained silicon, improved source and SiON can continue to drive an annual performance growth rate of 17%, we will delay the demand for high-k materials. In fact, time is the key factor. Chip manufacturers have no time. To study these new materials and new functions, and introduce them into the semiconductor process, through the learning curve for proper integration, and then produce new chips, and finally put them on the market.”

With the continuous improvement of process characteristics and speed requirements, the introduction of complex microstructures and the use of special new materials, heat treatment technology is facing a series of challenges. Some of them can be temporarily delayed by continuing to tap their potential. However, the current state of the art that is constantly approaching physical limits requires us to make difficult choices among new materials. (Source: Applied Materials) Jeff Hebb, manager of RTP process technology at Axcelis Technology, believes that RTP has two important development trends. “The first is the formation of metal silicide. When we develop from 130nm to 90nm and 65nm, the metal silicide will change from cobalt silicide to nickel silicide. Almost everyone thinks that the 65nm process must use metallic nickel, and some even think that the late 90nm process era Some high-performance devices will use it.”

Paul Timans, Technical Director of Mattson Technology’s RTP Products Division, expects that the scope of RTP applications will be further expanded as the thermal budget is reduced. He said: “Since we have entered the nano world, more precise control of the impurity diffusion in the device structure will be necessary, because slight changes in the impurity profile will affect the device performance. Another very important application of RTP The field is to reduce the parasitic resistance and parasitic capacitance to a minimum through the annealing process and the optimization of the thermal activation process of doping impurities in new materials (including strained silicon and SOI).”