Methods and systems for rapid thermal processing

Abstract

Methods for rapid thermal processing of semiconductor substrates are provided. An exemplary method comprises directing radiant heat energy emitted from a heat source toward a backside surface of the semiconductor substrate. Systems for rapid thermal processing also are provided. The effect of the invention is that the heat energy emitted from the heat source is lead to the back of the semiconductor substrate, and the front of the semiconductor is not radiated by the heat energy, so patterns of the front of the semiconductor substrate do not influence evenness of heat flowing, alternatively, a pyrometer is arranged on the front of the semiconductor substrate because the heat source is not set in the front of the semiconductor substrate, by this the real temperature of the front of the semiconductor substrate is exactly measured, and radiation heat energy emitted from the individually heating lamp tube of the heat source is real-time controlled.

Description

technical field [0001] The present invention relates to semiconductor manufacturing process, and in particular to rapid thermal processing (rapid thermal processing), in particular to a method and system for rapid thermal processing of semiconductor substrates. Background technique [0002] Rapid high temperature processing has been widely used in different steps of semiconductor manufacturing process. For example, rapid high temperature processing can be used to deposit different films on semiconductor wafers. Rapid high temperature processing can also be used to implant semiconductor The ions or dopants in the wafer are annealed. Since the operating temperature of the rapid high temperature processing can be rapidly increased or decreased, the required process time is very short and the processing efficiency is also high. [0003] In many rapid high-temperature processing applications, it is often necessary to inject a gas of a specific composition at a specific pressure i...

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Problems solved by technology

[0005] When the wafer is subjected to rapid high-temperature processing, it is very important to uniformly heat the entire surface of the wafer. The uneven temperature distribution on the surface of the wafer will cause dislocation and distortion of the wafer. However, in the traditional In rapid high temperature processing, it is often difficult to achieve a uniform temperature distribution on the wafer surface, such as figure 1 As shown, it is difficult to adjust the relative position of individual heating units and the wafer, so that the heat energy received by each point on the wafer surface is exactly the same, therefore, a temperature gradient from the edge to the center of the wafer is formed, especially, the wafer Round edges often receive the least amount of thermal energy, as in Figure 2A As shown in Figure 2B, for the peak heating temperature of 1075°C, during the heating cycle, the temperature T1-T3 of the inner ring range is significantly higher than that of the outer ring, and the temperature distribution difference between the inner and outer rings reaches 12°C. In addition, the rapid high temperature Processes are usually operated for short periods of time, for example, about 2-15 minutes. The wafer is rapidly heated to a very high temperature and cooled down rapidly. Subtle differences in thermal energy at different points on the wafer surface can cause significant Therefore, the thermal stress at different points on the wafer surface will change, causing deformation of the wafer. In rapid thermal chemical vapor deposition (RTCVD), the deposition of different points on the wafer surface The rate will change due to temperature inhomogeneity, thus resulting in inhomogeneity in the thickness of the deposited film

[0006] In addition, many people are working on the real-time control of the radiant heat energy of individual lamp tubes to achieve uniform distribution of heat energy. In one way, an optical pyrometer (optical pyrometer) monitors the backside of the wafer with a wavelength of 2-3 microns. The temperature at different points on the surface, the monitored temperature parameters are processed by a processor (such as a computer) to generate a new set of parameters, and the energy of individual heating units is adjusted according to the new parameters to compensate for the temperature at different points on the wafer surface However, in order to achieve a uniform temperature distribution in this way, very accurate temperature measurements need to be taken by the optical pyrometer, and in practice, the temperature measurement by the optical pyrometer is often due to Distortion and errors are caused by the interference of different factors, including the reflection coefficient of the wafer, the radiation amount of the heating lamp, the radiation heat energy passed near the wafer, the heat radiation reflected by the reaction chamber wall and the chemical reaction of the deposition step generated heat

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