Name: Suzhou cycas Microelectronics Co., Ltd.
Address: 1st floor,B06 building,No.2,Fuxing Road,Zhangjiagang Economic Development Zone,Jiangsu Province 215600PRC
隨著主流半導體工藝技術由0.18 μm 逐漸轉移到0.13 μm工藝，以及Z新的90 nm 工藝成功研發及投入使用。半導體器件的特征尺寸進一步減小，柵氧層的厚度越來越薄。90 nm工藝中，柵氧層的厚度僅為1.2 nm。如果等離子體刻蝕工藝控製不好， 則非常容易出現柵氧層的損傷；同時， 所使用的晶片尺寸增至300mm， 暴露在等離子體轟擊下的被刻蝕麵積不斷縮小，所檢測到的終點信號的強度下降，信號的信噪比降低。所有這些因素都對終點檢測技術本身及其測量結果的可靠性提出了更加嚴格的要求。在0.18 μm工藝時，使用單一的OES檢測手段就可滿足工藝需求;進入0.13 μm 工藝後，就必須結合使用OES 及IEP 兩種檢測手段。由於IEP技術可以在刻蝕終點到達之前進行預報，因而被稱為預報式終點檢測技術。 
High density plasma etcher is a key step in the manufacturing process of VLSI. Many end-point detection technologies have been developed, and the end-point detection equipment is designed to realize the real-time monitoring of the etching process. Optical emission
Optical emission spectrometry (OES) is the most widely used end-point detection method. The principle is to detect the end-point by detecting the change of the light intensity of the wavelength emitted by a reactive chemical group or volatile group in the plasma. When the atom or molecule in the plasma is excited to the excited state by the electron and returns to another energy state, it is accompanied by the light emitted by this process.
The change of light intensity can be observed from the observation hole on the side wall of the reaction chamber. The wavelength of the light wave excited by different atoms or molecules is different. The change of the light intensity reflects the change of the concentration of atoms or molecules in the plasma. There are two possible trends of the detected wavelength: one is that the light intensity of the reactant increases at the end of etching; the other is that the light intensity decreases.
Laser interference end-point method (IEP) uses a laser source to detect the thickness change of transparent film. When the thickness change stops, it means that the etching end-point is reached. The principle is that when the laser is perpendicular to the film surface, the reflected light in front of the transparent film interferes with the light reflected by the underlying material after penetrating the film.
With the transition of the mainstream semiconductor technology from 0.18 μ m to 0.13 μ m, the latest 90 nm technology has been successfully developed and put into use. The characteristic dimensions of semiconductor devices are further reduced, and the thickness of gate oxide layer is becoming thinner. In the 90 nm process, the thickness of the gate oxide layer is only 1.2 nm. If the plasma etching process is not well controlled, it is very easy to damage the gate oxide layer; at the same time, the chip size used is increased to 300 mm, the etched area exposed to the plasma bombardment is continuously reduced, the intensity of the detected end-point signal is reduced, and the signal-to-noise ratio of the signal is reduced. All of these factors put forward more strict requirements for the end-point detection technology itself and the reliability of the measurement results. In the 0.18 μ m process, the use of a single oes detection method can meet the needs of the process; in the 0.13 μ m process, the use of oes and IEP must be combined. As IEP technology can predict the etching end-point before it arrives, it is called predictive end-point detection technology.