晶圆湿法清洗的速率检测器

In semiconductor substrate (wafer) cleaning, wet  cleaning is essential. Wet cleaning may include both chemi  cal and mechanical means for wet etching thin film layers and/or removing particles on a wafer Surface. In the current  State of art, one means of wet cleaning includes the use of  an acoustic energy cleaning device. An acoustic energy cleaning device utilizes a proceSS wherein a wafer is placed in a liquid bath and high frequency irradiation, or cavitation,  is applied to the liquid in the bath. At the same time,  chemicals in the liquid provide a Surface etching to layers on  the wafer. The Surface etching and cavitation together pro  vide mechanical and chemical actions that clean the wafer Surface.

The batch process, however, suffers from various  problems. For example, the batch process is timely. The  various Steps of etching the wafer, removing the wafer from  the liquid bath, measuring the wafer, and repeating the etch  take valuable time. The batch proceSS is clumsy and ineffi  cient. The wafer has to be moved around leading to potential risks of damaging delicate portions of the wafer. The batch  proceSS is imprecise. The timing of each cleaning etch can  only be estimated and cleaning etch results can only be  verified by removing the wafer from the bath to make  measurementS.

Described herein is a rate monitor for wet wafer  cleaning. In the following description numerous specific  details are set forth. One of ordinary skill in the art, however, will appreciate that these specific details are not necessary to  practice embodiments of the invention. While certain exem  plary embodiments of the invention are described and shown  in the accompanying drawings, it is to be understood that  Such embodiments are merely illustrative and not restrictive  of the current invention, and that this invention is not  restricted to the Specific constructions and arrangements  shown and described since modifications may occur to those  ordinarily skilled in the art.

FIG. 1 illustrates a wet cleaning system according  to one embodiment of the invention. Referring to FIG. 1, the  wet cleaning System includes a Single-wafer cleaning device  102 and a rate monitor 104 connected to the single-wafer cleaning device 102. The single-wafer cleaning device 102  is to provide a wet cleaning etch, and other cleaning pro  cesses, to a wafer. The term "wafer', as defined herein, may  encompass Semiconducting materials, non-conducting mate  rials, or combinations of Semiconducting and non-conduct  ing materials. The wafer includes a Substrate comprising any  one of various Substrate materials known in the art, Such as  monocrystalline Silicon. The wafer may also include Struc  tures and devices that have one or more insulative, Semi  insulative, conductive, or Semiconductive layerS and mate  rials. According to one embodiment of the invention, the  Single-wafer cleaning device 102 is a Single-wafer cleaning  device as described in further detail in conjunction with  FIGS. 3, 4, and 5A-5F below.

Fig3

Described herein is a rate monitor for wet wafer  cleaning. In the following description numerous specific  details are set forth. One of ordinary skill in the art, however, will appreciate that these specific details are not necessary to  practice embodiments of the invention. While certain exem  plary embodiments of the invention are described and shown  in the accompanying drawings, it is to be understood that  Such embodiments are merely illustrative and not restrictive  of the current invention, and that this invention is not  restricted to the Specific constructions and arrangements  shown and described since modifications may occur to those  ordinarily skilled in the art..