US 12,265,327 B2
Semiconductor manufacturing apparatus and method thereof
Ching-Hai Yang, Taipei (TW); and Yao-Hwan Kao, Hsinchu County (TW)
Assigned to TAIWAN SEMICONDUCTOR MANUFACTURING CO., LTD., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Co., Ltd., Hsin-Chu (TW)
Filed on Jul. 16, 2019, as Appl. No. 16/513,119.
Claims priority of provisional application 62/711,880, filed on Jul. 30, 2018.
Prior Publication US 2020/0033723 A1, Jan. 30, 2020
Int. Cl. G03F 7/00 (2006.01); G03F 7/16 (2006.01); H01L 21/66 (2006.01); H01L 21/67 (2006.01)
CPC G03F 7/0035 (2013.01) [G03F 7/70475 (2013.01); G03F 7/70608 (2013.01); H01L 21/67253 (2013.01); H01L 22/10 (2013.01); G03F 7/162 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method, comprising:
providing a plurality of monitor wafers;
coating the plurality of monitor wafers with a plurality of coating layers of different thicknesses, respectively, wherein the plurality of coating layers are formed of a first coating material;
illuminating each of the plurality of coating layers with a first visible light to obtain a first plurality of light intensities reflected from the plurality of coating layers, respectively;
illuminating each of the plurality of coating layers with a second visible light to obtain a second plurality of light intensities reflected from the plurality of coating layers, respectively, the second visible light being different from the first visible light;
generating, based on the first plurality of light intensities and the plurality of coating layers of different thicknesses, a first polynomial function associated with the first coating material and the first visible light;
generating, based on the second plurality of light intensities and the plurality of coating layers of different thicknesses, a second polynomial function associated with the first coating material and the second visible light;
in response to a coefficient of determination of the first polynomial function being greater than a coefficient of determination of the second polynomial function, recording the first visible light and the first polynomial function as being usable for detecting a thickness of a material layer formed of the first coating material for actual semiconductor fabrication process;
creating a database comprising at least a first entry and a second entry, wherein the first entry records the first coating material, the first visible light in association with the first coating material, and the first polynomial function associated with both the first coating material and the first visible light, wherein the second entry records a second coating material, the second visible light in association with the second coating material, and a third polynomial function associated with both the second coating material and the second visible light, wherein the second coating material is different from the first coating material, and the first polynomial function is different from the third polynomial function;
after creating the database, forming a material layer over a substrate with a coating material selected from one of the first and second coating materials;
in response to the first coating material being selected to form the material layer, retrieving the first entry and selecting the first visible light for detecting a thickness of the material layer;
illuminating at least one region of the material layer with a light comprising the first visible light;
recording a strength of the first visible light reflected from the at least one region; and
determining a thickness of the material layer in the at least one region by computing the first polynomial function, the first polynomial function having a single variable, wherein the single variable is the strength of the first visible light.