Test structure and test method

A test method, comprising:

• providing a test structure, wherein the test structure comprises:
• a first interdigital structure, comprising a first conductive comb tooth portion and a second conductive comb tooth portion, wherein comb tooth ends of the second conductive comb tooth portion are inserted into the first conductive comb tooth portion, the comb tooth ends of the second conductive comb tooth portion and comb tooth ends of the first conductive comb tooth portion are arranged alternately in sequence and spaced apart, and there is a first distance between the comb tooth end of the second conductive comb tooth portion and the comb tooth end of the first conductive comb tooth portion;
• and
• a second interdigital structure, comprising a third conductive comb tooth portion and a fourth conductive comb tooth portion, wherein comb tooth ends of the fourth conductive comb tooth portion are inserted into the third conductive comb tooth portion, the comb tooth ends of the fourth conductive comb tooth portion and comb tooth ends of the third conductive comb tooth portion are arranged alternately in sequence and spaced apart, and there is a second distance between the comb tooth end of the fourth conductive comb tooth portion and the comb tooth end of the third conductive comb tooth portion, the second distance being not equal to the first distance;
• and wherein the first conductive comb tooth portion is electrically connected to the third conductive comb tooth portion, and the second conductive comb tooth portion is electrically connected to the fourth conductive comb tooth portion;
• applying a first voltage and a second voltage to two opposite ends of the test structure respectively, to measure a current flowing through the test structure, where there is a voltage difference between the first voltage and the second voltage;
• and
• determining a position of a short circuit occurred in the test structure based on the measured current and the voltage difference between the first voltage and the second voltage.