20411
A 5 - 10 nm roughness correlation length is typical in metal - assisted chemical etching and resonantly scatters dominant phonons in silicon , leading to the observed ~ T ( 1 . 6 - 2 . 4 ) behavior .
 Chemical: silicon
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: silicon