The most common and most likely answer to this crossword clue is the 6 letter word SILANE
S
I
L
A
N
E
Buddy explains!
The straight part
We know that "Precursor for semiconductors" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case precursor for semiconductors = silane.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does SILANE mean?
SILANE noun- Any of a group of silicon hydrides that are analogous to alkanes (the paraffin hydrocarbons); especially the parent compound SiH4
- Monosilane (SiHâ‚„)
- Any organic derivative of monosilane