However, I have a sneaking feeling that some lesser known contemporary of his may have got there before him. Beethoven's contribution is perhaps most original for the orchestral movement.
I believe your question implies the scherzo as it is currently used or known.
Instead of the traditional minuet, Haydn included a scherzo in each, and these movements quite literally represent the meaning of their name (Italian for "joke").
Haydn included other special effects as well, such as the birdcall which gives the third quartet its name.15.
So Beethoven used the term scherzo in three of his op.