Transform grammar for repeating characters into LL(1)

Question

I have the following simple production rule:

S -> Sa | a

Which is left-recursive, and can recognize strings such as a or aa, etc

I tried to make it right-recursive, but I cannot find a way without creating ambigious grammars
(e.g.
S -> aS'
S' -> a | aS' )

Can someone explain how to make this grammar right-recursive and LL(1) form?