Remove Special Characters in SQL Server

Below is code:

Create Function [dbo].[RemoveNonAlphaCharacters]
(
   @Temp VarChar(1000)
) 
Returns VarChar(1000) 
AS 
Begin 
 
    Declare @KeepValues as varchar(50) = '%[^a-z0-9]%' 
    While PatIndex(@KeepValues, @Temp) > 0 
        Set @Temp = Stuff(@Temp, PatIndex(@KeepValues, @Temp), 1, '') 
 
    Return @Temp 
End