if you want to always have it opened in vertical split with your current window, try next function:

augroup quickfix
    autocmd!
    autocmd QuickFixCmdPost [^l]* call OpenQuickFixList()
augroup END

function OpenQuickFixList()
    wincmd o
    vert cwindow
    wincmd p
    wincmd =
endfunction

What it does is

1. make current window the only one (:h wincmd)
2. vertically split cwindow
3. goes to previous window (remove this line if you want to stay in quickfix)
4. make windows equal

if you want to always have it opened in vertical split with your current window, try next function:

augroup quickfix
    autocmd!
    autocmd QuickFixCmdPost [^l]* call OpenQuickFixList()
augroup END

function OpenQuickFixList()
    wincmd o
    vert cwindow
    wincmd p
    wincmd =
endfunction

What it does is

1. make current window the only one (:h wincmd)
2. vertically split cwindow
3. goes to previous window (remove this line if you want to stay in quickfix)
4. make windows equal

PS