Increase the arc in a TikZ arrow

Question

This question is a spin-off from TikZ arrow misaligned in italicized text.

I'm drawing an arrow from one character to another within a word, using TikZ's \path edge[]. But the arrow's arc is so flat that it touches the arrowhead. Ideally, I would make the arc steeper. I assume I can do this by using TikZ's arc option (?), but I haven't been able to figure out how to properly use it, based on what I read in the pgf manual.

\documentclass{article}
\usepackage{fontspec,tikz}
    \setsansfont{Linux Biolinum O}
\begin{document}
\textsf{\textit{ac\tikz[baseline, remember picture] \node[inner sep = 0pt, anchor = base] (finisharrow){e};rn\tikz[baseline, remember picture] \node[inner sep = 0pt, anchor = base] (startarrow){a};}}
\begin{tikzpicture}[remember picture, overlay, shorten <=.2ex, shorten >=.2ex]
    \path[->, semithick](startarrow.70) edge[out = 90, in = 90] (finisharrow.70);
\end{tikzpicture}
\end{document}

Answer 1

Use loosenes=<value> to increase the radius of the arc:

\documentclass{article}
\usepackage{tikz}
\begin{document}
\textsf{\textit{ac\tikz[baseline, remember picture] \node[inner sep = 0pt, anchor = base] (finisharrow){e};rn\tikz[baseline, remember picture] \node[inner sep = 0pt, anchor = base] (startarrow){a};}}
\begin{tikzpicture}[remember picture, overlay, shorten <=.2ex, shorten >=.2ex]
    \path[->, semithick](startarrow.70) edge[out = 90, in = 90, looseness=2] (finisharrow.70);
\end{tikzpicture}
\end{document}