Excel doesn’t have a direct keyboard shortcut for superscript, but you can format text characters in the Format Cells dialog box—and Excel has a keyboard shortcut to open it.
Format text values as superscript
This works well when you want to present data in a visually appealing format. To format numeric values or formulas for a mathematical, chemical, or other type of technical expression, use the equation symbols and templates.
Select characters in a cell or cell range that you’d like to format.
Press CTRL+1 and under Effects, check the Superscript box, and click OK.
Tip: If you want to subscript the characters, like in H20, select Subscript instead.
Apply superscript or subscript to a numeric value
When you want to present a formula or an equation for numeric values:
Click Insert > Equation > Design.
Click Script and select the format you want.
Click the squares and type the values.
Tip: The equation box isn’t anchored to a cell and you can move, resize or rotate it using the handles.
Also check out formatting options for equations and formulas with the equation tools.