Bootstrapping semi annual bond

I have a bond that pays out semi-annually. The coupon is 0.14, which means it pays 0.7 after 6 months, and then 100.7 after another 6 months. I need to find the discount factors by bootstrapping. Is the following approach corect: ZC1= 0.07 And, $$100= \frac{0.07}{1} + \frac{100.07}{(1+z)^2}$$, where z is the zero coupon rate for 1 year. Now my question is: should the discount factor for a year be $$\frac{1}{(1+z)^2}$$ or $$\frac{1}{(1+z/2)^2}$$

I'm new to finance, apologise if the doubt is too easy