The charge-carrier mobility in most organic semiconductors that are useful for air-stable n-channel thin-film transistors (TFTs) is approximately one order of magnitude smaller than that in state-of-the-art p-channel TFTs [<I>Chem. Soc. Rev.</I> 39, 2643, 2010]. Therefore, the dynamic performance of air-stable organic complementary circuits is usually limited by the performance of the n-channel TFTs. To improve the dynamic characteristics of organic circuits, a common approach is to reduce the TFT channel length in order to increase the transconductance and reduce the gate capacitance. However, the drain current in short-channel organic TFTs and hence the speed of aggressively scaled circuits is often limited by the energy barrier at the interface between the semiconductor and the contacts. To some extent, this energy barrier can be reduced by choosing a contact metal with a work function matching the frontier orbital energy of the semiconductor [<I>J. Appl. Phys.</I> 96, 7312, 2004]. Further improvements are possible by contact doping, in the case of n-channel TFTs either with alkali metals, reduced semiconductor analogs, cationic dyes, or molecules with high-lying HOMO [<I>App. Phys. Lett.</I> 97, 243305, 2010]. Here we utilize the molecular dopant NDN-44 (Novaled) to reduce the contact resistance in air-stable hexadecafluorocopperphthalocyanine (F<SUB>16</SUB>CuPc) n-channel TFTs. The HOMO of the dopant is sufficiently high (-4.4 eV) to allow electron transfer to the LUMO of the semiconductor (-4.5 eV). Transistors with channel lengths between 1 and 60 µm were fabricated by vacuum deposition in combination with high-resolution silicon stencil masks [<I>IEDM</I>, 21.6, 2010]. The TFTs consist of Al gates, an AlOx/SAM gate dielectric (5.7 nm thick), the organic semiconductor (30 nm), and a thin dopant layer (~2.5 nm) deposited only underneath the Au top contacts. The linear-region mobilities of F<SUB>16</SUB>CuPc TFTs without doping (contact resistance: 48 kOhm-cm) range from 0.002 cm<SUP>2</SUP>/Vs (L = 1 µm) to 0.03 cm<SUP>2</SUP>/Vs (L = 60 µm). For TFTs with contact doping (contact resistance: 9 kOhm-cm) the mobilities are between 0.01 cm<SUP>2</SUP>/Vs (L = 1 µm) and 0.06 cm<SUP>2</SUP>/Vs (L = 60 µm). Since the off-state drain current (~ 1 pA) is not affected by the contact doping, the TFTs have an on/off current ratio as large as 10<SUP>7</SUP>. The contact doping greatly improves the linearity of the I<SUB>D</SUB>/V<SUB>DS</SUB> curves for small V<SUB>DS</SUB>. We also combined n-channel F<SUB>16</SUB>CuPc TFTs with p-channel dinaphtho[2,3-b:2’,3’-f]thieno[3,2-b] TFTs and realized air-stable organic complementary ring oscillators operating with low supply voltages (< 5 V). Incorporating NDN-44 as a contact dopant into the n-channel TFTs leads to a reduction in signal delay per stage from 30 µs to 20 µs (for a supply voltage of 3 V), confirming the potential of area-selective contact doping to improve the dynamic performance of organic n-channel TFTs and organic complementary circuits.