N-channel MESFETs fabricated in semi-insulating bulk 4H-SiC by nitrogen ion implantation (6x10(17) cm(-3) nitrogen concentration in the channel) using an aluminum Schottky gate metal and nickel ohmic contacts are studied for DC characteristics and deep level behavior. The pinch-off voltage, drain saturation current and transconductance of the MESFET are measured as -18V, similar to40 mA and 5.4 mS, respectively. Devices exhibited almost stable DC characteristics upto a temperature of 350degreesC. DLTS study revealed deep trap levels at energies 0.51 eV, 0.6 eV, 0.68 eV, 0.768 eV and 0.89 eV above the valence band edge E-v.